The determination of the sex in an animal is the complex system for deciding the sex of organism. it is depends on the chromosomes present in the animals. some animals determine the sex of an animal by external environmental factors.
This document discusses lethal alleles, which are alleles that cause death in an organism. It defines lethal alleles and provides a brief history of their discovery through early studies of coat color inheritance in mice. The document outlines four types of lethal alleles: early onset alleles that cause death early in life, late onset alleles that cause death late in life, conditional alleles that only cause death under certain environmental conditions, and semi-lethal alleles that only kill some individuals, not all. It provides the example of the Y gene in mice, which causes a yellow coat color but is lethal when present in the homozygous dominant state (YY), though not in the heterozygous or recessive states.
This document summarizes the molecular mechanisms of sex determination in Drosophila and humans. In Drosophila, sex is determined by the ratio of X chromosomes to autosomes (X:A ratio). A ratio greater than 1 leads to female development, while a ratio of less than 1 leads to male development. In humans, the presence of the SRY gene on the Y chromosome leads to testis development and a male phenotype, while its absence leads to ovarian development and a female phenotype. Key genes involved include Sxl, tra, and dsx in Drosophila, and SRY, Sox9, and FGF9 in humans. The document provides details on how these genes regulate downstream targets to control sexual differentiation in both organisms.
This document provides an overview of sex determination systems in animals. It discusses the main types of sex determination including environmental/non-genetic (influenced by temperature or location), chromosomal (XX-XO, XX-XY, etc.), and genic systems. For chromosomal sex determination, it describes the different mechanisms like XX-XO system found in grasshoppers and XY system common in humans and mice. It also discusses rare systems like haplodiploidy in bees and wasps.
Dosage compensation ∧ sex determination in drosophilazoosphere
Dosage compensation is the process where the total gene expression from a single X chromosome in one sex is made equal to the total gene expression from the two X chromosomes in the other sex. This can occur by up-regulating the single X chromosome or down-regulating the two X chromosomes. Failure to achieve dosage compensation is often lethal. The general organization of sex determination genes in Drosophila melanogaster includes master regulator genes, intermediate regulator genes, and terminal regulator genes that determine whether female or male development progresses.
Sex Determnation and sex based inheritance(Genetic)Azida Affini
Sex determination refers to the natural process by which an individual becomes male or female. In humans and most mammals, sex is genetically determined at fertilization by the XY sex determination system, where females have two X chromosomes and males have one X and one Y chromosome. The SRY gene on the Y chromosome triggers testes development, making the individual male. In females without a Y chromosome, ovaries develop. To compensate for differences in X chromosome dosage between males and females, one of the two X chromosomes is randomly inactivated in females.
Reference
Moeller, Karla T., "Temperature-Dependent Sex Determination in Reptiles". Embryo Project Encyclopedia (2013-02-01). ISSN: 1940-5030
Morjan, Carrie L. 2003. “How Rapidly Can Maternal Behavior Affecting Primary Sex Ratio Evolve in a Reptile with Environmental Sex Determination ?”
Shine, Richard. 1999. “Why Is Sex Determined by Nest Temperature in Many Reptiles?” 14(5): 186–89.
Wapstra, Erik et al. 2006. “Maternal Basking Behavior Determines Offspring Sex in a Viviparous Reptile.” : 230–32.
Crossing over occurs during meiosis when non-sister chromatids of homologous chromosomes exchange genetic material. It generates genetic diversity within populations that can drive evolution. The key steps are synapsis where homologs pair, duplication, exchange of segments between chromatids at chiasmata, and separation. Factors like distance, sex, temperature, chemicals, and radiation can influence crossing over rates. Significance includes proving linear gene arrangement, producing new combinations for evolution, and enabling genetic maps.
Sex determination can occur through chromosomal, genetic, environmental, or hormonal mechanisms. Chromosomal sex determination involves differences in sex chromosomes between males and females, such as XX/XY systems. Genetic sex determination is controlled by genes rather than chromosomes. Environmental sex determination involves environmental factors like temperature determining sex after fertilization. Hormonal determination refers to the role of hormones in coordinating sex differentiation. Sex is defined by differences in gamete size and type, with females producing large immobile eggs and males producing numerous small motile sperm.
This document discusses lethal alleles, which are alleles that cause death in an organism. It defines lethal alleles and provides a brief history of their discovery through early studies of coat color inheritance in mice. The document outlines four types of lethal alleles: early onset alleles that cause death early in life, late onset alleles that cause death late in life, conditional alleles that only cause death under certain environmental conditions, and semi-lethal alleles that only kill some individuals, not all. It provides the example of the Y gene in mice, which causes a yellow coat color but is lethal when present in the homozygous dominant state (YY), though not in the heterozygous or recessive states.
This document summarizes the molecular mechanisms of sex determination in Drosophila and humans. In Drosophila, sex is determined by the ratio of X chromosomes to autosomes (X:A ratio). A ratio greater than 1 leads to female development, while a ratio of less than 1 leads to male development. In humans, the presence of the SRY gene on the Y chromosome leads to testis development and a male phenotype, while its absence leads to ovarian development and a female phenotype. Key genes involved include Sxl, tra, and dsx in Drosophila, and SRY, Sox9, and FGF9 in humans. The document provides details on how these genes regulate downstream targets to control sexual differentiation in both organisms.
