CH 9 BIO

Fertilization is the fusion of a(n) blank cell and a(n) blank cell to form a diploid zygote.

egg, sperm

During anaphase of meiosis I BLANK chromosomes separate, whereas during anaphase of meiosis II BLANK chromatids are separated.

homologous sister

If a sperm cell containing 12 chromosomes from the male parent fused with an egg from the female parent, how many total chromosomes would be present in a diploid zygote?

24

If a parent cell contained six chromosomes, how many chromosomes would be present in a haploid gamete produced by the cell?

3

If an organism has three homologous pairs of chromosomes, how many different orientations of chromosomes on the metaphase plate are possible?

8

fission of prokaryotes is an example of asexual reproduction

Binary

fission of prokaryotes is an example of asexual reproduction.

Binary

How does meiosis I differ from meiosis II? Select all that apply.

in meiosis I, homologous chromosomes separate in meiosis II, sister chromatids separate

Three mechanisms that make key contributions to generate new genetic combinations are

independent assortment, crossing over, and random fertilization.

A somatic cell of an adult male has 46 chromosomes. The number of chromosomes in his sperm cells would be

23

animal protist plant

1 almost all are diploid 2 haploid 3 spend nearly equal portions

synapsis corssing over

1. homo chromo align 2. homo chromo exchange

Place the phases of meiosis in the correct order starting with the first phase at the top.

1. pro 2. meta 3. ana 4. telo

The fusion of gametes to form a new cell is called

fertilization

The final result of meiosis II is

four haploid cells.

At the end of meiosis ______ genetically ______, ______ cells are produced.

four; distinct; haploid

Diploid, gamete-forming cells located in reproductive organs are referred to as blank -line cells.

germ

What is a key evolutionary consequence of sexual reproduction?

increases genetic diversity

Exchanging DNA during crossing over

increases the possible genetic combinations that can occur among gametes.

Exchanging DNA during crossing over Multiple choice question.

increases the possible genetic combinations that can occur among gametes.

The random orientation of chromosomes on the metaphase plate that results in gametes with different combinations of parental chromosomes is called ______.

independent assortment

Which of the following occur only during meiosis I?

independent assortment homologous pairs separate crossing over

Three mechanisms that make key contributions to generate new genetic combinations are Multiple choice question.

independent assortment, crossing over, and random fertilization.

In meiosis the replication of chromosomes occurs during ______.

interphase

What process in meiosis is responsible for the production of daughter cells with half as many chromosomes as the parent cell?

reduction division

Select the two unique features that distinguish meiosis from mitosis.

reduction division synapsis

What occurs during interphase that precedes meiosis?

replication of chromosomes

Reproduction that involves alternating meiosis and fertilization is called _____ reproduction.

sexual

The alternation between diploid chromosome numbers and haploid chromosome numbers (alternation of generations) is the key characteristic of the ______.

sexual life cycle

1 gametes 2 zygote 3 fertilization

1 egg and sperm 2 the product of fusion of an egg and sperm 3 fusion of gametes to form a new cell

anaphase of mitosis anaphase 1 anaphase 2

1, identical sister 2. homo 3 sister chromatids

prophase 2 meta 2 ana 2 telo 2

1. chromosomes 2.chromosomes line 3. sister 4. the nuclear

meiosis 1 meiosis 2

1. homo 2 sister

prophase 1 meteaphase 1 anaphase 1 telophase 1

1. the two 2. homologous 3. homologues with 4. individual

What symbol represents a diploid cell?

1n

What meiotic division is most similar to mitosis?

2

The BLANK exchange that occurs when the arms of non-sister chromatids cross over adds more recombination.

DNA, genetic, or deoxyribonucleic acid

True or false: At some point in a somatic cell's life cycle, it will be temporarily haploid.

False

Which of the following best describes meiosis II?

Follows similar pattern as mitosis, without chromosomes replicating beforehand and sister chromatid separating during anaphase II.

is a process that results in the formation of gametes that have different combinations of parental chromosomes. This is partially due to random alignment of chromosomes along the metaphase plate during metaphase I.

Independent or independent assortment

What is the significance of meiosis?

Meiosis reduces the number of chromosomes to ensure a consistent number from one generation to the next.

Select the true statements about meiosis.

Microtubules can only attach to one side of each homologous chromosome during meiosis I. During prophase II, there is no crossing over.

How do you distinguish sexual reproduction from asexual reproduction?

Sexual reproduction involves the fusion of gametes from two parents.

Select all of the true statements distinguishing somatic and germ-line cells.

Somatic cells make up most of the organism and germ-line cells give rise to gametes. Both somatic and germ-line cell are diploid.

Select the statement below that is true of diploid cells.

Somatic cells that contain two sets of chromosomes.

How do somatic cells differ from germ-line cells?

Somatic cells undergo mitosis to produce identical diploid cells and germ-line cells undergo meiosis to produce haploid gametes.

What describes reduction division of meiosis?

The chromosome homologues do not replicate between the two nuclear divisions.

During meiotic division, chromosome number is reduced in gametes. Why is this important?

This ensures that the zygote has the correct number of chromosomes

Reproduction by mitotic division is called _____ reproduction.

asexual

Prokaryotes reproduce asexually through a process called

binary fission

Prokaryotes reproduce asexually through a process called

binary fission.

