This document provides an overview of genetics and key concepts from Gregor Mendel's experiments. It introduces Mendel's work with pea plants, the principles of inheritance he established including dominance, segregation and independent assortment. It explains genetic crosses such as monohybrid and dihybrid through the use of Punnett squares. The document also discusses examples of genetic inheritance patterns in humans including cystic fibrosis and Gaucher disease. It concludes with a brief overview of concepts beyond Mendelian genetics like incomplete dominance.
This document discusses several non-Mendelian patterns of inheritance including lack of dominance where the heterozygous phenotype differs from the homozygous phenotypes, multiple alleles where a single gene can have more than two alleles, pleiotropy where a single gene influences multiple traits, lethal genes which cause death, sex-linked inheritance determined by genes on sex chromosomes, gene interactions between two or more genes, complementary genes which act together to determine a trait, epistasis where one gene inhibits another, polygenic inheritance where multiple genes influence a trait, and pedigree analysis to trace traits within a family.
This document provides an overview of cytogenetic analysis and its history and applications. It discusses how cytogenetics has evolved from microscopic analysis using banding techniques to current hybrid techniques incorporating fluorescence in situ hybridization and array-based genomic analysis. It outlines some key developments in the field including the discovery of the correct human chromosome number, identification of chromosomal abnormalities associated with conditions like Down syndrome and cancer, and advances in banding and staining techniques that enabled better chromosome identification. It concludes by describing some common indications for cytogenetic analysis and providing details on normal human karyotypes and heteromorphisms.
This document discusses chromosomal abnormalities that can occur during meiosis due to errors in chromosome separation. Nondisjunction occurs when homologous chromosomes or sister chromatids fail to properly separate, resulting in gametes with an incorrect number of chromosomes. This can lead to conditions like Down syndrome (trisomy 21) where offspring have an extra copy of chromosome 21. Other abnormalities discussed include deletions, duplications, inversions, and translocations of chromosomal segments. Several human disorders caused by sex chromosome abnormalities are also outlined, such as Klinefelter syndrome, Turner syndrome, and Jacob's syndrome. Genomic imprinting is described as a phenomenon where phenotypic effects depend on whether genes are inherited from the mother or father.
Gregor Mendel conducted experiments with pea plants to study inheritance of traits from parents to offspring. He found that traits are determined by discrete units (now known as genes) that are passed from parents to offspring. Through his experiments with pea plants and statistical analysis, Mendel discovered that traits are dominant or recessive, and that alleles segregate and assort independently during gamete formation, known today as Mendel's Laws of Inheritance. Mendel's findings formed the basis of classical genetics.
Probability, Mendel, and Genetics PowerpointMrs. Henley
The document summarizes key concepts from Gregor Mendel's experiments with pea plants including:
- Mendel studied traits like plant height, seed shape and color in pea plants which existed in distinct forms (tall vs short, round vs wrinkled seeds)
- He performed controlled crosses between purebred (homozygous) pea plants and found that some traits were dominant over others in the offspring
- Mendel developed the concepts of dominant and recessive alleles and used Punnett squares to predict the probabilities of traits being expressed in offspring
Genetic inheritance and chromosomal disordersRakesh Verma
This document provides information about genetics, genetic inheritance, and chromosomal disorders. It defines key genetic terms like gene, allele, DNA, RNA, genetic code, and mutation. It describes different patterns of genetic inheritance such as autosomal dominant, autosomal recessive, X-linked recessive, and multifactorial inheritance. It also discusses different types of chromosomal abnormalities including aneuploidy, structural abnormalities like translocations, deletions, and inversions. Specific genetic and chromosomal disorders are described like Down syndrome, Klinefelter syndrome, and others. The document is a guide to genetics and chromosomal disorders.
This document discusses genetic concepts including genes, DNA, chromosomes, genotypes and phenotypes. It defines key terms and describes patterns of inheritance such as dominant, recessive, X-linked, autosomal and mitochondrial. Examples of genetic disorders and their inheritance patterns are provided. The document also contains sample genetics problems and their solutions.
This document discusses several non-Mendelian patterns of inheritance including lack of dominance where the heterozygous phenotype differs from the homozygous phenotypes, multiple alleles where a single gene can have more than two alleles, pleiotropy where a single gene influences multiple traits, lethal genes which cause death, sex-linked inheritance determined by genes on sex chromosomes, gene interactions between two or more genes, complementary genes which act together to determine a trait, epistasis where one gene inhibits another, polygenic inheritance where multiple genes influence a trait, and pedigree analysis to trace traits within a family.
This document provides an overview of cytogenetic analysis and its history and applications. It discusses how cytogenetics has evolved from microscopic analysis using banding techniques to current hybrid techniques incorporating fluorescence in situ hybridization and array-based genomic analysis. It outlines some key developments in the field including the discovery of the correct human chromosome number, identification of chromosomal abnormalities associated with conditions like Down syndrome and cancer, and advances in banding and staining techniques that enabled better chromosome identification. It concludes by describing some common indications for cytogenetic analysis and providing details on normal human karyotypes and heteromorphisms.
This document discusses chromosomal abnormalities that can occur during meiosis due to errors in chromosome separation. Nondisjunction occurs when homologous chromosomes or sister chromatids fail to properly separate, resulting in gametes with an incorrect number of chromosomes. This can lead to conditions like Down syndrome (trisomy 21) where offspring have an extra copy of chromosome 21. Other abnormalities discussed include deletions, duplications, inversions, and translocations of chromosomal segments. Several human disorders caused by sex chromosome abnormalities are also outlined, such as Klinefelter syndrome, Turner syndrome, and Jacob's syndrome. Genomic imprinting is described as a phenomenon where phenotypic effects depend on whether genes are inherited from the mother or father.
Gregor Mendel conducted experiments with pea plants to study inheritance of traits from parents to offspring. He found that traits are determined by discrete units (now known as genes) that are passed from parents to offspring. Through his experiments with pea plants and statistical analysis, Mendel discovered that traits are dominant or recessive, and that alleles segregate and assort independently during gamete formation, known today as Mendel's Laws of Inheritance. Mendel's findings formed the basis of classical genetics.
