Chapter 10 Review

Meiosis and Mendelian Genetics

Define: meiosis

A type of cell division that produces gametes; reduces

chromosome number by half

Define: zygote

The cell produced when a male sperm and female egg fuse

Define: haploid

A cell that contains one member of each chromosome pair

Define: heredity

The passing of characteristics from parents to offspring

Meiosis results in the formation of …

4 genetically different haploid cells

The gamete that contains genes contributed only by the mother is

the … Egg

The typical human body cell contains 46 chromosomes. How

many chromosomes would a typical human sperm cell have?

23

What process is shown in this figure?

• Crossing over

Consider the cell labeled X in Figure 10-9 containing 4 chromosomes. Which of the four cells below it represents a healthy gamete that could be

produced from this cell?

• A

Which stage of meiosis is represented in this figure?

• Metaphase 1

In this figure, which set of chromatids illustrates the result of a single crossover of

the homologous chromosomes?

• A

Describe the events of anaphase II

Sister chromatids are separated and pulled to opposite sides of the

cell (poles)

What is the role of the spindle fibers?

To move chromosomes in the cell

The numbers in Figure 10-1 represent the chromosome number found in each of the dog

cells shown. The processes that are occurring at A and B are ____.

• a. mitosis and fertilization• b. mitosis and pollination• c. meiosis and fertilization• d. meiosis and pollination

A useful device for predicting the possible offspring of crosses

between different genotypes is called a …

Punnett square

A white mouse whose parents are both white produces only brown offspring when mated with

a brown mouse. The white mouse is most probably ____.

Homozygous recessive

In chickens, rose comb (R) is dominant to single comb (r). A homozygous rose-combed rooster is mated with a single-combed hen. All of the

chicks in the F1 generation were kept together as a group for several years. They were allowed to mate only within their own group. What is the

expected phenotype of the F2 chicks?

75% rose comb & 25 % single comb

In mink, brown fur color is dominant to silver-blue fur color. If a homozygous brown mink is mated with a silver-blue mink and 8 offspring

are produced, how many would be expected to be silver-blue?

0

What fraction of this cross will be recessive for both traits?

• 1/16

A true-breeding tall pea plant is crossed with a true-breeding short pea plant, and all the offspring are tall. What is the most likely

genotype of the offspring assuming a single-gene trait?

Tt

In mice, black is dominant to white color and color is determined by a single gene. Two black

mice are crossed. They produce 2 black offspring and one white offspring. If the white

offspring is crossed with one of its parents, what percent of the offspring are expected to be

white?

50

A heterozygous organism is best described as which of these?

A. Hybrid B. PhenotypeC. True BreedD. Genotype

In which situation are the phenotypes of F2 offspring expected to follow the ratio of 9:3:3:1.

a. a monohybrid cross for 2 unlinked traitsb. a monohybrid cross for 2 closely linked

traitsc. a dihybrid cross for 2 unlinked traits

d. a dihybrid cross for 2 closely linked traits

Which of the following describes an organism that has the

genotype Bb?

a. homozygousb. inbreedc. heterozygous d. all of these

The statement: "In meiosis, the way in which a chromosome pair separates does not affect the

way other pairs separate," is another way of expressing Mendel's law of _____.

a. dominanceb. independent assortmentc. first filial generationsd. Punnett squares

Genes located on homologous chromosomes may have alternate forms that control different

forms of a trait. These alternate forms of a gene are called _____.

a. allelesb. phenotypesc. centromeresd. gametes

A dog's phenotype can be determined by _____.

a. looking at the dog's parentsb. examining the dog's chromosomesc. mating the dog and examining its

offspringd. looking at the dog