Biology Chapter 11 - Genetics Test Review

Question 1

Are there any exceptions to Mendel’s principles? What are some examples?

Answer 1

Yes;

1. Some genes are neither dominant nor recessive
2. Many genes have multiple alleles
3. Many traits are produced by the interactions between several genes

Question 2

Describe the relationship between genes and the environment.

Answer 2

Genes provide a plan for development, but how that plan unfolds also depends on the environment. Environmental conditions affect gene expression.

Question 3

How many sets of genes do multicellular organisms inherit?

Answer 3

The diploid cells contain 2 copies of chromosomes and 2 sets of genes

Question 4

What are chromosomes?

Answer 4

Strands of protein and DNA inside the cell nucleus; the carriers of genes.

Question 5

What does ‘haploid’ mean? What are haploid cells?

Answer 5

Haploid = “one set”

Haploid cells = containing only one set of chromosomes and one set of cells

Question 6

What are the main phases of meiosis? (There are 5)

Answer 6

1. Prophase I
2. Metaphase I
3. Anaphase I
4. Telophase I
5. Prophase II

Question 7

What happens in Prophase I ?

Answer 7

Each replicated chromosome pairs with its corresponding homologous chromosome.

Question 8

What happens in Metaphase I ?

Answer 8

Paired homologous chromosomes line up across the center of the cell.

Question 9

What happens in Anaphase I ?

Answer 9

Spindle fibers pull each homologous chromosome pair toward opposite ends of the cell.

Question 10

What happens in Telophase I ?

Answer 10

A nuclear membrane forms around each cluster of chromosomes. Cytokinesis follows this phase and produces two new cells.

Question 11

What happens in Prophase II ?

Answer 11

The cells’ chromosomes (each consisting of two chromatids) become visible.

Question 12

The final four stages of Meiosis II result in what kind of cells?

Answer 12

Four haploid daughter cells.

Question 13

What happens in Prophase I ?

Answer 13

Each replicated chromosome pairs with its corresponding homologous chromosome. Tetrads form. Homologous chromosomes pair up and undergo crossing-over.

Question 14

What happens in Metaphase I ?

Answer 14

Paired homologous chromosomes line up across the center of the cell. Spindle forms and attaches itself to a tetrad.

Question 15

What happens in Anaphase I ?

Answer 15

Spindle fibers pull each homologous chromosome pair toward opposite ends of the cell. After anaphase, the separated chromosomes cluster at opposite end of the cell.

Question 16

What happens in Prophase II ?

Answer 16

The cells’ chromosomes (each consisting of two chromatids) become visible.

Question 17

What does Meiosis I result in?

Answer 17

2 daughter cells that each have 4 chromatids

Question 18

What stages occur in Meiosis II ?

Answer 18

Prophase II
Metaphase II
Anaphase II
Telophase II
Cytokinesis

Question 19

What happens in Prophase II ?

Answer 19

Chromosomes (which each have 2 chromatids) become visible.

Question 20

What happens in Metaphase II ?

Answer 20

Chromosomes line up at the center of the cell

Question 21

What happens in Anaphase II ?

Answer 21

Paired chromatids separate

Question 22

The ____ cells produced by meiosis II are gametes.

Answer 22

Haploid. (Four haploid daughter)

Question 23

Fertilization generates new combinations of alleles in ___.

Answer 23

a zygote

Question 24

How is meiosis different from mitosis?

Answer 24

Mitosis does not change number of chromosomes of the original cell. Meiosis reduces the number of chromosomes by half.

In mitosis, two sets of genetic material separate and each daughter cell receives one set of chromosomes. In Meiosis, homologous chromosomes line up and then move to separate daughter cells.

Mitosis results in the production of two genetically identical diploid cells whereas meiosis produces four genetically different haploid cells.