Probability, Mendel, and Genetics PowerpointMrs. Henley
The document summarizes key concepts from Gregor Mendel's experiments with pea plants including:
- Mendel studied traits like plant height, seed shape and color in pea plants which existed in distinct forms (tall vs short, round vs wrinkled seeds)
- He performed controlled crosses between purebred (homozygous) pea plants and found that some traits were dominant over others in the offspring
- Mendel developed the concepts of dominant and recessive alleles and used Punnett squares to predict the probabilities of traits being expressed in offspring
Genetic inheritance and chromosomal disordersRakesh Verma
This document provides information about genetics, genetic inheritance, and chromosomal disorders. It defines key genetic terms like gene, allele, DNA, RNA, genetic code, and mutation. It describes different patterns of genetic inheritance such as autosomal dominant, autosomal recessive, X-linked recessive, and multifactorial inheritance. It also discusses different types of chromosomal abnormalities including aneuploidy, structural abnormalities like translocations, deletions, and inversions. Specific genetic and chromosomal disorders are described like Down syndrome, Klinefelter syndrome, and others. The document is a guide to genetics and chromosomal disorders.
This document discusses genetic concepts including genes, DNA, chromosomes, genotypes and phenotypes. It defines key terms and describes patterns of inheritance such as dominant, recessive, X-linked, autosomal and mitochondrial. Examples of genetic disorders and their inheritance patterns are provided. The document also contains sample genetics problems and their solutions.
This document provides an outline for a lecture on patterns of inheritance. It covers the topics of genetics and human genetics, Mendel's laws of inheritance, Mendelian traits in humans, and monogenous diseases. The objectives are for students to understand general genetics concepts, key genetic terms, patterns of inheritance, Mendel's laws, and how they apply to inherited human traits and diseases. Example monogenetic diseases and Mendelian traits in humans are also listed.
Biology - Chp 11 - Introduction To Genetics - PowerPointMel Anthony Pepito
Gregor Mendel's experiments with pea plants in the mid-1800s laid the groundwork for genetics as a science. Through his work, Mendel discovered that traits are passed from parents to offspring through discrete factors that he called genes. He also described the principles of dominance, segregation, and independent assortment. Later, it was discovered that genes are located on chromosomes within cells and are passed from parents to offspring through the cellular process of meiosis. Meiosis results in gametes with half the normal chromosome number, allowing each parent to contribute one set of chromosomes to offspring.
The document provides information about meiosis and gametogenesis:
1) It explains the stages of meiosis including prophase I, metaphase I, anaphase I etc. and discusses genetic recombination through crossing over.
2) It discusses sex determination and gives examples of sex chromosome abnormalities.
3) It compares spermatogenesis and oogenesis, noting their differences in producing haploid gametes.
This document provides an overview of cytogenetics and chromosomal abnormalities. It begins with the history of cytogenetics, including the discovery of human chromosomes in 1882 and establishing the normal human karyotype of 46 chromosomes in 1956. It describes laboratory techniques for culturing and staining chromosomes, including various banding techniques. It discusses clinical cytogenetics and genetic counseling. It provides detailed explanations and examples of different types of numerical and structural chromosomal abnormalities, including aneuploidies, polyploidies, translocations, inversions, deletions and more. It explains the associated phenotypes and inheritance patterns of many common chromosomal syndromes.
MENDELE'S EXPERIMNENT AND TERMINOLOGY, BY MR. DINABANDHU BARAD, MSC TUTOR, DEPARTMENT OF PEDIATRIC, SUM NURSING COLLEGE, SIKSHA 'O' ANUSANDHAN DEEMED TO BE UNIVERSITY
- Gregor Mendel, an Augustinian monk in the late 1800s, is considered the founder of genetics for his experiments breeding pea plants. He studied traits like flower color, seed texture, and pod shape.
- Mendel discovered that traits are passed from parents to offspring through discrete units called genes, located on chromosomes. Genes come in different forms called alleles that give rise to different traits.
- Through experiments breeding thousands of pea plants, Mendel determined that alleles segregate and assort independently during reproduction according to his laws of inheritance. This laid the foundation for modern genetics.
Genetics is a branch of biology concerned with the study of genes, genetic variation, and heredity in organisms. Though heredity had been observed for millennia, Gregor Mendel, a scientist and Augustinian friar working in the 19th century, was the first to study genetics scientifically.
Gregor Mendel was an Augustinian monk who conducted breeding experiments with pea plants in the 1850s and 1860s. He studied seven traits in peas and found that traits are passed to offspring through discrete "factors" (now called genes). Mendel discovered that these factors segregate and assort independently during reproduction, resulting in predictable inheritance patterns. His work established the foundations of genetics but was not widely accepted until the early 20th century.
This document discusses sex-linked traits and how traits on the X chromosome can be inherited. It provides examples of traits like hemophilia, color blindness and baldness which are more commonly expressed in males due to them only having one X chromosome. Females have two X chromosomes so traits recessive on the X are less likely to be expressed phenotypically as females need two copies of the recessive allele. The document explains that while rare, it is possible for females to exhibit X-linked recessive traits if they inherit one recessive allele from their father and one from their mother who is a carrier.
Genetic variation in individual & population, polymorphism, Hardy-Weinberg Eq...maysoethu
Genetic variation exists between individuals and populations. This document discusses genetic variation and polymorphisms, including single nucleotide polymorphisms (SNPs). It also discusses allele frequencies, the odds ratio, and Hardy-Weinberg equilibrium. The document summarizes a research article that developed a multiplex assay using SNaPshot minisequencing to simultaneously screen for SNPs associated with fetal hemoglobin levels in genes like BCL11A and HBS1L-MYB.
15 the chromosomal basis of inheritancekindarspirit
This document summarizes a chapter from a biology textbook about the chromosomal basis of inheritance. It discusses how Mendel's theories of heredity were later linked to chromosomes through the experiments of Thomas Hunt Morgan using fruit flies. Morgan found that a white eye color mutant in male flies was located on the X chromosome, supporting the idea that genes have specific locations on chromosomes and explaining the patterns of inheritance. The chapter outlines Mendel's laws of segregation and independent assortment and how chromosome behavior during meiosis can account for these laws.
Although individual humans (and all diploid organisms) can only have two alleles for a given gene, multiple alleles may exist at the population level.
“Three or more kinds of gene which occupy the same locus are referred to as multiple alleles.”
Basic concepts of Genes, Chromosomes & DNA: Human Genome ProjectAnamika Ramawat
The document discusses the basic concepts of genetics including DNA, genes, chromosomes, and genetic inheritance. It provides definitions of key terms like gene, allele, and chromosome. It also summarizes the goals and accomplishments of the Human Genome Project, which aimed to map the entire human genome to better understand genes and hereditary traits.
Genetics is the study of genes and heredity. The document discusses key genetics concepts including chromosomes, DNA, genes, alleles, dominant and recessive traits, Punnett squares, sex-linked inheritance, and pedigrees. It provides examples to illustrate genetic inheritance patterns and the use of tools like Punnett squares and pedigrees to predict offspring traits.