This document provides an overview of sex determination systems in animals. It discusses the main types of sex determination including environmental/non-genetic (influenced by temperature or location), chromosomal (XX-XO, XX-XY, etc.), and genic systems. For chromosomal sex determination, it describes the different mechanisms like XX-XO system found in grasshoppers and XY system common in humans and mice. It also discusses rare systems like haplodiploidy in bees and wasps.
Dosage compensation ∧ sex determination in drosophilazoosphere
Dosage compensation is the process where the total gene expression from a single X chromosome in one sex is made equal to the total gene expression from the two X chromosomes in the other sex. This can occur by up-regulating the single X chromosome or down-regulating the two X chromosomes. Failure to achieve dosage compensation is often lethal. The general organization of sex determination genes in Drosophila melanogaster includes master regulator genes, intermediate regulator genes, and terminal regulator genes that determine whether female or male development progresses.
Sex Determnation and sex based inheritance(Genetic)Azida Affini
Sex determination refers to the natural process by which an individual becomes male or female. In humans and most mammals, sex is genetically determined at fertilization by the XY sex determination system, where females have two X chromosomes and males have one X and one Y chromosome. The SRY gene on the Y chromosome triggers testes development, making the individual male. In females without a Y chromosome, ovaries develop. To compensate for differences in X chromosome dosage between males and females, one of the two X chromosomes is randomly inactivated in females.
Reference
Moeller, Karla T., "Temperature-Dependent Sex Determination in Reptiles". Embryo Project Encyclopedia (2013-02-01). ISSN: 1940-5030
Morjan, Carrie L. 2003. “How Rapidly Can Maternal Behavior Affecting Primary Sex Ratio Evolve in a Reptile with Environmental Sex Determination ?”
Shine, Richard. 1999. “Why Is Sex Determined by Nest Temperature in Many Reptiles?” 14(5): 186–89.
Wapstra, Erik et al. 2006. “Maternal Basking Behavior Determines Offspring Sex in a Viviparous Reptile.” : 230–32.
Crossing over occurs during meiosis when non-sister chromatids of homologous chromosomes exchange genetic material. It generates genetic diversity within populations that can drive evolution. The key steps are synapsis where homologs pair, duplication, exchange of segments between chromatids at chiasmata, and separation. Factors like distance, sex, temperature, chemicals, and radiation can influence crossing over rates. Significance includes proving linear gene arrangement, producing new combinations for evolution, and enabling genetic maps.
Sex determination can occur through chromosomal, genetic, environmental, or hormonal mechanisms. Chromosomal sex determination involves differences in sex chromosomes between males and females, such as XX/XY systems. Genetic sex determination is controlled by genes rather than chromosomes. Environmental sex determination involves environmental factors like temperature determining sex after fertilization. Hormonal determination refers to the role of hormones in coordinating sex differentiation. Sex is defined by differences in gamete size and type, with females producing large immobile eggs and males producing numerous small motile sperm.
This PPT consists of 15 slides only explaining Pleiotropy. This is a phenomenon when one gene controls more than one trait , the traits may be related .Generally one gene's product acts for many reactions and so can affect more than one trait. Examples can be seen in pea Coloured flower and pigmentation in leaf axil, frizzle trait in chicken, fur colour and deafness in cats,Human pleiotropic traits are PKU,Sickle cell Anaemia. HOsyndrome , p53 gene etc
Sex determination is the process by which an organism develops as male or female. It can be identified by morphological, anatomical and physiological characteristics. Historically it was determined based on primary and secondary sex characteristics, but scientific study began after the discovery of sex chromosomes in 1902. There are two main theories of sex determination - genetic theories involving sex chromosomes and physiological theories related to metabolic differences. In most species, including humans, the presence of two X chromosomes determines female development while one X and one Y chromosome determines male development.
Sex determination is controlled by sex chromosomes. In humans and many other species, females have two X chromosomes (XX) while males have one X and one Y chromosome (XY). The presence of a Y chromosome determines maleness, while its absence results in femaleness. There are two main systems - heterogametic males which include humans and heterogametic females found in some insects and fish. The ratio between X chromosomes and autosomes also influences sex determination in some species through a genic balance mechanism.
This document discusses sex determination and sex expression in animals. It defines key terms like sex chromosomes, autosomes, and allosomes. It describes four main mechanisms of sex determination: sex characters, chromosomal sex determination, monogenic sex determination, and environmental sex determination. For chromosomal sex determination, it provides details on the XX-XY, XX-XO, XO-XX, and ZW-ZZ systems. It also discusses genic balance theory and sex mosaicism in Drosophila.
