1. The document explains genetic crosses and Mendelian inheritance through examples of monohybrid and dihybrid crosses in pea plants.
2. It discusses key genetics concepts like genotype, phenotype, probability, Punnett squares, and inheritance patterns like complete dominance, incomplete dominance, and codominance.
3. As an example, a monohybrid cross between a homozygous dominant purple pea plant and a homozygous recessive white pea plant would result in all heterozygous purple offspring.
Heredity or Hereditary is the process of passing the traits and characteristics from parents to offsprings.
The offspring cells get their features and characteristics aka genetic information from their mother and father.
Heredity or Hereditary is the process of passing the traits and characteristics from parents to offsprings.
The offspring cells get their features and characteristics aka genetic information from their mother and father.
Genetic linkage is the tendency of DNA sequences that are close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction.
LINKAGE AND CROSSING-OVER SMG
A brief description of Linkage - Bateson and Punnett's Experiment on Sweet pea, Lathyrus odoratus, Coupling and Repulsion Theory, Complete and Incomplete Linkage, Significance of Linkage, Crossing-over: Cytological basis, Types, Factors influencing the frequency , Significance, Mitotic crossing-over
This PPT consists of 24 slides explaining Polygenic Inheritance . Some traits are controlled by two or more genes. These traits differ from Mendelian traits and donot show discrete alternative or contrasting forms and show continuous ranges. Examples of such traits are wheat seed colour, plant height, Human skin colour controlled by at least three genes showing many shades of dark and fare, human height, human eye colour etc
This power point presentation is designed to explain deviation of Mendelian dihybrid ratio due to interaction of genes which may be of following types
1.Two gene pairs affecting same character – 9:3:3:1
2.Epistasis, one gene hides effect of other
a) Recessive Epistasis - 9:3:4
b) Dominant epistasis - 12:3:1
3.Complementary genes - 9:7 ( 2 genes responsible for production of a particular phenotype )
4. Duplicate genes – 15:1 ( same effect given by either of two genes )
5. Polymeric gene action - 9:6:1
6. Inhibitory gene action - 13 : 3
Each interaction is typical in itself and ratios obtained are different
Genetics course notes for 6-7-8-9 grade life science, Compare and contrast asexual and sexual reproduction, also mitosis vs meiosis, Organization from the Human body to cell nucleus, DNA, gene, Alleles and protein creation. Homozygous dominant/recessive and Heterozygous w/example. Mutations Lock and key analogy. Punnet squares and pedigree problems
Genetic linkage is the tendency of DNA sequences that are close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction.
LINKAGE AND CROSSING-OVER SMG
A brief description of Linkage - Bateson and Punnett's Experiment on Sweet pea, Lathyrus odoratus, Coupling and Repulsion Theory, Complete and Incomplete Linkage, Significance of Linkage, Crossing-over: Cytological basis, Types, Factors influencing the frequency , Significance, Mitotic crossing-over
This PPT consists of 24 slides explaining Polygenic Inheritance . Some traits are controlled by two or more genes. These traits differ from Mendelian traits and donot show discrete alternative or contrasting forms and show continuous ranges. Examples of such traits are wheat seed colour, plant height, Human skin colour controlled by at least three genes showing many shades of dark and fare, human height, human eye colour etc
This power point presentation is designed to explain deviation of Mendelian dihybrid ratio due to interaction of genes which may be of following types
1.Two gene pairs affecting same character – 9:3:3:1
2.Epistasis, one gene hides effect of other
a) Recessive Epistasis - 9:3:4
b) Dominant epistasis - 12:3:1
3.Complementary genes - 9:7 ( 2 genes responsible for production of a particular phenotype )
4. Duplicate genes – 15:1 ( same effect given by either of two genes )
5. Polymeric gene action - 9:6:1
6. Inhibitory gene action - 13 : 3
Each interaction is typical in itself and ratios obtained are different
Genetics course notes for 6-7-8-9 grade life science, Compare and contrast asexual and sexual reproduction, also mitosis vs meiosis, Organization from the Human body to cell nucleus, DNA, gene, Alleles and protein creation. Homozygous dominant/recessive and Heterozygous w/example. Mutations Lock and key analogy. Punnet squares and pedigree problems
Biology 103 Laboratory Exercise – Genetic Problems
Introduction
Although the science of genetics has become a highly sophisticated discipline dealing
with the interactions of hereditary factors at the molecular level, it has its roots in the
basic laws of heredity initially discovered and presented by Gregor Mendel more than
one hundred years ago. Mendel's success in discovering these laws was due largely to his
application of the simple rules of mathematical probability - the laws of chance - to his
observations concerning the inheritance of certain characteristics in the garden pea plant.