Chromosomal rearrangements are gross changes in chromosomal morphology that can occur via radiation, mutagens, or repetitive sequences in DNA involved in non-homologous recombination. Rearrangements lead to chromosome breakage and "sticky ends" that are normally capped by telomeres to prevent mutation, but uncapped ends can cause duplications or deletions during meiosis. Heterozygous rearrangements often produce unbalanced gametes, giving rearrangements a heterozygous disadvantage that leads to their fixation in populations, and can cause reproductive isolation between populations with different rearrangements. Comparison of chromosome banding patterns has shown that rearrangements have occurred during primate evolution and may have contributed to speciation by trapping groups
This document discusses Gregor Mendel's laws of inheritance based on his experiments breeding pea plants. It defines key genetic terms and describes Mendel's three laws: 1) The Law of Dominance states that one allele is dominant over the recessive allele. 2) The Law of Segregation states that alleles segregate and pass to offspring independently during gamete formation. 3) The Law of Independent Assortment states that different genes assort independently of one another during gamete formation. Mendel's laws established basic principles of heredity and laid the foundation for genetics.
The document summarizes key concepts from chapters 8 and 9 about cellular reproduction and Mendel's experiments with pea plants. It describes:
1) The two main types of reproduction - asexual, which produces identical offspring, and sexual, which involves inheritance from two parents and produces variations.
2) How prokaryotes reproduce through binary fission, and eukaryotes go through interphase and mitosis/cytokinesis. Meiosis reduces the chromosome number in gametes.
3) Gregor Mendel's experiments in the abbey garden that discovered genes are inherited as discrete factors and laid the foundations for genetics through studying traits in pea plants.
This lecture covers the basics of genetics including an introduction to Gregor Mendel's experiments with pea plants, genetic terminology, monohybrid and dihybrid crosses using Punnett squares, Mendel's principles of inheritance, and concepts beyond Mendel like incomplete dominance. Key points covered include Mendel discovering the basic principles of heredity through studying traits in pea plants, how dominant and recessive alleles are inherited in monohybrid and dihybrid crosses according to his principles, and the concept of incomplete dominance in traits like flower color.
This document provides an overview of genetics and key concepts from Gregor Mendel's experiments. It introduces Mendel's work with pea plants and how he established the principles of heredity through monohybrid and dihybrid crosses. His work demonstrated that traits are inherited through discrete units called genes. The document also defines important genetic terminology and concepts such as dominant/recessive alleles, genotypes, phenotypes and Punnett squares. It discusses how Mendel's principles apply universally, using the example of cystic fibrosis inheritance in humans. The principle of independent assortment and exceptions like incomplete dominance in snapdragons are also summarized.
This document provides an outline for a lecture on patterns of inheritance. It covers the topics of genetics and human genetics, Mendel's laws of inheritance, Mendelian traits in humans, and monogenous diseases. The objectives are for students to understand general genetics concepts, key genetic terms, patterns of inheritance, Mendel's laws, and how they apply to inherited human traits and diseases. Example monogenetic diseases and Mendelian traits in humans are also listed.
Biology - Chp 11 - Introduction To Genetics - PowerPointMel Anthony Pepito
Gregor Mendel's experiments with pea plants in the mid-1800s laid the groundwork for genetics as a science. Through his work, Mendel discovered that traits are passed from parents to offspring through discrete factors that he called genes. He also described the principles of dominance, segregation, and independent assortment. Later, it was discovered that genes are located on chromosomes within cells and are passed from parents to offspring through the cellular process of meiosis. Meiosis results in gametes with half the normal chromosome number, allowing each parent to contribute one set of chromosomes to offspring.
The document provides information about meiosis and gametogenesis:
1) It explains the stages of meiosis including prophase I, metaphase I, anaphase I etc. and discusses genetic recombination through crossing over.
2) It discusses sex determination and gives examples of sex chromosome abnormalities.
3) It compares spermatogenesis and oogenesis, noting their differences in producing haploid gametes.
This document provides an overview of cytogenetics and chromosomal abnormalities. It begins with the history of cytogenetics, including the discovery of human chromosomes in 1882 and establishing the normal human karyotype of 46 chromosomes in 1956. It describes laboratory techniques for culturing and staining chromosomes, including various banding techniques. It discusses clinical cytogenetics and genetic counseling. It provides detailed explanations and examples of different types of numerical and structural chromosomal abnormalities, including aneuploidies, polyploidies, translocations, inversions, deletions and more. It explains the associated phenotypes and inheritance patterns of many common chromosomal syndromes.
MENDELE'S EXPERIMNENT AND TERMINOLOGY, BY MR. DINABANDHU BARAD, MSC TUTOR, DEPARTMENT OF PEDIATRIC, SUM NURSING COLLEGE, SIKSHA 'O' ANUSANDHAN DEEMED TO BE UNIVERSITY
- Gregor Mendel, an Augustinian monk in the late 1800s, is considered the founder of genetics for his experiments breeding pea plants. He studied traits like flower color, seed texture, and pod shape.
- Mendel discovered that traits are passed from parents to offspring through discrete units called genes, located on chromosomes. Genes come in different forms called alleles that give rise to different traits.
- Through experiments breeding thousands of pea plants, Mendel determined that alleles segregate and assort independently during reproduction according to his laws of inheritance. This laid the foundation for modern genetics.
Genetics is a branch of biology concerned with the study of genes, genetic variation, and heredity in organisms. Though heredity had been observed for millennia, Gregor Mendel, a scientist and Augustinian friar working in the 19th century, was the first to study genetics scientifically.
Gregor Mendel was an Augustinian monk who conducted breeding experiments with pea plants in the 1850s and 1860s. He studied seven traits in peas and found that traits are passed to offspring through discrete "factors" (now called genes). Mendel discovered that these factors segregate and assort independently during reproduction, resulting in predictable inheritance patterns. His work established the foundations of genetics but was not widely accepted until the early 20th century.
This document discusses sex-linked traits and how traits on the X chromosome can be inherited. It provides examples of traits like hemophilia, color blindness and baldness which are more commonly expressed in males due to them only having one X chromosome. Females have two X chromosomes so traits recessive on the X are less likely to be expressed phenotypically as females need two copies of the recessive allele. The document explains that while rare, it is possible for females to exhibit X-linked recessive traits if they inherit one recessive allele from their father and one from their mother who is a carrier.
