Chapter 20 Pt. 1

Question 1

What is a gene?

Answer 1

directs the synthesis of a specific protein that can play either a structural or a functional role in the cell

Question 2

What are alleles?

Answer 2

different versions of a gene

Question 3

________ produce different versions of the trait they determine

Answer 3

alleles

Question 4

What is the difference between homozygous and heterozygous alleles?

Answer 4

homozygous-individuals with two copies of the same allele of a gene

heterozygous- individuals with different alleles of a given gene

Question 5

homozygous:
homo=______
zygo= _______ ________

Answer 5

same

joined together

Question 6

heterozygous:
hetero=_________
zygo= ________ _________

Answer 6

different

joined together

Question 7

What is the difference between dominant and recessive alleles?

Answer 7

dominant allele- when the effects of a certain allele can be detected regardless of whether an alternative allele is also present

recessive allele- an allele whose effects are masked in the heterozygous condition

Question 8

What are the designated signs for dominant and recessive alleles?

Answer 8

dominant allele-capital letter

recessive allele-lowercase letter

Question 9

What is a genotype?

Answer 9

the precise set of alleles a person possesses for a given trait or traits

Question 10

The ________ tells us whether the individual is homozygous or heterozygous for a given gene

Answer 10

genotype

Question 11

The genotype tells us whether the individual is ___________ or ____________ for a given gene

Answer 11

homozygous

heterozygous

Question 12

What is a phenotype?

Answer 12

the observable physical trait or traits of an individual

Question 13

What is the law of segregation?

Answer 13

during the production of gametes the two copies of each hereditary factor segregate so that offspring acquire one factor from each parent

Question 14

The ____ ___ ___________, explains how, for every gene in our chromosomes, one of the alleles comes from our mother, and one comes from our father

Answer 14

law of segregation

Question 15

What is the law of independent assortment?

Answer 15

when two or more characteristics are inherited individual hereditary factors assort independently during gamete production, giving different traits an equal opportunity of occurring together

Question 16

The ____ __ ____________ __________, explains why the mixture of alleles that came from the mother, and alleles that came from the father, is different in every gamete

Answer 16

law of independent assortment

Question 17

_______ _______ is a monk, whose ideas are used today to predict the outcome of hereditary crosses

Answer 17

Gregor Mendel

Question 18

What is a one-trait crosses?

Answer 18

consider the inheritance of a single trait

Question 19

What is a Pungent Square?

Answer 19

a diagram used to predict the genetic makeup of the offspring of individuals of particular genotypes

Question 20

What does a Pungent Square diagram look like?

Answer 20

columns are set up and labeled to represent each of the possible gametes of one parents

Question 21

What are two-trait crosses?

Answer 21

predict the probable outcome for inheritance of two traits of interest

Question 22

What is a dihybrid cross?

Answer 22

a mating of individuals who are both heterozygous for two traits of interest