Reginald Punnett and the Punnett Square
The Punnett square is a diagram used by biologists to determine genotypic probability
within the offspring from a particular genetic cross. The Punnett square shows every
possible genotypic combination of maternal alleles with the paternal alleles for a genetic
cross. Punnett squares only give probabilities for genotypes, not phenotypes. The square
diagram was designed by the British geneticist, Reginald Punnett (1865-1967) and first
presented to the science community in 1905. Punnett’s Mendelism (1905) is considered
the first popular science book to introduce genetics to the public.
Solving Genetic Problems
R
R'
R
RR RR'
R'
RR' R'R'
Maternal alleles
A
A
a
Aa
Aa
Paternal
Alleles
a
Aa
Aa
The first step in solving a genetic problem is to establish the genetic symbols you will use
in your problem solution. Stay consistent by using these same symbols throughout the
problem solving process.
Represent dominant and recessive alleles (different forms of a gene) using traditional
genetic symbols. Dominant alleles should be represented with the capital version of an
alphabetic letter while using the lower case version to show recessiveness. For example:
B = black color, b = white color.
Each individual gene or trait is diploid (2n) in nature and therefore, must be represented
with two alleles. Continuing with the alleles mentioned previously, an individual may
have the genetic makeup BB, Bb, or bb when using those alleles.
Remember that gametes (sperm and egg) are haploid (n) and can only provide one allele
per trait. For example: B or b
An individual’s genotype contains the possible gametes that can be expected to be
produced by that individual. Much of genetics revolves around the probability of the
makeup of gametes. If the individual is homozygous, all of the gametes produced will
possess the same kind of allele. For example, an individual with the genotype BB would
be expected to produce only B gametes and individuals with genotype bb would produce
only b gametes.
If the individual is heterozygous, that is the individual’s genotype contains one dominant
allele and one recessive allele (Bb), the gametes produced will possess one or the other of
the two forms of the gene – B or b. ...
Please answer all questionsDefine1. Wild type –2. Epistasis –.pdfdhavalbl38
Please answer all questions
Define
1. Wild type –
2. Epistasis –
Fill in the Blank
3. Two genes may interact effecting one trait and resulting in novel phenotypes with an F2
phenotypic ________________ ratio.
4. Under ________________ conditions, conditionally lethal mutants will die.
True or False
5. Penetrance is the degree or intensity with which a particular genotype is expressed in a
phenotype.
6. Continuous traits are usually controlled by multiple genes and may be influenced by the
environment.
Short Answer
7. Describe the inheritance pattern(s) of blood types.
8. When studying a newly discovered flowering plant in Costa Rica, you collect data on its petal
color in an effort to determine how this trait may be inherited. You find that 852 flowers are red,
331 are white and 389 are yellow. What are the possible inheritance patterns, and how could you
definitely conclude which of these possibilities is the true mode of inheritance?
Solution
Wild type- wild type phenotype refers to characteristics that occurs naturally in a breeding
population.
Epistasis - it refers to a phenomena when one gene’s expression is dependent on the presence of
another gene(s), called the modifier gene.
9:16
Let\'s take an example of comb varieties in chicken
We have two pure breeds : wyandotte whose phenotype is a rose comb and brahmas having the
phenotype of a pea comb, when crossed with each other, they create a completely new phenotype
of a walnut comb. Let\'s look at the ratio:
Parental cross: rose comb x pea comb
F1 : all walnut combs
F2 : 9 walnut : 3 rose: 3peas : 1 single
Hence the ratio is 9:16
Under the restrictive or nonpermissive condition conditions, conditionally lethal mutants will
die.
Conditionally lethal mutants are those which have an allele that will make the survival of the
species difficult only in a specific condition.
True. for example if a mutation in a gene gives the species a particular characterisitc which has
97%penetrance, only 97% of those with the mutation will develop that characteristic and 3 %
will not.
True. multiple genes affect continuous traits. For such complex gene interactions, the traits are
influenced by environmental factors too. For example, height and skin color.
There are four basic blood types which are A, B, AB and O and together with the Rh factor,
these can be +ve or -ve.
A and B are dominant, while O is recessive.
Blood type
A
B
O
A
A
AB
A
B
AB
B
B
O
A
B
O
For Rh factor, Rh (+)ve is dominant.
So if the any one or both parents have Rh (+)ve factor, the progeny will be Rh(+)ve.