Genetic variation in individual & population, polymorphism, Hardy-Weinberg Eq...maysoethu
Genetic variation exists between individuals and populations. This document discusses genetic variation and polymorphisms, including single nucleotide polymorphisms (SNPs). It also discusses allele frequencies, the odds ratio, and Hardy-Weinberg equilibrium. The document summarizes a research article that developed a multiplex assay using SNaPshot minisequencing to simultaneously screen for SNPs associated with fetal hemoglobin levels in genes like BCL11A and HBS1L-MYB.
15 the chromosomal basis of inheritancekindarspirit
This document summarizes a chapter from a biology textbook about the chromosomal basis of inheritance. It discusses how Mendel's theories of heredity were later linked to chromosomes through the experiments of Thomas Hunt Morgan using fruit flies. Morgan found that a white eye color mutant in male flies was located on the X chromosome, supporting the idea that genes have specific locations on chromosomes and explaining the patterns of inheritance. The chapter outlines Mendel's laws of segregation and independent assortment and how chromosome behavior during meiosis can account for these laws.
Although individual humans (and all diploid organisms) can only have two alleles for a given gene, multiple alleles may exist at the population level.
“Three or more kinds of gene which occupy the same locus are referred to as multiple alleles.”
Basic concepts of Genes, Chromosomes & DNA: Human Genome ProjectAnamika Ramawat
The document discusses the basic concepts of genetics including DNA, genes, chromosomes, and genetic inheritance. It provides definitions of key terms like gene, allele, and chromosome. It also summarizes the goals and accomplishments of the Human Genome Project, which aimed to map the entire human genome to better understand genes and hereditary traits.
Genetics is the study of genes and heredity. The document discusses key genetics concepts including chromosomes, DNA, genes, alleles, dominant and recessive traits, Punnett squares, sex-linked inheritance, and pedigrees. It provides examples to illustrate genetic inheritance patterns and the use of tools like Punnett squares and pedigrees to predict offspring traits.
Chromosomal rearrangements are gross changes in chromosomal morphology that can occur via radiation, mutagens, or repetitive sequences in DNA involved in non-homologous recombination. Rearrangements lead to chromosome breakage and "sticky ends" that are normally capped by telomeres to prevent mutation, but uncapped ends can cause duplications or deletions during meiosis. Heterozygous rearrangements often produce unbalanced gametes, giving rearrangements a heterozygous disadvantage that leads to their fixation in populations, and can cause reproductive isolation between populations with different rearrangements. Comparison of chromosome banding patterns has shown that rearrangements have occurred during primate evolution and may have contributed to speciation by trapping groups
This document discusses Gregor Mendel's laws of inheritance based on his experiments breeding pea plants. It defines key genetic terms and describes Mendel's three laws: 1) The Law of Dominance states that one allele is dominant over the recessive allele. 2) The Law of Segregation states that alleles segregate and pass to offspring independently during gamete formation. 3) The Law of Independent Assortment states that different genes assort independently of one another during gamete formation. Mendel's laws established basic principles of heredity and laid the foundation for genetics.
The document summarizes key concepts from chapters 8 and 9 about cellular reproduction and Mendel's experiments with pea plants. It describes:
1) The two main types of reproduction - asexual, which produces identical offspring, and sexual, which involves inheritance from two parents and produces variations.
2) How prokaryotes reproduce through binary fission, and eukaryotes go through interphase and mitosis/cytokinesis. Meiosis reduces the chromosome number in gametes.
3) Gregor Mendel's experiments in the abbey garden that discovered genes are inherited as discrete factors and laid the foundations for genetics through studying traits in pea plants.
This lecture covers the basics of genetics including an introduction to Gregor Mendel's experiments with pea plants, genetic terminology, monohybrid and dihybrid crosses using Punnett squares, Mendel's principles of inheritance, and concepts beyond Mendel like incomplete dominance. Key points covered include Mendel discovering the basic principles of heredity through studying traits in pea plants, how dominant and recessive alleles are inherited in monohybrid and dihybrid crosses according to his principles, and the concept of incomplete dominance in traits like flower color.
This document provides an overview of genetics and key concepts from Gregor Mendel's experiments. It introduces Mendel's work with pea plants and how he established the principles of heredity through monohybrid and dihybrid crosses. His work demonstrated that traits are inherited through discrete units called genes. The document also defines important genetic terminology and concepts such as dominant/recessive alleles, genotypes, phenotypes and Punnett squares. It discusses how Mendel's principles apply universally, using the example of cystic fibrosis inheritance in humans. The principle of independent assortment and exceptions like incomplete dominance in snapdragons are also summarized.
Genetics is the study of genes, heredity, and genetic variation. Gregor Mendel conducted experiments with pea plants in the 1800s and established the principles of inheritance, including dominance, segregation, and independent assortment. His work showed that traits are passed from parents to offspring through discrete units called genes. Monohybrid and dihybrid crosses examine the inheritance of one or two traits and can be represented using Punnett squares. Mendel's principles form the basis of modern genetics.
The document summarizes Gregor Mendel's experiments with pea plants that laid the foundation for the modern understanding of genetics and heredity. It discusses Mendel's observations of inherited traits in pea plants and how this led him to discover the three laws of inheritance: 1) the law of dominance, 2) the law of segregation, and 3) the law of independent assortment. It also explains some of Mendel's experimental methods and variables he controlled that contributed to his success, such as choosing simple and contrasting traits to study. Finally, it provides examples of genetic crosses and inheritance patterns including monohybrid and dihybrid crosses using Punnett squares.
This document provides an overview of genetics and Gregor Mendel's experiments with pea plants that established the basic principles of heredity and inheritance. It begins with an introduction to genetics, DNA, chromosomes, and heredity. It then discusses Gregor Mendel's biography and his experiments between 1856-1863, in which he studied seven traits of pea plants and developed the laws of segregation and independent assortment. The document explains Mendelian genetics concepts like genes, alleles, genotypes, phenotypes, monohybrid and dihybrid crosses. It provides examples of Mendelian inheritance patterns in human genetic disorders like cystic fibrosis and Gaucher disease. Finally, it discusses exceptions to Mendel
This document discusses genetics and inheritance. It defines key genetic terms like heredity, genetics, traits, genes, alleles, dominant/recessive alleles, heterozygous, homozygous, phenotype and genotype. It explains Mendel's principles of heredity through monohybrid crosses using pea plants and Punnett squares. A monohybrid cross of tall and dwarf plants results in all tall offspring in the F1 generation and a 3:1 phenotypic ratio in the F2 generation. Pedigrees are used to track inherited human traits through families.
