Bio Chap 12

What is a genotype?

The underlying genetic make up, consisting of physically visible and non-expressed alleles

What is a phenotype?

Observable traits expressed by an organism

What is the difference in a genotype and phenotype?

Genotypes are genetic makeup and phenotypes are the observable trait

What is the relationship between phenotype and genotype?

The phenotype is the result of the genotype being expressed

Example of a genotype in eye color?

BB, Bb, and bb

Example of a Phenotype in eye color?

BB or Bb is brown eyes ,bb is blue eyes

Example of a genotype in tongue rolling?

RR, Rr,rr

Example of a phenotype in tongue rolling?

RR and Rr can roll tongue ,rr can't roll tongue

What are x-linked traits?

Traits controlled by genes , located on x chromosome

How many X chromosomes so males have?

One

How many X chromosomes do females have?

2

What does heterozygous mean?

Having 2 different alleles for a given gene on the homologous chromosome

What is a homozygous?

Having 2 identical alleles for a given gene on the homologous chromosome

What is the difference in types when talking about homozygous and heterozygous?

Homozygous have either dominant or recessive where as heterozygous has one dominant and one recessive

What is a haploid cell?

Cell with one set of chromosomes, found in gametes

What is a diploid cell?

Cell with 2 sets of chromosomes, found in somatic cells

What is the result of a Cross between two tru-breeding parents that express different traits for two characteristics?

Dihybrid crossing

What is the result of a Cross between two true-breeding parents that express different traits for only one characteristic?

Monohybrid crossing

When are dominant alleles expressed?

Expressed whenever present

When are recessive alleles expressed?

Only expressed if no dominant allele is present

What is a test cross?

Is used to determine the genotype of an organism showing a dominant phenotype

What are you trying to figure out with a test cross?

If its homozygous dominant or heterozygous

What is a sex link?

Any gene on a sex chromosome

What is pleiotrophy?

One single gene affects multiple traits in an organism

How does pleiotrophy work?

A gene makes a protein That's used in different parts of the body pieiotropry

What sickness is an example of pleiotrophy?

Sickle cell disease

What is sickle cell disease?

Abnormal red blood cell shapes

What is epitasis?

One gene masks or controls the expression of another gene

what is a allele?

Gene variations caused by mutation

What are any of the non-sex chromosomes?

Autosomes

What is codominance in a heterozygote?

Complete and simutaneous expression of both alleles for the same characteristic

What is the filial generation in a cross; the offspring of the parental generation?

F1

What is the second filial generation Produced when F1 individuals are self-crossed with each other?

F2

What is a trait?

Variation in the physical appearance of a heritable characteristic

What is a gene present on the x , but not on the Y chromosome?

X-linked

What is the law of dominance in a heterozygote?

One trait will conceal the presence of another trait for the samecharacteristic

What is it when alleles are located close to each other on the same chromosome?

Linkage

What is the visual representation of a cross between two individuals ?

Punnet squares

What is the probability of the occurrence of at least one of two mutually exclusive events is the sum of their individual probabilities?

Sum rule

What is a reciprocal Cross?

You perform the same genetic Cross but swap the sexes of the parents

What is incomplete dominance in a heterozygote?

Expression of 2 contrasting alleles such that the individual shows an intermediate phenotype

What is the law of