Biology chapter 11

1-Organisms that have two identical alleles for a particular trait are said to be

homozygous

2-The chemical factors that determine traits are called

genes

3-A male and female bison that are both heterozygous for normal skin pigmentation (Aa) produce an albino offspring (aa). Which of Mendel’s Principles explain(s) why the offspring is albino?

d-dominance and segregation

4-Gametes have

one allele for each gene

5-Gregor Mendel’s principles of genetics apply to

d-all organisms

6-What principle states that during gamete formation genes for different traits separate without influencing each other’s inheritance?

b-principle of independent assortment

7-If a pea plant has a recessive allele for green peas, it will produce

a-green peas if it does not also have a dominant allele for yellow peas

8-A cross of a black chicken (BB) with a white chicken (WW) produces all speckled offspring (BBWW). This type of inheritance is known as

d-codominance

9-If a pea plant that is heterozygous for round, yellow peas (RrYy) is crossed with a pea plant that is homozygous for round peas but heterozygous for yellow peas (RRYy), how many different phenotypes are their offspring expected to show?

2

10-A tall plant is crossed with a short plant. If the tall F1 pea plants are allowed to self-pollinate,

b-some of the offspring will be tall, and some will be short

11-In the P generation, a tall plant is crossed with a short plant. Short plants reappeared in the F2 generation because

the allele for shortness and the allele for tallness segregated when the F1 plants produced gametes

12-Offspring that result from crosses between parents with different traits

are called hybrids

13-What percentage of human sperm cells carry an A chromosome?

50%

14-Gregor Mendel concluded that traits are

inherited through the passing of factors from parents to offspring

15-In the Punnett square shown in figure 11-1, which of the following is true about the offspring resulting from the cross?

about half are expected to be short

16-How many different allele combinations would be found in the gametes produced by a pea plant whose genotype was RrYY?

2

17-Gregor Mendel used pea plants to study

the inheritance of traits

18-When you flip a coin, what is the probability that it will come up tails?

d-1/2

19-A heterozygous tall pea plant is crossed with a short plant. The probability that an F1 plant will be tall is

50%

20-A Punnett square shows all of the following EXCEPT

d-the actual results of a genetic cross

21-The principles of probability can be used to

b-predict the traits of the offspring produced by genetic crosses

22-When Gregor Mendel crossed true-breeding tall plants with true-breeding short plants, all of the offspring were tall because

c-the allele for tall plants in dominant

23-Variation in human skin color is an example of

polygenic traits

24-When Gregor Mendel crossed a tall plant with a short plant, the F1 plants inherited

an allele for tallness from the tall parent and an allele for shortness from the short parent

25- If you made a Punnett square showing Gregor Mendel’s cross between true-breeding tall plants and true breeding short plants, the square would show that the offspring had

b-a genotype that was different from that of both parents

26- Situations in which one allele for a gene is not completely dominant over another allele for that gene are called

-incomplete dominance

27-The principle of dominance states that

b-some alleles are dominant and others are recessive

28-Why did Thomas Hunt Morgan use fruit flies in his studies?

c-fruit Flies produce a large number of offspring

29-A heterozygous male guinea pig with black, rough hair is crossed with a heterozygous black, rough haired female. B-black; b-white; R-rough; r-smooth. Show the Punnett Square and give the phenotypic ratios of the traits for the offspring.

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