This document provides an overview of basic Mendelian genetics and inheritance patterns. It discusses how Gregor Mendel conducted experiments with pea plants in the 1800s to discover the laws of inheritance. Through his work, he demonstrated that traits are passed from parents to offspring through discrete units called genes. The document also explains how monohybrid and dihybrid crosses can be used to predict inheritance patterns based on Mendel's laws of segregation and independent assortment. It uses the example of cystic fibrosis inheritance in humans to illustrate how recessive traits are expressed.
This document provides an overview of Gregor Mendel's experiments with pea plants and his discovery of the principles of heredity and genetic inheritance. It defines key genetic terminology and describes Mendel's experiments with monohybrid and dihybrid crosses using Punnett squares to predict offspring genotypes and phenotypes. It explains how Mendel's work laid the foundation for modern genetics through his demonstration that traits are passed from parents to offspring via discrete units later known as genes.
This document provides an introduction to genetics, including the basics of DNA structure, genes, chromosomes, heredity, and Gregor Mendel's experiments with pea plants that laid the foundations for genetics. It explains that DNA contains the genetic instructions passed down from parents to offspring, and that genes are segments of DNA located on chromosomes that influence traits. It summarizes Mendel's key conclusions from his experiments, including the laws of dominance, segregation, and independent assortment.
Unit v patterns ofinheritance mendelian inheritanceDeepa Lashkari
1. Gregor Mendel conducted breeding experiments with pea plants in the 1860s to study inheritance patterns of traits. Through his experiments, he discovered three laws of inheritance: the law of dominance, the law of segregation, and the law of independent assortment.
2. Mendel's experiments showed that factors (now known as genes) are passed unchanged from parents to offspring, and that inherited traits are determined by alternative versions (alleles) of these factors.
3. Mendel's laws explain inheritance of human traits and diseases such as cystic fibrosis, which follows a recessive pattern of inheritance where both parents must carry the recessive allele for a child to be affected.
Gregor Mendel conducted the first recorded scientific study of heredity by breeding pea plants. Through his experiments, he discovered that traits are passed from parents to offspring through discrete units (now known as genes). Mendel determined that some traits are dominant and will mask recessive traits, and that traits are inherited independently of each other. His work established the basic principles of genetics and heredity.
1. Mendel conducted experiments with pea plants to study inheritance of traits from parents to offspring. He found that traits separated and were transmitted independently during the formation of gametes.
2. His experiments showed that some traits are dominant over others and that offspring have predictable ratios of traits depending on the parents' genotypes.
3. Further work established his laws of inheritance including dominance, segregation, and independent assortment which explained patterns of inheritance.
Genetics
-. Basic Principles of Mendelian Genetics and Patterns of Inheritance
-Molecular Genetics & Inheritance
-. Protein Synthesis
- Mutations
-. Manipulation of DNA
-. ABO blood groups and Rh Factors
Evolution
- Theories on the origin of life on Earth
-. Theories of Evolution
1) The document discusses Mendelian genetics and provides explanations of key genetics concepts such as genotype, phenotype, dominant and recessive traits, monohybrid crosses, and Punnett squares.
2) It summarizes Gregor Mendel's experiments with pea plants and his discovery of the laws of segregation and independent assortment.
3) Examples of monohybrid crosses using Punnett squares are provided to predict offspring genotypes and phenotypes based on parental traits.
genetics introduction - models of inheritancemed zar
1. The document discusses genetics concepts including genes, alleles, genotypes, phenotypes, Mendel's laws of inheritance, and models of inheritance.
2. It provides examples of Mendel's experiments with pea plants and dihybrid crosses, demonstrating dominant and recessive traits.
3. Different inheritance patterns are described such as complete dominance, albinism, PKU, and blood types. Pedigree analysis is also discussed.
Gregor Mendel conducted experiments with pea plants in the 1850s and 1860s to study inheritance of traits. Through his experiments with over 28,000 pea plants, he discovered that traits are passed from parents to offspring through discrete factors, now known as genes. Mendel identified that for each trait, organisms inherit one gene from each parent, and that some genes are dominant and will always be expressed while others are recessive and only expressed when the dominant gene is not present. His work formed the basis of classical genetics and established the laws of segregation and independent assortment.
1. Gregor Mendel discovered genetics through experiments with pea plants. He found that traits separated and assorted independently during reproduction according to his laws of inheritance.
2. Genes determine traits and exist in different alleles that are passed from parents to offspring. Dominant alleles will be expressed over recessive alleles.
3. Mendel's experiments showed monohybrid and dihybrid inheritance followed predictable ratios through the generations. His work formed the foundations of classical genetics.
The document summarizes Gregor Mendel's experiments with pea plants and the principles of genetics that he discovered, including:
- Mendel was the first to study inheritance of traits through breeding experiments.
- He discovered the laws of segregation, independent assortment, dominance and recessiveness.
- Genes exist in pairs called alleles that determine traits, and can be dominant or recessive.
- Punnett squares can be used to predict the outcome of genetic crosses and determine probabilities.
- His work formed the basis of classical genetics and heredity.
Climate Change All over the World .pptxsairaanwer024
Climate change refers to significant and lasting changes in the average weather patterns over periods ranging from decades to millions of years. It encompasses both global warming driven by human emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. While climate change is a natural phenomenon, human activities, particularly since the Industrial Revolution, have accelerated its pace and intensity
Microbial characterisation and identification, and potability of River Kuywa ...Open Access Research Paper
Water contamination is one of the major causes of water borne diseases worldwide. In Kenya, approximately 43% of people lack access to potable water due to human contamination. River Kuywa water is currently experiencing contamination due to human activities. Its water is widely used for domestic, agricultural, industrial and recreational purposes. This study aimed at characterizing bacteria and fungi in river Kuywa water. Water samples were randomly collected from four sites of the river: site A (Matisi), site B (Ngwelo), site C (Nzoia water pump) and site D (Chalicha), during the dry season (January-March 2018) and wet season (April-July 2018) and were transported to Maseno University Microbiology and plant pathology laboratory for analysis. The characterization and identification of bacteria and fungi were carried out using standard microbiological techniques. Nine bacterial genera and three fungi were identified from Kuywa river water. Clostridium spp., Staphylococcus spp., Enterobacter spp., Streptococcus spp., E. coli, Klebsiella spp., Shigella spp., Proteus spp. and Salmonella spp. Fungi were Fusarium oxysporum, Aspergillus flavus complex and Penicillium species. Wet season recorded highest bacterial and fungal counts (6.61-7.66 and 3.83-6.75cfu/ml) respectively. The results indicated that the river Kuywa water is polluted and therefore unsafe for human consumption before treatment. It is therefore recommended that the communities to ensure that they boil water especially for drinking.