This document discusses evolutionary theories around sexual selection and relationships. It explains that sexual selection occurs through intrasexual competition between males to attract females, and intersexual selection where females choose their mates. Research by Buss (1989) found cross-cultural differences in mate preferences, with females prioritizing resources and males prioritizing youth and attractiveness. Studies also show females' preferences change across their menstrual cycle and they favor more masculine traits when fertile. However, critics argue these theories are reductionist and deterministic by not accounting for free will or environmental influences on relationships.
One gene can influence multiple unrelated traits through pleiotropy. Pleiotropy occurs when a single gene affects multiple phenotypic traits through its effect on metabolic pathways. For example, phenylketonuria is caused by a mutation in the gene that codes for the enzyme phenylalanine hydroxylase. This single gene mutation can cause both mental retardation and reduced hair and skin pigmentation.
Sex determination is controlled genetically and establishes the development of sexual characteristics in organisms. The presence of XX chromosomes in females and XY chromosomes in males is responsible for sex determination in humans and most mammals. During meiosis, females produce only X-bearing eggs while males produce equal numbers of X- and Y-bearing sperm, leading to a 1:1 sex ratio at fertilization. Fusion of an X-bearing sperm produces a XX zygote that develops as a female, while an Y-bearing sperm combines to create a XY zygote that becomes a male.
Extrachromosomal inheritance involves the transmission of genetic traits from parent to offspring through cytoplasmic organelles like chloroplasts and mitochondria, rather than through nuclear genes. Three examples are given: (1) variegated leaves in four o'clock plants are inherited cytoplasmically, (2) streptomycin resistance in Chlamydomonas is inherited through chloroplasts, and (3) "poky" phenotype and abnormal cytochromes in Neurospora are inherited maternally through mitochondria. Cytoplasmic inheritance can also cause traits like cytoplasmic male sterility in plants. Maternal effects occur when the female parent's genotype influences offspring traits regardless of the male parent's genotype.
This document discusses linkage and crossing over of genes. It explains that genes located on the same chromosome are linked, and the closer they are, the stronger the linkage. Crossing over occurs during meiosis and leads to recombination of genes from homologous chromosomes. Linkage maps can be constructed by observing the frequency of crossing over between linked gene loci. These maps show the linear order and genetic distances between genes on chromosomes.
This theory proposes that hereditary traits are transmitted from one generation to the next through chromosomes and gametes. Gametes contain only one set of chromosomes and fuse during fertilization to restore the paired chromosome condition. Chromosomes are replicated and passed from parents to offspring, behaving in accordance with Mendel's laws of inheritance and explaining the mechanism of inheritance. Sex is determined by sex chromosomes, which can be of the XX-XY, ZZ-ZW, or XX-XO types.
This document discusses Mendelian and non-Mendelian inheritance. It provides examples of cytoplasmic inheritance including the inheritance of chloroplast genes in Mirabilis jalapa, where the phenotype is determined by the genotype of the female parent through cytoplasmic/plastid transmission, not the genes in the nucleus. It also discusses inheritance involving cytoplasmic particles like kappa particles in Paramecium, which are transmitted maternally but whose production is controlled by nuclear genes. The key differences between Mendelian and non-Mendelian inheritance are summarized in a table.
There are two main animal mating systems: monogamy and polygamy. Monogamy involves an animal having only one mate, while polygamy involves having multiple mates. Polygamy includes polygyny, where one male mates with multiple females, polyandry, where one female mates with multiple males, and polygynandry, where multiple males mate with multiple females. Polygyny is the most common type of polygamy in the animal kingdom. It provides advantages for males in increasing reproductive success but can negatively impact genetic diversity, while females may experience infanticide from new dominant males.
Crossing over refers to the exchange of genetic material between non-sister chromatids of homologous chromosomes during meiosis. It results in new combinations of genes and genetic variation. Crossing over occurs via the formation of chiasmata, where segments are exchanged between chromatids. It can involve two, three, or all four chromatids, and can be single, double, or multiple. Factors like temperature, radiation, age, and nutrition can influence the rate of crossing over. Its significance includes providing evidence for gene order and creating genetic variation important for breeding programs.
X inactivation is the process by which one of the two X chromosomes in female mammals is randomly inactivated. This occurs early in embryonic development through the expression of long non-coding Xist RNA from the future inactive X chromosome, which coats and silences that chromosome. Genes on the inactive X are transcriptionally silenced through epigenetic modifications, though some genes escape inactivation. The process ensures equal expression of X-linked genes between males and females through dosage compensation.
Maternal effects are the influences of a mothers genotype on the phenotype of her offspring. It results from the asymmetric contribution of the female parent to the development of zygotes.
In terms of chromosomal genes, both male and female parents contribute equally to the zygote. The female parent contributes to the zygotes initial cytoplasm and organelles. Sperm rarely contribute anything other than chromosomes. Therefore zygotic development begins within a maternal medium and hence the maternal cytoplasm directly affects zygotic development.
This document discusses polygenic inheritance, which is when multiple genes cumulatively control a phenotypic trait, rather than a single gene following Mendelian ratios. It provides skin color in humans as an example of polygenic inheritance controlled by multiple genes. The document outlines the ratios expected from two or three controlling genes, and shows how skin color ranges from light to dark depending on the number of dominant alleles present, with the most dominant alleles resulting in darker skin.
