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BIOL239 Lecture Notes - Lecture 2: Probability Distribution, Siamese Cat, Lentil

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2 Mar 2018

School

University of Waterloo

Department

Course

Professor

Christine Dupont

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Document Summary

Polygenic: traits that are controlled by two or more genes. A polygenic refers to a group of genes that when expressed together produce a particular phenotype or trait. Multiple genes are involved for a particular trait to manifest. In humans, height, skin colour, and weight are determined by multiple genes that are expressed together. Polygenes allow a wide range of physical traits. For instance, height is regulated by several genes so that there will be a wide range of heights in a population. Multifactorial: that is determined by two or more genes and their interaction with the environment. Polygenic and multifactorial traits are known as complex traits. Incomplete dominance: is a form of intermediate inheritance in which one allele for a specific trait is not completely expressed over its paired allele. This results in a third phenotype in which the expressed physical trait is a combination of the phenotypes of both alleles.

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Related Questions

answer to: matching:

Complete Dominance________

Genomic Imprinting_________

Incomplete Dominance________

Co-dominance __________

Polygenic trait___________

Lethal allele______________

Pleiotropy_____________

Penetrance___________

Sex-limited trait_________

Sex-influenced trait________

Anticipation ____________

Expressivity ____________

A. Heterozygotes have phenotypes intermediate between the phenotypes of the two homozygotes.

B. The heterozygote simultaneously expresses the phenotypes of both homozygotes.

C. Causes death at an early stage of development so that some genotypes do not appear among the progeny.

D. The percentage of individuals having a particular phenotype that exhibit the expected phenotype.

E. The phenotype of the heterozygote is the same as the phenotype of one of the homozygotes.

F. A trait determined by an autosomal gene that is more easily expressed in one sex

G. A trait determined by an autosomal gene that is expressed in only one sex

H. A trait determined by genes at many loci

I. The expression of a trait is affected by the sex of the parent that transmits the gene to the offspring

J. The trait appears earlier or more severely in succeeding generations

K. Degree to which a trait is expressed

L. A gene affects more than one phenotype

Jim is blood type A, his brother John is type O and his sister Jane is type AB. What are the genotypes of their parents?

Which of the following is true for alleles that show incomplete dominance?

Heterozygotes have a genotype like the dominant allele.

Homozygotes have a genotype like the recessive allele.

Heterozygotes have a phenotype intermediate between the dominant and recessive alleles.

Homozygotes have the same phenotype as the heterozygotes.

Which principle of inheritance concluded that when games are formed in meiosis, the two alleles of each gene separate from one another, and each gamete receives only one allele?

independent assortment

Which term best describes a condition in which alleles at one locus can alter the expression of alleles at another locus?

polygenic inheritance

multiple alleles

A single unit of genetic information located on a chromosome defines:

The physical expression (appearance or function) of an organism's genes defines:

a single characteristic

Palomino horses (golden color with a blond mane) are an incompletely dominant trait produced by the combination of the chestnut color allele and the cream color allele. If you wanted to produce as many palominos as possible, which mating strategy below would be the best choice?

Chestnut x Cream

Palomino x Cream

Palomino x Chestnut

Palomino x Palomino

Which term best describes the effect of a single gene on multiple aspects of the phenotype?

multiple alleles

polygenic inheritance

Which term best describes the separate expression of both alleles for a single trait in the same cell?

multiple alleles

polygenic inheritance

One form of a gene found on a single chromosome defines:

A chocolate lab (whose mother was a yellow lab) is mated with a black lab whose genotype is BbEe. What fraction of the offspring would be expected to be yellow labs?

What type of allele is always expressed regardless of whether the individual is homozygous or heterozygous for it?

Both the dominant and recessive alleles

Recessive allele

Allosteric allele

Dominant allele

Given the parents AABBGgHhrr Ã AabbGgHhRr, assume simple dominance and independent assortment. What proportion of the progeny will be expected to have the genotype AaBbggHHrr?

___________________ is defined as having two of the same type of allele for a particular trait.

Incomplete dominance

The physical position of an allele on a single chromosome defines:

Which term best describes two or more genes affecting the phenotype in an additive fashion?

polygenic inheritance

multiple alleles

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1.) Alterations in chromosome number can occur with any chromosome, but most alterations are not seen in human populations because:

A) the phenotype is homozygous recessive.

B) the phenotype is expressed in a continuous range in a given population and thus does not stand out.

C) they are lethal during fetal development.

D) most are corrected during the first mitotic event in the fertilized egg.

E) the genotype still represents a normal condition.

2.) Polygenic traits display phenotypes that

A) are most commonly reflective of the heterozygous condition.

B) usually express the dominate condition in greater than 75% of the population.

C) represent a continuous range within the population.

D) often are lethal to second generation of children.

E) are masked by a codominance condition.

3.) Which of the following is most likely involved in the determination of intelligence?

A) one gene

B) multiple genes

C) the environment

D) one gene and the environment

E) multiple genes and the environment