Biology - Chapter 6 review

3. How many egg cells form from a female germ cell?

1

3. What offspring are predicted from a Bb x bbcross? A. all Bb B. all bb C. 50% Bb and 50% bb D. 75% Bb and 25% bb

50% Bb and 50% bb

5. Which is Mendel's law of independent assortment? A. Allele pairs separate independently during meiosis. B. Allele pairs separate independently during mitosis. C. Different allele pairs are inherited together. D. Different alleles of the same gene are found at the same locus.

Allele pairs separate independently during meiosis.

2. How are a gene and an allele related? A. An allele is an alternative form of a gene. B. A gene is an alternative form of an allele. C. A gene has many loci, called alleles. D. An allele is made up of many structures, called genes.

An allele is an alternative form of a gene.

2. Why does the number of possible chromosome combinations vary by species? A. Homologous chromosomes pair up differently in different species. B. Crossing over occurs in some species but not in others. C. Not all species form gametes by meiosis. D. Different species have different numbers of chromosomes.

Different species have different numbers of chromosomes.

________ cells, have two copies of each chromosome: one from the mother & one from the father.

Diploid

Process of meiosis

During meiosis, diploid cells undergo two cell divisions that result in haploid cells. In meiosis I, homologous chromosomes pair up along the cell equator and are divided into separate cells. In meiosis II, sister chromatids are divided into separate cells, making a total of four haploid cells that are genetically unique.​

4. Which of the following is a testcross? A. FF x Ff B. Ff x Ff C. Ff x ff D. FF x FF

Ff x FF

Chromosomes and meiosis

Gametes have half the number of chromosomes that body cells have. Your body cells have 23 pairs of homologous chromosomes, making 46 total chromosomes. Gametes have only 1 chromosome from each homologous pair—23 chromosomes in all.

Traits, genes, & alleles

Genes encode proteins that produce a diverse range of traits. Every diploid organism has two alleles for each gene: one from the mother, one from the father. These two alleles may be the same (homozygous) or different (heterozygous). One allele may be dominant over another.​

Gametes, or ___________ cells, have only one copy of each chromosome.

Haploid cells

1. Which is a cause of genetic variation during meiosis? A. Homologous chromosomes pair up randomly during meiosis I. B. Homologous chromosomes pair up randomly during meiosis II. C. Homologous chromosomes pair up randomly during mitosis I. D. Homologous chromosomes pair up randomly during mitosis II.

Homologous chromosomes pair up randomly during meiosis I.

Meiosis & genetic Variation

Independent assortment and crossing over during meiosis result in genetic diversity. Independent assortment produces unique combinations of parental chromosomes. Crossing over between homologous chromosomes creates a patchwork of genes from both parents. Genetic linkage describes genes that are close together and tend to be inherited as a unit.​

4. A purebred tall plant is crossed with a purebred short plant. All the F1 offspring are tall. What can you say about the allele for tallness? A. It is recessive. B. It is homozygous. C. It is dominant. D. It is heterozygous.

It is dominant.

The form of nuclear division that divides a diploid cell into haploid cells is called...

Meiosis

Mendel and Heredity

Mendel's research showed that traits are inherited as discrete units. His large amount of data, control over breeding, use of purebred plants, and observation of "either-or" traits allowed him to see patterns in the inheritance of traits. He concluded that organisms inherit two copies of each gene and that organisms donate only one copy of each gene in their gametes.​

During which phase of meiosis does the cell undergo cytokineses?

Telophase I

Traits & probability

The inheritance of traits follows the rules of probability. Punnett squares are a grid system for predicting all possible genotypes resulting from a cross. When Mendel performed two-trait crosses, he discovered that different traits appear to be inherited separately—the law of independent assortment. The patterns of inheritance that he observed can be predicted by using mathematical probabilities.​

5. What can you say about two genes that are linked? A. They are on different chromosomes. B. They are close together on a chromosome. C. They are at opposite ends of the same chromosome. D. They will be inherited independently.

They are close together on a chromosome.

2. Which of the following correctly represents a dihybrid cross? A. aabb x AaBb B. ab x Ab C. aa x Aa D. aabbcc x AaBbcc

aabb x AaBb

1. What resulted when Mendel crossed a purple-flowered plant with a white-flowered plant? A. Some offspring had purple flowers and some had white flowers. B. All the offspring had white flowers. C. All the offspring had purple flowers. D. All the offspring had pink flowers.

all of the offspring had purple flowers

2. In what phase of meiosis are homologous chromosomes separated?

anaphase I

1. In what phase of meiosis are sister chromatids separated?

anaphase II

3. What was the advantage of Mendel's working with purebred plants? A. Any variations in offspring had to be caused by the experiment. B. Purebred plants were more readily available. C. Purebred plants were easier to grow. D. Only purebred plants could be self-pollinated.

any variations in offspring had to be caused by the experiments

3. What term describes chromosomes that exist in cells as homologous pairs?

autosomes

4. What resulted when Mendel crossed two purple-flowered plants from an F1 generation? A. All the offspring had purple flowers. B. Both purple-flowered plants and white-flowered plants appeared in a 3:1 ratio. C. All the offspring had white flowers. D. Both purple-flowered plants and white-flowered plants appeared in a 1:1 ratio.

both purple-flowered plants & white-flowered plants appeared in a 3:1 ratio

3. What term describes the exchange of chromosome segments during prophase I? A. genetic linkage B. independent assortment C. crossing over D. meiosis.

crossing over

Which of the following cells is haploid? A. nerve cell B. gamete C. skin cell D. muscle cell

gamete

4. In what kind of cell does crossing over occur? A. germ cell B. blood cell C. egg cell D. sperm cell

germ cell

If the genotype of a plant is Cc, it is...

heterozygous

5. Which of the following is not one of Mendel's conclusions? A. Traits are inherited as discrete units. B. Homologous chromosomes pair up and then separate during meiosis. C. Organisms inherit two copies of each gene, one from each parent. D. Organisms donate only one copy of each gene in their gametes.

homologous chromosomes pair up & then separate during meiosis

1. What term describes a person who has two identical alleles at a specific locus? A. homozygous B. heterozygous C. homozygous dominant D. homozygous recessive

homozygous

2. Where are germ cells found in the human body?

in the ovaries & testes

2. Which of the following did not play an important role in developing Mendel's conclusions? A. control over the breeding of pea plants B. leaf structure in pea plants C. use of purebred plants D. observation of "either-or" traits that appeared in only two forms

leaf structure in pea plants

1. What process produces gametes?

meiosis

5. Which statement describes meiosis? A. Meiosis produces genetically identical cells. B. Meiosis results in haploid cells. C. Meiosis takes place throughout an organism's life. D. Meiosis is involved in asexual reproduction..

meiosis results in haploid cells

3. What term describes the physical traits of a person? A. genotype B. phenotype C. genome D. dominant

phenotype

5. Which of the following represents a homozygous recessive genotype? A. Rr B. RR C. rR D. rr

rr

5. What are polar bodies?

the cells formed by meiosis in females that are broken down

1. What do the grid boxes in a Punnett square represent? A. the possible gamete genotypes of each parent B. the possible genotypes of offspring from two parents C. the number of offspring these parents will have D. the possible phenotypes of offspring from two parents

the possible genotypes of offspring from two parents

4. What does gametogenesis mean?

the production of eggs & sperm.