This document discusses Hardy-Weinberg equilibrium, which describes the expected genotype and allele frequencies in a population that is not evolving. It will be in equilibrium if 5 assumptions are met: large population size, no migration, negligible mutations, random mating, no natural selection. The model consists of two equations to calculate expected allele and genotype frequencies. Observed frequencies in a sample California population at the EST locus match the expected frequencies, indicating the population is in equilibrium at this locus and not evolving. However, the assumptions are often violated in real populations.
1. Genetic mapping involves determining the linear order and distance between linked genes on chromosomes through test crosses.
2. Key processes include determining linkage groups, calculating map distances in morgan or centimorgan units, and using two-point and three-point test crosses to order genes.
3. Maps are constructed by combining map segments and are useful for understanding inheritance, disease diagnosis, and evolution.
This document presents information about penetrance and expressivity for Sir Faisal Iqbal. It defines penetrance as the percentage of individuals that show expression of a mutant genotype. Expressivity reflects the range of expression of the mutant genotype. An example is given of the eyeless gene in flies, which can result in normal eyes to complete absence of eyes. Penetrance and expressivity are used to study the degree of expression of a trait quantitatively. Phenotypic mutations can occur due to reasons other than genotype, such as genetic background and environmental factors.
This document discusses sex determination in animals. It begins by defining sex and sex determination. It then describes the different mechanisms of sex determination, including environmental sex determination based on temperature, chromosomal sex determination involving sex chromosomes like XX/XY systems, and genic mechanisms involving single genes or balances of male and female determining genes. It provides examples for different sex determination systems in various animal groups like insects, birds, and mammals.
The document discusses sex determination and inheritance in humans and Drosophila. In both species, sex is determined by sex chromosomes, with females having two X chromosomes (homogametic) and males having one X and one Y chromosome (heterogametic). However, the mechanisms of sex determination differ between the two species. In humans, the Y chromosome contains the SRY gene which determines male development, while Drosophila uses a distinct mechanism.
This PPT consists of 15 slides only explaining Pleiotropy. This is a phenomenon when one gene controls more than one trait , the traits may be related .Generally one gene's product acts for many reactions and so can affect more than one trait. Examples can be seen in pea Coloured flower and pigmentation in leaf axil, frizzle trait in chicken, fur colour and deafness in cats,Human pleiotropic traits are PKU,Sickle cell Anaemia. HOsyndrome , p53 gene etc
Sex determination is the process by which an organism develops as male or female. It can be identified by morphological, anatomical and physiological characteristics. Historically it was determined based on primary and secondary sex characteristics, but scientific study began after the discovery of sex chromosomes in 1902. There are two main theories of sex determination - genetic theories involving sex chromosomes and physiological theories related to metabolic differences. In most species, including humans, the presence of two X chromosomes determines female development while one X and one Y chromosome determines male development.
Sex determination is controlled by sex chromosomes. In humans and many other species, females have two X chromosomes (XX) while males have one X and one Y chromosome (XY). The presence of a Y chromosome determines maleness, while its absence results in femaleness. There are two main systems - heterogametic males which include humans and heterogametic females found in some insects and fish. The ratio between X chromosomes and autosomes also influences sex determination in some species through a genic balance mechanism.
This document discusses sex determination and sex expression in animals. It defines key terms like sex chromosomes, autosomes, and allosomes. It describes four main mechanisms of sex determination: sex characters, chromosomal sex determination, monogenic sex determination, and environmental sex determination. For chromosomal sex determination, it provides details on the XX-XY, XX-XO, XO-XX, and ZW-ZZ systems. It also discusses genic balance theory and sex mosaicism in Drosophila.
This document discusses evolutionary theories around sexual selection and relationships. It explains that sexual selection occurs through intrasexual competition between males to attract females, and intersexual selection where females choose their mates. Research by Buss (1989) found cross-cultural differences in mate preferences, with females prioritizing resources and males prioritizing youth and attractiveness. Studies also show females' preferences change across their menstrual cycle and they favor more masculine traits when fertile. However, critics argue these theories are reductionist and deterministic by not accounting for free will or environmental influences on relationships.
One gene can influence multiple unrelated traits through pleiotropy. Pleiotropy occurs when a single gene affects multiple phenotypic traits through its effect on metabolic pathways. For example, phenylketonuria is caused by a mutation in the gene that codes for the enzyme phenylalanine hydroxylase. This single gene mutation can cause both mental retardation and reduced hair and skin pigmentation.
Sex determination is controlled genetically and establishes the development of sexual characteristics in organisms. The presence of XX chromosomes in females and XY chromosomes in males is responsible for sex determination in humans and most mammals. During meiosis, females produce only X-bearing eggs while males produce equal numbers of X- and Y-bearing sperm, leading to a 1:1 sex ratio at fertilization. Fusion of an X-bearing sperm produces a XX zygote that develops as a female, while an Y-bearing sperm combines to create a XY zygote that becomes a male.