Improving the viability of probiotics by encapsulation methods for developmen...Open Access Research Paper
The popularity of functional foods among scientists and common people has been increasing day by day. Awareness and modernization make the consumer think better regarding food and nutrition. Now a day’s individual knows very well about the relation between food consumption and disease prevalence. Humans have a diversity of microbes in the gut that together form the gut microflora. Probiotics are the health-promoting live microbial cells improve host health through gut and brain connection and fighting against harmful bacteria. Bifidobacterium and Lactobacillus are the two bacterial genera which are considered to be probiotic. These good bacteria are facing challenges of viability. There are so many factors such as sensitivity to heat, pH, acidity, osmotic effect, mechanical shear, chemical components, freezing and storage time as well which affects the viability of probiotics in the dairy food matrix as well as in the gut. Multiple efforts have been done in the past and ongoing in present for these beneficial microbial population stability until their destination in the gut. One of a useful technique known as microencapsulation makes the probiotic effective in the diversified conditions and maintain these microbe’s community to the optimum level for achieving targeted benefits. Dairy products are found to be an ideal vehicle for probiotic incorporation. It has been seen that the encapsulated microbial cells show higher viability than the free cells in different processing and storage conditions as well as against bile salts in the gut. They make the food functional when incorporated, without affecting the product sensory characteristics.
Epcon is One of the World's leading Manufacturing Companies.EpconLP
Epcon is One of the World's leading Manufacturing Companies. With over 4000 installations worldwide, EPCON has been pioneering new techniques since 1977 that have become industry standards now. Founded in 1977, Epcon has grown from a one-man operation to a global leader in developing and manufacturing innovative air pollution control technology and industrial heating equipment.
Kinetic studies on malachite green dye adsorption from aqueous solutions by A...Open Access Research Paper
Water polluted by dyestuffs compounds is a global threat to health and the environment; accordingly, we prepared a green novel sorbent chemical and Physical system from an algae, chitosan and chitosan nanoparticle and impregnated with algae with chitosan nanocomposite for the sorption of Malachite green dye from water. The algae with chitosan nanocomposite by a simple method and used as a recyclable and effective adsorbent for the removal of malachite green dye from aqueous solutions. Algae, chitosan, chitosan nanoparticle and algae with chitosan nanocomposite were characterized using different physicochemical methods. The functional groups and chemical compounds found in algae, chitosan, chitosan algae, chitosan nanoparticle, and chitosan nanoparticle with algae were identified using FTIR, SEM, and TGADTA/DTG techniques. The optimal adsorption conditions, different dosages, pH and Temperature the amount of algae with chitosan nanocomposite were determined. At optimized conditions and the batch equilibrium studies more than 99% of the dye was removed. The adsorption process data matched well kinetics showed that the reaction order for dye varied with pseudo-first order and pseudo-second order. Furthermore, the maximum adsorption capacity of the algae with chitosan nanocomposite toward malachite green dye reached as high as 15.5mg/g, respectively. Finally, multiple times reusing of algae with chitosan nanocomposite and removing dye from a real wastewater has made it a promising and attractive option for further practical applications.
Optimizing Post Remediation Groundwater Performance with Enhanced Microbiolog...Joshua Orris
Results of geophysics and pneumatic injection pilot tests during 2003 – 2007 yielded significant positive results for injection delivery design and contaminant mass treatment, resulting in permanent shut-down of an existing groundwater Pump & Treat system.
Accessible source areas were subsequently removed (2011) by soil excavation and treated with the placement of Emulsified Vegetable Oil EVO and zero-valent iron ZVI to accelerate treatment of impacted groundwater in overburden and weathered fractured bedrock. Post pilot test and post remediation groundwater monitoring has included analyses of CVOCs, organic fatty acids, dissolved gases and QuantArray® -Chlor to quantify key microorganisms (e.g., Dehalococcoides, Dehalobacter, etc.) and functional genes (e.g., vinyl chloride reductase, methane monooxygenase, etc.) to assess potential for reductive dechlorination and aerobic cometabolism of CVOCs.
In 2022, the first commercial application of MetaArray™ was performed at the site. MetaArray™ utilizes statistical analysis, such as principal component analysis and multivariate analysis to provide evidence that reductive dechlorination is active or even that it is slowing. This creates actionable data allowing users to save money by making important site management decisions earlier.
The results of the MetaArray™ analysis’ support vector machine (SVM) identified groundwater monitoring wells with a 80% confidence that were characterized as either Limited for Reductive Decholorination or had a High Reductive Reduction Dechlorination potential. The results of MetaArray™ will be used to further optimize the site’s post remediation monitoring program for monitored natural attenuation.
Presented by The Global Peatlands Assessment: Mapping, Policy, and Action at GLF Peatlands 2024 - The Global Peatlands Assessment: Mapping, Policy, and Action
ENVIRONMENT~ Renewable Energy Sources and their future prospects.tiwarimanvi3129
This presentation is for us to know that how our Environment need Attention for protection of our natural resources which are depleted day by day that's why we need to take time and shift our attention to renewable energy sources instead of non-renewable sources which are better and Eco-friendly for our environment. these renewable energy sources are so helpful for our planet and for every living organism which depends on environment.
Recycling and Disposal on SWM Raymond Einyu pptxRayLetai1
Increasing urbanization, rural–urban migration, rising standards of living, and rapid development associated with population growth have resulted in increased solid waste generation by industrial, domestic and other activities in Nairobi City. It has been noted in other contexts too that increasing population, changing consumption patterns, economic development, changing income, urbanization and industrialization all contribute to the increased generation of waste.
With the increasing urban population in Kenya, which is estimated to be growing at a rate higher than that of the country’s general population, waste generation and management is already a major challenge. The industrialization and urbanization process in the country, dominated by one major city – Nairobi, which has around four times the population of the next largest urban centre (Mombasa) – has witnessed an exponential increase in the generation of solid waste. It is projected that by 2030, about 50 per cent of the Kenyan population will be urban.
Aim:
A healthy, safe, secure and sustainable solid waste management system fit for a world – class city.
Improve and protect the public health of Nairobi residents and visitors.
Ecological health, diversity and productivity and maximize resource recovery through the participatory approach.
Goals:
Build awareness and capacity for source separation as essential components of sustainable waste management.
Build new environmentally sound infrastructure and systems for safe disposal of residual waste and replacing current dumpsites which should be commissioned.
Current solid waste management situation:
The status.
Solid waste generation rate is at 2240 tones / day
collection efficiently is at about 50%.
Actors i.e. city authorities, CBO’s , private firms and self-disposal
Current SWM Situation in Nairobi City:
Solid waste generation – collection – dumping
Good Practices:
• Separation – recycling – marketing.
