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