Extrachromosomal inheritance involves the transmission of genetic traits from parent to offspring through cytoplasmic organelles like chloroplasts and mitochondria, rather than through nuclear genes. Three examples are given: (1) variegated leaves in four o'clock plants are inherited cytoplasmically, (2) streptomycin resistance in Chlamydomonas is inherited through chloroplasts, and (3) "poky" phenotype and abnormal cytochromes in Neurospora are inherited maternally through mitochondria. Cytoplasmic inheritance can also cause traits like cytoplasmic male sterility in plants. Maternal effects occur when the female parent's genotype influences offspring traits regardless of the male parent's genotype.
This document discusses linkage and crossing over of genes. It explains that genes located on the same chromosome are linked, and the closer they are, the stronger the linkage. Crossing over occurs during meiosis and leads to recombination of genes from homologous chromosomes. Linkage maps can be constructed by observing the frequency of crossing over between linked gene loci. These maps show the linear order and genetic distances between genes on chromosomes.
This theory proposes that hereditary traits are transmitted from one generation to the next through chromosomes and gametes. Gametes contain only one set of chromosomes and fuse during fertilization to restore the paired chromosome condition. Chromosomes are replicated and passed from parents to offspring, behaving in accordance with Mendel's laws of inheritance and explaining the mechanism of inheritance. Sex is determined by sex chromosomes, which can be of the XX-XY, ZZ-ZW, or XX-XO types.
This document discusses Mendelian and non-Mendelian inheritance. It provides examples of cytoplasmic inheritance including the inheritance of chloroplast genes in Mirabilis jalapa, where the phenotype is determined by the genotype of the female parent through cytoplasmic/plastid transmission, not the genes in the nucleus. It also discusses inheritance involving cytoplasmic particles like kappa particles in Paramecium, which are transmitted maternally but whose production is controlled by nuclear genes. The key differences between Mendelian and non-Mendelian inheritance are summarized in a table.
There are two main animal mating systems: monogamy and polygamy. Monogamy involves an animal having only one mate, while polygamy involves having multiple mates. Polygamy includes polygyny, where one male mates with multiple females, polyandry, where one female mates with multiple males, and polygynandry, where multiple males mate with multiple females. Polygyny is the most common type of polygamy in the animal kingdom. It provides advantages for males in increasing reproductive success but can negatively impact genetic diversity, while females may experience infanticide from new dominant males.
Crossing over refers to the exchange of genetic material between non-sister chromatids of homologous chromosomes during meiosis. It results in new combinations of genes and genetic variation. Crossing over occurs via the formation of chiasmata, where segments are exchanged between chromatids. It can involve two, three, or all four chromatids, and can be single, double, or multiple. Factors like temperature, radiation, age, and nutrition can influence the rate of crossing over. Its significance includes providing evidence for gene order and creating genetic variation important for breeding programs.
X inactivation is the process by which one of the two X chromosomes in female mammals is randomly inactivated. This occurs early in embryonic development through the expression of long non-coding Xist RNA from the future inactive X chromosome, which coats and silences that chromosome. Genes on the inactive X are transcriptionally silenced through epigenetic modifications, though some genes escape inactivation. The process ensures equal expression of X-linked genes between males and females through dosage compensation.
Maternal effects are the influences of a mothers genotype on the phenotype of her offspring. It results from the asymmetric contribution of the female parent to the development of zygotes.
In terms of chromosomal genes, both male and female parents contribute equally to the zygote. The female parent contributes to the zygotes initial cytoplasm and organelles. Sperm rarely contribute anything other than chromosomes. Therefore zygotic development begins within a maternal medium and hence the maternal cytoplasm directly affects zygotic development.
This document discusses polygenic inheritance, which is when multiple genes cumulatively control a phenotypic trait, rather than a single gene following Mendelian ratios. It provides skin color in humans as an example of polygenic inheritance controlled by multiple genes. The document outlines the ratios expected from two or three controlling genes, and shows how skin color ranges from light to dark depending on the number of dominant alleles present, with the most dominant alleles resulting in darker skin.
This document discusses Hardy-Weinberg equilibrium, which describes the expected genotype and allele frequencies in a population that is not evolving. It will be in equilibrium if 5 assumptions are met: large population size, no migration, negligible mutations, random mating, no natural selection. The model consists of two equations to calculate expected allele and genotype frequencies. Observed frequencies in a sample California population at the EST locus match the expected frequencies, indicating the population is in equilibrium at this locus and not evolving. However, the assumptions are often violated in real populations.
1. Genetic mapping involves determining the linear order and distance between linked genes on chromosomes through test crosses.
2. Key processes include determining linkage groups, calculating map distances in morgan or centimorgan units, and using two-point and three-point test crosses to order genes.
3. Maps are constructed by combining map segments and are useful for understanding inheritance, disease diagnosis, and evolution.
This document presents information about penetrance and expressivity for Sir Faisal Iqbal. It defines penetrance as the percentage of individuals that show expression of a mutant genotype. Expressivity reflects the range of expression of the mutant genotype. An example is given of the eyeless gene in flies, which can result in normal eyes to complete absence of eyes. Penetrance and expressivity are used to study the degree of expression of a trait quantitatively. Phenotypic mutations can occur due to reasons other than genotype, such as genetic background and environmental factors.
