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Basic Aquaculture Genetics
Basic Aquaculture Genetics

... generation is called gametogenesis. More specifically, the production of sperm cells is referred to as spermatogenesis, while the production of egg cells is called oogenesis. In meiosis, at least three important processes occur to produce genetic variability in the sperm and egg: crossing over, segr ...
Lecture PPT - Carol Eunmi LEE
Lecture PPT - Carol Eunmi LEE

... • Organisms that reproduce early in life are the ones that age faster ...
Examining Intraspecies Variation and Changes in a Single Horse
Examining Intraspecies Variation and Changes in a Single Horse

... After the students take measurements on the image set, the authors suggest that this would also be a good time for students to have direct instruction on natural selection. The major ideas are as follows: 1) Populations produce more offspring than can survive. Individuals in the population are NOT ...
Chapter 11
Chapter 11

...  A couple has a child with type O blood. If one parent is type O, what are the possible genotypes of the other parent? ...
W i
W i

... Why is sex ratio about even (1:1) in many species of animals? This is quite a puzzle: • From a group-selectionist perspective we might expect that a female-biased sex ratio would be advantageous because such a population could grow more rapidly • From a individual selection perspective why should a ...
The Principle of Segregation
The Principle of Segregation

... • The two alleles that make up each gene may be the same or different. • If the alleles are the same they are called homozygous • If the alleles are different they are called heterozygous ...
A 15-Myr-Old Genetic Bottleneck - University of California San Diego
A 15-Myr-Old Genetic Bottleneck - University of California San Diego

... polymorphism. First, dozens of alleles occur in natural populations with alleles accumulating until a balance is reached between selection favoring rarity and drift causing allele loss (Wright 1939; Lawrence 2000). Second, alleles are often very old because, if any allele drifts toward rarity, selec ...
The Founder Effect and Deleterious Genes - Deep Blue
The Founder Effect and Deleterious Genes - Deep Blue

... the population is closed. Gene flow from other populations would tend to decrease the frequency of the deleterious gene, but if most of the population’s expansion is due to natural increase, then the founder effect would be most important. In order to determine whether such high frequencies could oc ...
(lectures 24
(lectures 24

... to their relatives) . This may be owing to problems with sex-determination in XXYY individuals and owing to not being able to self-fertilize. 29. There are thought to have been at least two genome doublings in the lineage from the origin of vertebrates to us. 30. Angiosperm plants often have groups ...
Biology 22: Genetics and Molecular Biology
Biology 22: Genetics and Molecular Biology

... For Jack and Jill, what is the probability that the first child will have PKU, the second child will not have PKU and the third child will have ...
1-Intro to genetics - Science-with
1-Intro to genetics - Science-with

... • even though the F1 generation had a copy of both genes only one was expressed. • Mendel called this characteristic dominant. allele: one of alternative forms of a gene. the gene for wrinkled and the gene for round peas are alleles. ...
Andrews 1999 Corrected CRS.NatGen
Andrews 1999 Corrected CRS.NatGen

... The assignment of the revised CRS to haplogroup H is confirmed by the absence of any of the predicted restriction site changes that characterize the other European mtDNA haplogroups4,6. If we include both the technical errors (8) and the errors (3) introduced by the assumption of the bovine and HeLa ...
D. 100% dominant
D. 100% dominant

Chromosome Theory of Inheritance -States that genes or alleles
Chromosome Theory of Inheritance -States that genes or alleles

... Polyploidy-Multiple Chromosome Alterations ...
flipperiuabstract
flipperiuabstract

PowerPoint lecture - Lower Cape May Regional School District
PowerPoint lecture - Lower Cape May Regional School District

... • With an autosomal recessive inheritance pattern, only persons who are homozygous for an allele have the associated trait, which can skip generations ...
One Pair of Contrasting Traits
One Pair of Contrasting Traits

... •Traits Influenced by Several Genes Many traits— weight, hair color, and skin color—are polygenic traits that involve several genes influencing the trait. •Intermediate Traits A trait that is intermediate between the two parental types is a condition known as incomplete dominance. •Traits Controlled ...
Chapter 12
Chapter 12

... heterozygous or homozygous dominant for an autosomal gene, their phentoype will show the dominant trait.  Homozygous recessive shows the recessive trait.  If a child shows the recessive trait, that means that both parents are heterozygous carriers of the recessive allele. ...
Ch 23 Evolution of Populations - juan-roldan
Ch 23 Evolution of Populations - juan-roldan

... • How do female preferences evolve? • The good genes hypothesis suggests that if a trait is related to male health, both the male trait and female preference for that trait should be selected for. ...
Patterns of Inheritance
Patterns of Inheritance

... • Many genes have multiple alleles, instead of just two – Ex: human blood type – A, B, AB, O – IA and IB display codominance, meaning that a heterozygote expresses both traits – This is NOT intermediate, due to the fact that the phenotype shows the separate traits of both alleles ...
EVOLUTION
EVOLUTION

... the liability level corresponds to a switchlike reaction norm and thus implies high sensitivity to an external environmental factor at the level of the sex ratio probabilities. This is somewhat different from the idea of canalization of morphological traits with a unimodal distribution, where develo ...
Learning Objectives and Outcomes
Learning Objectives and Outcomes

... DNA  Genes  Charles Darwin  Selective Breeding  Evolution  Natural Selection  Sexual Selection  Nature-Nurture? LO = What are the key features of the biological approach? ...
The Hardy-Weinberg Equation
The Hardy-Weinberg Equation

File
File

... together because they pass into the gamete, and hence the offspring, together. • During meiosis, at least one chiasma forms between two homologous chromosomes. However, it may not form between a particular pair of genes. The further apart the genes are, the more likely it is that crossing over will ...
Maintenance of genetic diversity: challenges for management of
Maintenance of genetic diversity: challenges for management of

... New animals may migrate from one population to another, and if they mate within the new population, they have the potential to contribute new alleles to the local gene pool. This is called gene flow. There are many theoretical types of genetic population structure (cf. Smedbol et al., 2002); these r ...
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Polymorphism (biology)



Polymorphism in biology is said to occur when two or more clearly different phenotypes exist in the same population of a species—in other words, the occurrence of more than one form or morph. In order to be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating).Polymorphism as described here involves morphs of the phenotype. The term is also used somewhat differently by molecular biologists to describe certain point mutations in the genotype, such as SNPs (see also RFLPs). This usage is not discussed in this article.Polymorphism is common in nature; it is related to biodiversity, genetic variation and adaptation; it usually functions to retain variety of form in a population living in a varied environment. The most common example is sexual dimorphism, which occurs in many organisms. Other examples are mimetic forms of butterflies (see mimicry), and human hemoglobin and blood types.According to the theory of evolution, polymorphism results from evolutionary processes, as does any aspect of a species. It is heritable and is modified by natural selection. In polyphenism, an individual's genetic make-up allows for different morphs, and the switch mechanism that determines which morph is shown is environmental. In genetic polymorphism, the genetic make-up determines the morph. Ants exhibit both types in a single population.Polymorphism also refers to the occurrence of structurally and functionally more than two different types of individuals, called zooids within the same organism. It is a characteristic feature of Cnidarians.For example, in Obelia there are feeding individuals, the gastrozooids; the individuals capable of asexual reproduction only, the gonozooids, blastostyles and free-living or sexually reproducing individuals, the medusae.
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