If both parents are Rh(-)ve, the progeny will be Rh (-)ve
Father
Mother
D
D
d
Dd
Dd
d
Dd
Dd
100% Rh (+)ve children
Father
Mother
D
d
d
Dd
dd
d
Dd
dd
50% Rh(+)ve children
Red: 852
White: 331
Yellow:389
According to the given data, red is dominant and white is recessive and yellow is a result of
incomplete dominance of both white and red phenotype.
It can\'t be codominance, because codominance involves both phenotypes being expressed in
di.
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
Genetics- Chapter 5 - Principles of inheritance and variation.docxAjay Kumar Gautam
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, Moravian scientist and Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene.
GENETICS AND VARIATION -1
Genetics is a branch of science which deals with the study of inheritance and variation.
Definition of terms
Heredity
Is a passing of features from parents to their young.
Variation
Possessing of characteristics which are different from these of the parents and other offsprings.
Genotype
Is the genetic constitution or make up of an organism
Phenotype
Is the outward or physical appearance of an organism
Dominant gene
Is a gene that prevents the expression of another gene.
Recessive gene
Is a gene that is masked by another gene.
Homozygous
Is a condition where by the two genes for a given trait are similar/ alike
Heterogeneous
Is a condition where the two genes for a trait are different.
Gene
Is a part of chromosome that carries the genetic material called DNA. Are also referred to as nucleotide chemical units of inheritance arranged along the chromosomes. They are called hereditary factors.
a complete understanding of variation and genetics. how changes in genetics inherit and how genetically disease inherited... Complete info on Mendelian inheritence
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptx
Genetics Notes
1. GENETIC CROSSES Today Geneticists rely on Mendel’s work to Predict the likely outcome of Genetic Crosses. OBJECTIVES : Explain how probability is used to predict the results of genetic crosses. Use a Punnett square to predict the results of monohybrid and dihybrid crosses. Explain how a testcross is used to show the genotype of an individual whose phenotype is dominant. Differentiate a monohybrid cross from dihybrid cross. GENOTYPE AND PHENOTYPE 1. The Genetic Makeup of an organism is its GENOTYPE . The Genotype consists of the alleles that the organism inherits from its parents. 2. Pea plant flower color could be PP, Pp or pp. The P allele is the Dominant allele and represents purple flowers (PP or Pp). The p allele is the Recessive allele . Two Recessive alleles (pp) give white flowers. .
2. 3. The Physical Appearance of an organism as a result of its genotype is called PHENOTYPE. Ex. Color, Shape, Height, etc 4. The Phenotype of a PP or Pp pea plant is Purple Flowers. 5. The Phenotype of a pp pea plant is White Flowers. 6. When Both Alleles of a Pair are ALIKE , the organism is said to be HOMOZYGOUS for that characteristic. An organism may be Homozygous Dominant (genotype PP) or Homozygous Recessive (genotype pp). 7. When the Two Alleles in the Pair are DIFFERENT , the organism is HETEROZYGOUS (genotype Pp ) for that characteristic. PROBABILITY 1. Probability is the likelihood that a specific event will occur or is the likely outcome a given event will occur from random chance. 2. A Probability may be expressed as a Decimal (0.75), a Percentage (75%), or a Fraction (3/4).
3.
4. 3. Biologist use a Diagram called a PUNNETT SQUARE to aid in predicting the probability that certain traits will be inherited by offspring. 4. This tool provides a simple method to calculate probable results of a genetic cross. 5. In a Punnett square, all possible types of sperm alleles are lined up vertical, all possible egg alleles are lined up horizontally; every possible combination is placed in squares.
5.
6. Example 1: HOMOZYGOUS X HOMOZYGOUS P = Dominant Purple p = Recessive White 1. Genotype PP X Genotype pp. 2. The combination of Alleles in the Punnett Square indicate all the possible genotypes that can result from the cross. The predicted genotype is Pp every case. 3. There is a 100% probability that the offspring will have the Genotype Pp (Heterozygous Dominant) and the Phenotype purple flower color .
7. Example 2: HOMOZYGOUS X HETEROZYGOUS B = Dominant Black b = Recessive Brown 1. Genotype BB X Genotype Bb 2. The combination of Alleles in the Punnett Square indicates all the possible genotypes that can result from the cross. The predicted genotype BB is 2/4 or 50 % and the genotype Bb is 2/4 or 50 %. 3. There is a 50% probability that the offspring will have the Genotype BB (Homozygous Dominant) and the Phenotype Black . 4. There is a 50% probability that the offspring will have the Genotype Bb (Heterozygous dominant) and the Phenotype Black . 5. The probability of the Phenotype of Black coat in every case is 4/4 or 100%.