This document discusses sex determination in animals. It begins by defining sex and sex determination. It then describes the different mechanisms of sex determination, including environmental sex determination based on temperature, chromosomal sex determination involving sex chromosomes like XX/XY systems, and genic mechanisms involving single genes or balances of male and female determining genes. It provides examples for different sex determination systems in various animal groups like insects, birds, and mammals.
The document discusses sex determination and inheritance in humans and Drosophila. In both species, sex is determined by sex chromosomes, with females having two X chromosomes (homogametic) and males having one X and one Y chromosome (heterogametic). However, the mechanisms of sex determination differ between the two species. In humans, the Y chromosome contains the SRY gene which determines male development, while Drosophila uses a distinct mechanism.
- The document provides information and instructions for an upcoming exam.
- Students should arrive early to review and should not be late, as arriving more than 15 minutes late will result in a zero grade.
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- Seating will be assigned before the exam starts. Answer keys will be posted after the exam but no photos are allowed. Grades will be posted as soon as possible. Cheating is not allowed.
The document provides information and instructions for an upcoming exam. It advises students to arrive early to review and relax, as arriving even a minute late could result in a zero grade. All personal items must be placed at the front of the room, and only a pencil and eraser are allowed during the exam. Use of any electronic devices will result in a zero. Students must write their name on the exam paper and Scantron, and bring a photo ID and student number to turn in the materials. Answer keys will be posted after the exam without photos allowed. Grades will be posted as soon as possible. Cheating is strictly prohibited.
Sex determination is controlled genetically and involves the sex chromosomes. In humans and most mammals, females have two X chromosomes (XX) while males have one X and one Y chromosome (XY). At fertilization, if an X-bearing sperm fertilizes the egg, an XX zygote develops into a female, while a Y-bearing sperm results in an XY male zygote. Different organisms use different sex determination systems, such as XX/XY in humans and Drosophila, XO/XX in insects, and WZ/WW in birds.
Sex identification by Rohit Kumar ppt HnbguSkyeHarris3
This document summarizes sex identification in genetics. It discusses the key types of sex chromosomes, including autosomes and sex chromosomes. It describes the two main mechanisms of sex determination: heterogametic males (XY in humans and XX-XO in grasshoppers) and heterogametic females (ZW-ZZ in birds and ZO-ZZ in moths). It also briefly explains the genic balance mechanism discovered by Bridges and environmental sex identification in the sea worm Bonellia viridis. The purpose is to explain how sex chromosomes are responsible for sex identification.
Sex determination in animals and plantsSakeena Asmi
This document discusses various mechanisms of sex determination in animals and plants. It begins by defining sex biologically and describing the basic chromosomal mechanisms of sex determination, including XX-XY and ZW sex determination systems. It then goes into more detail about specific examples like sex determination in Drosophila, humans, and plants. Other mechanisms discussed include XO sex determination, haplodiploidy in hymenoptera, genic balance theory, single gene effects, and cytoplasmic sex determination. Sex differentiation through hormonal effects is also summarized.
Sex-determination and Sex-linked Inheritance.pptxSeemaGaikwad15
The sexually reproducing organisms are classified into two types such as monoecious (hermaphrodite) and dioecious. In monoecious organisms, both male and female gametes (sex cells) are produced by a single individual. The organisms in which both male and female gametes are produced by different individuals are called dioecious. Living organisms, with a very few exceptions, are differentiated into male and female individuals. The sexes of the individuals are genetically determined.
The biological system that determines the development of sexual characteristics in an organism is called sex determination.
There are two different systems of sex determination- Chromosomal sex determination and Non-genetic sex determination.
Sex determination can occur through chromosomal, hormonal, or environmental means. Chromosomal sex determination involves allosomes (sex chromosomes) like X and Y that determine if an offspring is male or female. In humans and fruit flies, females are XX and males are XY. The sperm determines sex as it carries either X or Y. Some insects like grasshoppers are XO, with females XX and males XO. Birds can be ZW female and ZZ male. The egg determines sex. Honeybee sex is determined by fertilization - fertilized eggs are female, unfertilized are male.
This document discusses different systems of sex determination and inheritance in mammals, insects, and birds. It describes the XY, ZW, and X0 systems which use sex chromosomes like X and Y, Z and W, or just X to determine whether an offspring develops as male or female. It also defines sex-limited traits which are expressed in only one sex, sex-influenced traits which are expressed differently in males and females, and sex-linked traits located on sex chromosomes that are inherited differently between sexes. Examples of each type of trait are provided.
Sex determination is the process by which an individual develops into a male or female based on their sex chromosomes. In humans, females have two X chromosomes (XX) while males have one X and one Y chromosome (XY). The presence of a Y chromosome triggers male development while its absence results in female development, with sex being governed by genes on the sex chromosomes. Human body cells normally contain 23 pairs of chromosomes, including 22 pairs of autosomes that do not determine sex and one pair of sex chromosomes that do signal sex determination.