Select all of the following that describe somatic cells in animals.

body cells found in non-reproductive organs diploid

Select all the mechanisms that occur during sexual reproduction that make key contributions to generating diversity.

crossing over independent assortment random fertilization

Two sets of chromosomes are present in somatic cells of adult individuals, making them BLANK (2n) cells.

diploid

Somatic cells are ______.

diploid body cells found in animals

Select all of the following that are true about diploid cells.

diploid cells contain two sets of chromosomes somatic cells are diploid

Germ-line cells are best described as ______.

diploid cells that undergo meiosis to form sperm and egg

Somatic cells are BLANK because they have two sets of chromosomes, however gametes are BLANK because they only have one set of chromosomes.

diploid or diploid cells haploid or haploid cells

A cell taken from animal heart tissue would be ______, whereas an egg cell would be

diploid; haploid

A cell taken from animal heart tissue would be ______, whereas an egg cell would be ______.

diploid; haploid

What is the term that refers to the egg or sperm of an organism?

gamete

In sexually reproducing organisms egg and sperm are collectively referred to as

gametes

From his observations, Pierre-Joseph van Beneden discovered that cells called blank (eggs and sperm) each contained half the complement of chromosomes. When these cells fuse they produced a cell called a blank which contains the full complement of chromosomes.

gametes, zygote

Select all the characteristics of sexual reproduction.

generates genetic diversity promotes new traits in a changing environment

What type of cell is found in reproductive organs and undergoes meiosis to form gametes?

germ-line

At the end of telophase I, the cells are ______.

haploid

Select all of the following that are true about haploid cells.

haploid cells contain only one set of chromosomes gametes are haploid

A sperm cell from an animal would be ______, whereas its skin cell would be ______.

haploid; diploid

A type of cell division called BLANK reduces chromosome number, producing four haploid gametes; it ensures a consistent chromosome number from one generation to the next when gametes combine in fertilization.

meiosis

The process of ______ reduces chromosome number by half and results in four daughter cells.

meiosis

What type of cell division reduces the number of chromosomes and ensures a consistent number of chromosomes in offspring?

meiosis

Meiosis has two rounds of cell division called ______.

meiosis I and meiosis II

Select the two main divisions of meiosis.

meiosis II meiosis I

Select the four stages of meiosis I.

metaphase I telophase I anaphase I prophase I

The diagram shows four of the eight possible ways that three homologous pairs of chromosomes can align at the cell's central plane during ______. The random alignment of chromosomes during meiosis results in ______ and the production of gametes with different combinations of parental chromosomes.

metaphase I; independent assortment

During what meiotic II phase do spindle fibers bind to both sides of the centromeres and the chromosomes line up along a central plane?

metaphase II

With 23 pairs of chromosomes humans have over 8 ______ potential different kinds of gametes that can be produced.

million

Random fertilization further increase genetic diversity. Fusing a unique sperm with a unique egg from the same two individuals, the potential number of genetically unique zygotes created is 70 ______.

trillion

True or false: The life cycles of all sexually reproducing organisms alternate between cells with diploid chromosome numbers and cells with haploid chromosome numbers.

true

In ______, sexual reproduction is the predominant mode of reproduction, and allows for genetic recombination and versatility.

vertebrates

The fusion of gametes during fertilization produces a single, diploid cell called a

zygote

The eggs (gametes) produced by an adult human female each contain 23 chromosomes. The number of chromosomes contained in the female's diploid somatic cells would be

46

Humans have 23 pairs of homologues chromosomes, with each gamete receiving one homologue this results in a potential for more than ______ different types of gametes.

8 million

How does a gamete differ from a zygote?

Gametes contain only half of the complement of chromosomes

If only one set of chromosomes is present in the cell, the cell is called BLANK a (1n) cell.

HAPLOID

In a process called BLANK BLANK, chromosomes break in the same place on non-sister chromatids and sections of chromosomes are swapped between the homologous chromosomes

crossing over

What process occurs in prophase I and ties the two chromosomes of a homologous pair together?

crossing over

In what stage of meiosis does crossing over occur?

prophase I

In which phase of meiosis I do the two versions of each chromosome pair up and exchange segments?

prophase I

Meiosis I is traditionally divided into four stages. These stages are

prophase I, metaphase I, anaphase I, and telophase I.

Independent assortment is a process where the ______.

random orientation of homologues results in gametes with different combinations of parental chromosomes

The main outcome of the four stages of meiosis II is to

separate the sister chromatids.

What term describes the non-gametic cells of a sexually-reproducing organism?

somatic

In animals, the diploid cells of the body are called _____ cells, while the diploid, gamete-forming cells are referred to as _____ cells.

somatic; germ-line

What is the process called when homologous chromosomes pair all along their lengths?

synapsis

What process brings homologous chromosomes close enough together to permit crossing over?

synapsis

What are the two unique features that distinguish meiosis from mitosis?

synapsis and reduction division

During meiosis I, synapsis is ______.

the pairing of homologous chromosomes all along their length

What is one role of of crossing over in meiosis I?

tie chromosomes together so that microtubules can only attach to one side of each homologue