• Open dumpsite dandora dump site through public education on source separation of waste, of which the situation can be reversed.
• Nairobi is one of the C40 cities in this respect , various actors in the solid waste management space have adopted a variety of technologies to reduce short lived climate pollutants including source separation , recycling , marketing of the recycled products.
• Through the network, it should expect to benefit from expertise of the different actors in the network in terms of applicable technologies and practices in reducing the short-lived climate pollutants.
Good practices:
Despite the dismal collection of solid waste in Nairobi city, there are practices and activities of informal actors (CBOs, CBO-SACCOs and yard shop operators) and other formal industrial actors on solid waste collection, recycling and waste reduction.
Practices and activities of these actor groups are viewed as innovations with the potential to change the way solid waste is handled.
CHALLENGES:
• Resource Allocation.
Evolving Lifecycles with High Resolution Site Characterization (HRSC) and 3-D...Joshua Orris
The incorporation of a 3DCSM and completion of HRSC provided a tool for enhanced, data-driven, decisions to support a change in remediation closure strategies. Currently, an approved pilot study has been obtained to shut-down the remediation systems (ISCO, P&T) and conduct a hydraulic study under non-pumping conditions. A separate micro-biological bench scale treatability study was competed that yielded positive results for an emerging innovative technology. As a result, a field pilot study has commenced with results expected in nine-twelve months. With the results of the hydraulic study, field pilot studies and an updated risk assessment leading site monitoring optimization cost lifecycle savings upwards of $15MM towards an alternatively evolved best available technology remediation closure strategy.
Promoting Multilateral Cooperation for Sustainable Peatland management
mendelian genetics (1) (1).ppt
1. LECTURE 7 : GENETICS
• Introduction to Genetics and heredity
• Gregor Mendel – a brief bio
• Genetic terminology (glossary)
• Monohybrid crosses
• Patterns of inheritance
• Dihybrid crosses
• Test cross
• Beyond Mendelian Genetics – incomplete
dominance
2. Introduction to Genetics
• GENETICS – branch of biology that deals
with heredity and variation of organisms.
• Chromosomes carry the hereditary
information (genes)
• Arrangement of nucleotides in DNA
• DNA RNA Proteins
3. • Chromosomes (and genes) occur in pairs
Homologous Chromosomes
• New combinations of genes occur in sexual
reproduction
– Fertilization from two parents
4. Gregor Johann Mendel
• Austrian Monk, born in what is now Czech Republic in
1822
• Son of peasant farmer, studied
Theology and was ordained
priest Order St. Augustine.
• Went to the university of Vienna, where he
studied botany and learned the Scientific Method
• Worked with pure lines of peas for eight years
• Prior to Mendel, heredity was regarded as a "blending"
process and the offspring were essentially a "dilution"of
the different parental characteristics.
6. • In 1866 he published Experiments in Plant
Hybridization, (Versuche über Pflanzen-
Hybriden) in which he established his three
Principles of Inheritance
• He tried to repeat his work
in another plant, but didn’t
work because the plant
reproduced asexually! If…
• Work was largely ignored for
34 years, until 1900, when
3 independent botanists
rediscovered Mendel’s work.
7. • Mendel was the first biologist to use
Mathematics – to explain his results
quantitatively.
• Mendel predicted
The concept of genes
That genes occur in pairs
That one gene of each pair is
present in the gametes
8. Genetics terms you need to know:
• Gene – a unit of heredity;
a section of DNA sequence
encoding a single protein
• Genome – the entire set
of genes in an organism
• Alleles – two genes that occupy the same position
on homologous chromosomes and that cover the
same trait (like ‘flavors’ of a trait).
• Locus – a fixed location on a strand of DNA
where a gene or one of its alleles is located.
9. • Homozygous – having identical genes (one from
each parent) for a particular characteristic.
• Heterozygous – having two different genes for a
particular characteristic.
• Dominant – the allele of a gene that masks or
suppresses the expression of an alternate allele;
the trait appears in the heterozygous condition.
• Recessive – an allele that is masked by a
dominant allele; does not appear in the
heterozygous condition, only in homozygous.
10. • Genotype – the genetic makeup of an organisms
• Phenotype – the physical appearance
of an organism (Genotype + environment)
• Monohybrid cross: a genetic cross involving a
single pair of genes (one trait); parents differ by a
single trait.
• P = Parental generation
• F1 = First filial generation; offspring from a
genetic cross.
• F2 = Second filial generation of a genetic cross
11.
12. Monohybrid cross
• Parents differ by a single trait.
• Crossing two pea plants that differ in stem size,
one tall one short
T = allele for Tall
t = allele for dwarf
TT = homozygous tall plant
t t = homozygous dwarf plant
T T t t
13. Monohybrid cross for stem length:
T T t t
(tall) (dwarf)
P = parentals
true breeding,
homozygous plants:
F1 generation
is heterozygous:
T t
(all tall plants)
14. Punnett square
• A useful tool to do genetic crosses
• For a monohybrid cross, you need a square divided by
four….
• Looks like
a window
pane…
We use the
Punnett square
to predict the
genotypes and phenotypes of
the offspring.
15. Using a Punnett Square
STEPS:
1. determine the genotypes of the parent organisms
2. write down your "cross" (mating)
3. draw a p-square
Parent genotypes:
TT and t t
Cross
T T t t
16. Punnett square
4. "split" the letters of the genotype for each parent & put
them "outside" the p-square
5. determine the possible genotypes of the offspring by filling
in the p-square
6. summarize results (genotypes & phenotypes of offspring)
T t T t
T t T t
T T
t
t
Genotypes:
100% T t
Phenotypes:
100% Tall plants
T T t t
17. Monohybrid cross: F2 generation
• If you let the F1 generation self-fertilize, the next
monohybrid cross would be:
T t T t
(tall) (tall)
T T T t
T t t t
T t
T
t
Genotypes:
1 TT= Tall
2 Tt = Tall
1 tt = dwarf
Genotypic ratio= 1:2:1
Phenotype:
3 Tall
1 dwarf
Phenotypic ratio= 3:1
18. Secret of the Punnett Square
• Key to the Punnett Square:
• Determine the gametes of each parent…
• How? By “splitting” the genotypes of each parent:
If this is your cross T T t t
T T t t
The gametes are:
19. Once you have the gametes…
T T t t
T t T t
T t T t
T
T
t t
20. Shortcut for Punnett Square…
• You only need one box!