This document discusses sex chromosomes and sex determination in humans. It notes that humans normally have 23 pairs of chromosomes, including one pair of sex chromosomes that are XX in females and XY in males. The Y chromosome determines male sex development, while the absence of a Y chromosome allows for female development. Rare conditions like Down syndrome and hermaphroditism are also discussed briefly in terms of their effects on sex chromosomes or development.
Chromosomal theory of heredity. Genetics of a sexEneutron
Chromosomal theory of heredity states that chromosomes, not just traits, are inherited. It was developed in 1902 and linked Mendel's work on genes to chromosome behavior. The key points are: chromosomes contain genes and are inherited in pairs from parents; during meiosis homologous chromosomes separate so gametes receive one of each; fertilization restores chromosome pairs. Later, researchers discovered that some genes are linked if on the same chromosome and can be mapped based on recombination rates. Sex chromosomes also carry traits, with mutations on the X chromosome being sex-linked in many species.
This document discusses mechanisms of sex determination in living organisms. It begins by explaining that sex is determined by the type of sex cell (gamete) produced - male or female. It then describes several mechanisms, including:
1. Chromosomal mechanisms, where sex is determined by sex chromosomes (X/Y in many mammals including humans, X/O in some insects).
2. Genic balance and environmental mechanisms.
It focuses on chromosomal mechanisms, explaining XY and ZW systems where the heterogametic sex determines offspring sex. The majority of the document provides details on chromosomal sex determination in various species.
Sex chromosomes determine an organism's sex. In most animals, females have two of the same sex chromosome (XX) while males have two different ones (XY). Some organisms use other systems like ZW chromosomes. The discovery of sex chromosomes began in the late 1800s with observations of fireflies and grasshoppers. Sex is also determined by factors like temperature, parasites, size, metabolism and hormones in some species. In humans, the Y chromosome carries the SRY gene which triggers testis development.
This document summarizes different mechanisms of sex determination in animals. It discusses chromosomal sex determination mechanisms including XX-XO type (found in grasshoppers and aphids), XX-XY type (found in humans), ZZ-ZW type (found in birds), and haplodiploid type. It also covers environmental sex determination influenced by factors like temperature (in crocodiles and turtles) and location (in Bonellia viridis). Sex determination in Drosophila depends on the ratio of X chromosomes to autosomes. The document concludes that the key to maleness and femaleness ultimately lies in the control of gene expression.
This document discusses chromosomal sex determination in humans. It begins by defining sex determination as the genetic mechanism that establishes distinction between male and female. It then describes the two types of chromosomes - autosomes and sex chromosomes. In humans, sex is determined by an XX-XY system, where females have two X chromosomes and males have one X and one Y chromosome. The Y chromosome contains genes that trigger male development, overriding the default female development directed by the X chromosome. Therefore, chromosomal sex determination in humans is of the heterogametic male type, where males produce two different gamete types (X and Y sperm) while females are homogametic and produce a single type of gamete (X eggs).
Sex determination - chromosomal theory of sex determination.Jennifer Joy
This document summarizes the chromosome theory of sex determination. It discusses the discovery of sex chromosomes and their different structures in males and females. There are two main types of sex determination mechanisms: XX-XY systems where females are XX and males are XY, and ZW-ZZ systems where females are ZW and males are ZZ. In both systems, the sex is determined by which sex chromosomes are present in the fertilized egg - an XX, XY, ZW, or ZZ combination will develop into a female or male. The document provides examples of different species that use each type of sex determination system.
This document discusses different mechanisms of sex determination in organisms, including environmental sex determination, chromosomal sex determination, and genic balance theory. It provides examples for each mechanism. It also describes the XX-XO type of chromosomal sex determination in more detail, noting that females are XX and homogametic while males are XO and heterogametic. Some organisms like grasshoppers and nematodes use this XX-XO system.
The powerpoint presentation on blood pressure covers all the aspects of blood pressure, measurement of blood pressure and factors affecting blood pressure. it also explained the Hypertension and Hypotension in detail.
The dynamics of movement of xenobiotics in the living system from its penetration into the blood to its final elimination from the body is termed translocation. Translocation of the toxicants is completed by absorption, distribution, biotransformation and excretion.
Classical and molecular taxonomic parameters, species concept, systematic gradation of animals, nomenclature, modern scheme of animal classification into sub-Kingdom, division, section, phyla and minor phyla
The adrenal glands are located above each kidney and are composed of an outer adrenal cortex and inner adrenal medulla. The adrenal cortex secretes mineralocorticoids like aldosterone to regulate sodium levels, glucocorticoids like cortisol to regulate proteins, carbohydrates, and lipids, and androgens. The adrenal medulla secretes epinephrine and norepinephrine in response to stress which increases heart rate, blood pressure, and blood flow to prepare the body for fight or flight.