8. Example 3: HETEROZYGOUS X HETEROZYGOUS B = Dominant Black b = Recessive Brown 1. Genotype Bb X Genotype Bb 2. The combination of Alleles in the Punnett Square indicates all the possible genotypes that can result from the cross. The predicted genotype BB is 1/4 or 25 % and the genotype Bb is 2/4 (1/2) or 50 % and genotype bb is 1/4 or 25%. 3. 3/4 or 75% of the offspring from this cross are predicted to have a Black Coat and 1/4 or 25% of the offspring are predicted to have a Brown Coat . 4. The Ratio of the Genotypes that appear in offspring is called the GENOTYPIC RATIO (1:2:1). 5. The Ratio of the Phenotypes that appear in offspring is called the PHENOTYPIC RATIO (3:1).
9. Example 4: TESTCROSS 1. TESTCROSS are used to determine the genotype of an unknown individual. 2. You perform a Testcross in which an individual of unknown genotype is crossed with a Homozygous Recessive (bb) individual. 3. A Testcross can determine the Genotype of any individual whose Phenotype is dominant. Genotypes BB or Bb . 4. If the unknown genotype is homozygous black (BB), all offspring will be black. 5. If the genotype is heterozygous (Bb), about ½ the offspring will be black. 6. If the cross produces one brown offspring in a litter of eight, the genotype of the black coated parent is likely to be heterozygous, Bb .
10.
11.
12. 5. In four o’clocks both the Allele for Red Flowers (R) and the Allele for White Flowers (r) influence the Phenotype. 6. Neither Allele is completely dominant over the other Allele. 7. When four o’clocks self-pollinate , red flowering plants produce only red flowering offspring, and white flowering plants only produce white flowering offspring. 8. However, when red four o’clocks are crossed with white four o’clocks the F1 offspring all have pink flowers. 100% of the offspring of this cross have the Rr Genotype, which results in the Pink Phenotype.
13. Example 6: CODOMINANCE 1. CODOMINANCE occurs when Both Alleles for a gene are Expressed in a Heterozygous offspring. 2. In Codominance neither Allele is Dominant or Recessive, nor do alleles blend in the phenotype. 3. A Capital Letter is used for one allele (R), the other allele is a Capital Letter and apostrophe (R’). Giving the Genotype RR’. Example: Roan Cow or Horse. There are equal amounts of white hair and red hair blending together to give a color that is a combination of the two.
15. 1. A DIHYBRID CROSS is a cross between individuals that involves TWO Pairs of Contrasting Traits. 2. Predicting the results of a Dihybrid Cross is more complicated that predicting the results of a Monohybrid cross because there are more possible combinations. Example 1: HOMOZYGOUS X HOMOZYGOUS R = Dominant Round r = Recessive Wrinkled Y = Dominant Yellow y = Recessive Green 1. Suppose you wanted to predict the results of a cross between a pea plant that is homozygous for round, yellow seeds (RRYY), and one the is homozygous for wrinkled, green seeds (rryy).
16. 2. The Punnett square is used to predict the results of the cross, and contains 16 boxes. 3. The independently assorted alleles from one parent – RY, RY, RY, RY , listed along the left side of the Punnett Square. 3. The independently assorted alleles from one parent – ry, ry, ry, ry, listed along the top of the Punnett Square. 4. The Genotype for all the offspring of this cross will be Heterozygous for both Traits, RrYy , and the Phenotype of all the offspring will have Round and Yellow Seeds .
17. Example 2: HETEROZYGOUS X HETEROZYGOUS R = Dominant Round r = Recessive Wrinkled Y = Dominant Yellow y = Recessive Green 1. Crossing two Pea Plants Heterozygous for Round and Yellow Seeds, Genotype RrYy . 2. The Gametes for Both Parents will be RY, Ry, rY, ry . 3. The offspring of this Dihybrid Cross will have nine (9) different Genotypes.
18. 4. These nine Genotypes will result in pea plants with the following four (4) Phenotypes: 9/16 with round, yellow seeds (Genotypes RRYY, RRYy, RrYY, and RrYy) 3/16 with round green seeds (Genotypes RRyy, Rryy) 3/16 with wrinkled, yellow seeds (Genotypes rrYY and rrYy) 1/16 with wrinkled, green seeds (Genotype rryy) 5. A phenotypic ratio of 9:3:3:1 is expected when heterozygous for two traits are crossed.