T T t t
T
t Genotypes:
100% T t
Phenotypes:
100% Tall plants
• If either parent is HOMOZYGOUS
T t
22. If you have another cross…
• A heterozygous with a homozygous
T t t t
T
t
t
T t
t t
Genotypes:
50% T t
50 % t t
Phenotypes:
50% Tall plants
50% Dwarf plants
You can
still use the
shortcut!
23. Another example: Flower color
For example, flower color:
P = purple (dominant)
p = white (recessive)
If you cross a homozygous Purple (PP) with a
homozygous white (pp):
P P p p
P p ALL PURPLE (Pp)
24. Cross the F1 generation:
P p P p
P P P p
P p p p
P
p
P p
Genotypes:
1 PP
2 Pp
1 pp
Phenotypes:
3 Purple
1 White
25. Mendel’s Principles
• 1. Principle of Dominance:
One allele masked another, one allele was
dominant over the other in the F1 generation.
• 2. Principle of Segregation:
When gametes are formed, the pairs of
hereditary factors (genes) become separated,
so that each sex cell (egg/sperm) receives
only one kind of gene.
26. Human case: CF
• Mendel’s Principles of Heredity apply universally
to all organisms.
• Cystic Fibrosis: a lethal genetic disease affecting
Caucasians.
• Caused by mutant recessive gene carried by 1 in
20 people of European descent (12M)
• One in 400 Caucasian couples will be both
carriers of CF – 1 in 4 children will have it.
• CF disease affects transport
in tissues – mucus is accumulated
in lungs, causing infections.
27. Inheritance pattern of CF
IF two parents carry the recessive gene of
Cystic Fibrosis (c), that is, they are
heterozygous (C c), one in four of their
children is expected to be homozygous for
cf and have the disease:
C C C c
C c c c
C c
C
c
C C = normal
C c = carrier, no symptoms
c c = has cystic fibrosis
28. Probabilities…
• Of course, the 1 in 4 probability of getting the
disease is just an expectation, and in reality,
any two carriers may have normal children.
• However, the greatest probability is for 1 in 4
children to be affected.
• Important factor when prospective parents are
concerned about their chances of having
affected children.
• Now, 1 in 29 Americans is a symptom-less
carrier (Cf cf) of the gene.
29. Gaucher Disease
• Gaucher Disease is a rare, genetic disease. It
causes lipid-storage disorder (lipids accumulate in
spleen, liver, bone marrow)
• It is the most common genetic disease affecting
Jewish people of Eastern European ancestry
(1 in 500 incidence; rest of pop. 1 in 100,000)
30. Dihybrid crosses
• Matings that involve parents that differ in two
genes (two independent traits)
For example, flower color:
P = purple (dominant)
p = white (recessive)
and stem length:
T = tall t = short
31. Dihybrid cross: flower color and
stem length
TT PP tt pp
(tall, purple) (short, white)
Possible Gametes for parents
T P and t p
F1 Generation: All tall, purple flowers (Tt Pp)
TtPp TtPp TtPp TtPp
TtPp TtPp TtPp TtPp
TtPp TtPp TtPp TtPp
TtPp TtPp TtPp TtPp
tp tp tp tp
TP
TP
TP
TP
32. Dihybrid cross: flower color and
stem length (shortcut)
TT PP tt pp
(tall, purple) (short, white)
Possible Gametes for parents
F1 Generation: All tall, purple flowers (Tt Pp)
T t P p
T P t p
T P
t p
33. Dihybrid cross F2
If F1 generation is allowed to self pollinate,
Mendel observed 4 phenotypes:
Tt Pp Tt Pp
(tall, purple) (tall, purple)
Possible gametes:
TP Tp tP tp
Four phenotypes observed
Tall, purple (9); Tall, white (3); Short, purple (3); Short white (1)
TTPP TTPp TtPP TtPp
TTPp TTpp TtPp Ttpp
TtPP TtPp ttPP ttPp
TtPp Ttpp ttPp ttpp
TP Tp tP tp
TP
Tp
tP
tp
34. Dihybrid cross
9 Tall purple
3 Tall white
3 Short purple
1 Short white
TTPP TTPp TtPP TtPp
TTPp TTpp TtPp Ttpp
TtPP TtPp ttPP ttPp
TtPp Ttpp ttPp ttpp
TP Tp tP tp
TP
Tp
tP
tp
Phenotype Ratio = 9:3:3:1
36. Principle of Independent Assortment
• Based on these results, Mendel postulated the
3. Principle of Independent Assortment:
“Members of one gene pair segregate
independently from other gene pairs during
gamete formation”
Genes get shuffled – these many combinations are
one of the advantages of sexual reproduction
37. Relation of gene segregation to
meiosis…
• There’s a correlation between the movement
of chromosomes in meiosis and the
segregation of alleles that occurs in meiosis
38. Test cross
When you have an individual with an unknown
genotype, you do a test cross.
Test cross: Cross with a homozygous recessive
individual.
For example, a plant with purple flowers can
either be PP or Pp… therefore, you cross the
plant with a pp (white flowers, homozygous
recessive)
P ? pp
39. Test cross
• If you get all 100% purple flowers, then the
unknown parent was PP…
P p P p
P p P p
P P
p
p
P p p p
P p p p
P p
p
p
•If you get 50% white,
50% purple flowers,
then the unknown
parent was Pp…
40. Dihybrid test cross??
If you had a tall, purple plant, how would you
know what genotype it is?
tt pp
?? ??
1. TTPP
2. TTPp
3. TtPP
4. TtPp
41. Beyond Mendelian Genetics:
Incomplete Dominance
Mendel was lucky!
Traits he chose in the
pea plant showed up
very clearly…
One allele was dominant over another, so
phenotypes were easy to recognize.
But sometimes phenotypes are not very
obvious…
42. Incomplete Dominance
Snapdragon flowers come in many colors.
If you cross a red snapdragon (RR) with a white
snapdragon (rr)
You get PINK flowers (Rr)!
R R
R r
r r
Genes show incomplete dominance
when the heterozygous phenotype
is intermediate.
44. What happens if you cross a pink with a white?
Incomplete dominance
A pink with a red?
45. Summary of Genetics
• Chromosomes carry hereditary info (genes)
• Chromosomes (and genes) occur in pairs
• New combinations of genes occur in sexual
reproduction
• Monohybrid vs. Dihybrid crosses
• Mendel’s Principles:
– Dominance: one allele masks another
– Segregation: genes become separated in gamete formation
– Independent Assortment: Members of one gene pair
segregate independently from other gene pairs during gamete
formation
46. Thanks! Remember:
• Quiz due on Thursday, February 19th.
• Review Session: Friday, February 20 TBA.
• Exam on Tuesday, February 24th