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...AbdullaAlAsif1
The pygmy halfbeak Dermogenys colletei, is known for its viviparous nature, this presents an intriguing case of relatively low fecundity, raising questions about potential compensatory reproductive strategies employed by this species. Our study delves into the examination of fecundity and the Gonadosomatic Index (GSI) in the Pygmy Halfbeak, D. colletei (Meisner, 2001), an intriguing viviparous fish indigenous to Sarawak, Borneo. We hypothesize that the Pygmy halfbeak, D. colletei, may exhibit unique reproductive adaptations to offset its low fecundity, thus enhancing its survival and fitness. To address this, we conducted a comprehensive study utilizing 28 mature female specimens of D. colletei, carefully measuring fecundity and GSI to shed light on the reproductive adaptations of this species. Our findings reveal that D. colletei indeed exhibits low fecundity, with a mean of 16.76 ± 2.01, and a mean GSI of 12.83 ± 1.27, providing crucial insights into the reproductive mechanisms at play in this species. These results underscore the existence of unique reproductive strategies in D. colletei, enabling its adaptation and persistence in Borneo's diverse aquatic ecosystems, and call for further ecological research to elucidate these mechanisms. This study lends to a better understanding of viviparous fish in Borneo and contributes to the broader field of aquatic ecology, enhancing our knowledge of species adaptations to unique ecological challenges.
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
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Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
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Exposé invité Journées Nationales du GDR GPL 2024
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
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11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
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2. • Two sexes- Male and Female
• Sex in animal is determined by chromosomes
• Chromosomes:
– Autosomes- they are found in all cells. The genes situated
in the autosomes are responsible for determination of
somatic characters
– Sex chromosomes: they are variously named as ‘X’ and ‘Y’
chromosomes, ‘Z’ and ‘W’ chromosomes, idiosomes,
heterosomes or allosomes. The genes which determine sex
are located on these chromosomes.
3. Theories of sex determination
• According to Hicker (1920), embryologically sex-determination
can be classified into three groups
a) Progamic: When sex is determined before fertilization
b) Syngamic: When sex is determined at the time of
fertilization and
c) Epigamic: sex is determined after the formation of the
zygote i.e. after fertilization
The modern theories of sex determination belong to the
syngamic and epigamic type and are mainly the
chromosomal theory, the genic balance theory, the
hormonal theory and the environmental theory
4. Chromosomal theory of sex determination
• Proposed by Miss Stevens (1905) and is supported by Bridges
(1922) and Goldschmidt (1938)
• According to this theory the chromosome is the main factor to
determine the sex
• Two types of chromosomes in an organism- Autosomes and
Allosomes
• Allosomes are sex chromosomes
• Two types of sex chromosomes ‘X’ and ‘Y’
• X chromosome:
– Larger. Straight, contain large amount of euchromatin and
small amount of heterochromatin
• Y chromosome:
– Smaller, bend at one end contain small amount of euchromatin
and large amount of heterochromatin
• Chromosomal theory is the theory of heterogenesis
5.
6. Theory of heterogenesis
• It was proposed by Correns in 1906
• According to this theory, one sex produced two types of gametes
and such individual is called as heterogametic. The other sex
produces the same type of gametes such individual are called
homogametic
7. XX-XY Method
• Male : Heterogametic and has XY chromosome
• Female : Homogametic and has XX chromosome
• Example : Sex determination in human
8. ZW-ZZ Method
• This type of sex determination is found in animals such as
butterflies, moths, birds and some fishes
• It is just reverse of the XX-XY method
• Male- Homogametic (ZZ), Female- Heterogametic (ZW)
• Z and W letters are used instead of X and Y respectively
• In male- 8 pairs of autosomes + ZZ
• In female- 8 pairs of autosomes + ZW
9. XX-XO Method
• In some nematodes, spiders and insects, the Y chromosome is
absent
• It occurs in most insects of the order Hemoptera and Orthoptera
(Cockroaches and Grasshopper)
• The letter ‘O’ means zero and
indicate absence of
chromosomes in one sex i.e.
Male (XO)
• In 1902 C. E. McClung reported
the absence of one
chromosome from grasshopper
testes, he found 11 pairs of
chromosomes with one odd
chromosome (23 chr) in male in
female germ cells number are
24
10. ZO-ZZ Method
• This method derived from the basic ZW-ZZ method, in which male
is homogametic (ZZ) and female is heterogametic (ZW)
• In ZZ-ZO method W chromosome is lost in female
• Here ‘O’ denotes the absence of sex chromosome
• Therefore female is heterogametic produces two types of egg Z
and O
11. Sex determination in Drosophila- Genic balance theory
• Proposed by Calvin B. Bridges in 1921
• Female sex determining genes are located on X chromosomes
while the male sex determining genes are located on autosomes
• Although Y chromosome is essential for the fertility in male
drosophila, but it is inert and has nothing to do with the sex
determination
• Thus the balance between the female sex determining genes of X
chromosome and male sex determining genes autosomes
determine the sex in drosophila
• If ratio between X chromosome and set of autosome is 2:2 then
female sex
• If ratio between X chromosome and set of autosome is 1:2 then
male sex
12. Environmental sex determination in Bonellia
• External environment plays a key role in sex determination
• In Bonellia the males are ciliated and externally small with respect
to the females which are big in size
• Males lives as a parasite inside the body of female