Modern Biology Ch 8 Mult Choice

In order to fit within a cell, DNA becomes more compact by

a. breaking apart into separate genes.
b. extending to form very long, thin molecules.
c. wrapping tightly around associated proteins.
d. being enzymatically changed into a protein.

wrapping tightly around associated proteins.
c.

Chromatids are

a. dense patches within the nucleus.
b. bacterial chromosomes.
c. duplicate halves of a chromosome.
d. prokaryotic nuclei.

duplicate halves of a chromosome.
c.

A protein disk that attaches two chromatids to each other in a chromosome is called a

a. chloroplast.
b. centromere.
c. gamete.
d. centriole.

centromere.
b.

Which of the following is not a true difference between the chromosomes of eukaryotes and those of prokaryotes?

a. Eukaryotic chromosomes are linear, while those of prokaryotes are circular.
b. Eukaryotic chromosomes are found free in the nucleus, while those of prokaryotes are attached to the cell membrane.
c. Eukaryotes usually have more than one chromosome, while prokaryotes have only one chromosome.
d. Eukaryotic chromosomes contain DNA, while prokaryotic chromosomes contain a different form of genetic material.

Eukaryotic chromosomes contain DNA, while prokaryotic chromosomes contain a different form of genetic material.
d.

The chromosomes in your body

a. exist in 23 pairs.
b. include two sex chromosomes.
c. include 44 autosomes.
d. all of the above.

All of the above.
d.

A student can study a karyotype to learn about the

a. molecular structure of a chromosome.
b. genes that are present in a particular strand of DNA.
c. medical history of an individual.
d. number of chromosomes present in a body cell.

number of chromosomes present in a body cell.
d.

diploid : body cell :: haploid :

a. sex chromosome
b. chromosome
c. reproductive cell
d. zygote

reproductive cell
c.

The diploid number of chromosomes in a human skin cell is 46. How many chromosomes are in a human egg cell?

a. 46
b. 92
c. 23
d. 12.5

23
c.

How many chromosomes are in the body cells of an organism that has a haploid number of 8?

a. 4
b. 8
c. 12
d. 16

16
d.

Binary fission

a. occurs when two cells collide with each other.
b. produces excess energy.
c. creates new species.
d. is the process by which bacteria reproduce.

is the process by which bacteria reproduce.
d.

The chromosome of a bacterium

a. is wrapped around proteins.
b. has a circular shape.
c. occurs in multiple pairs within the cell.
d. is found within the nucleus.
e. None of the above.

has a circular shape
b.

The stage of the cell cycle that occupies most of the cell’s life is

a. G1.
b. M.
c. G2.
d. interphase.

interphase.
d.

Which of the following shows the correct sequence of the cell cycle?

a. C ==> M ==> G1 ==> S ==> G2
b. S ==> G1 ==> G2 ==> M ==> C
c. G1 ==> S ==> G2 ==> M ==> C
d. none of the above

G1 ==> S ==> G2 ==> M ==> C
c.

growth : G1 ::

a. mitosis : meiosis
b. mitochondria replication : S
c. cytokinesis : M
d. DNA copying : S

DNA copying : S
d.

metaphase : prophase ::

a. anaphase : cytokinesis
b. G2 : S
c. thylakoid : grana
d. carbon fixation process : Calvin cycle

G2 : S
b.

The phase of mitosis that is characterized by the arrangement of all chromosomes along the equator of the cell is called

a. telophase.
b. metaphase.
c. anaphase.
d. prophase.

metaphase
b.

A spindle fiber is a specialized form of

a. microtubule.
b. flagellum.
c. cilium
d. chromosome.

microtubule.
a.

Name the 5 steps of Mitosis in the order that they occur.
Interphase
Prophase
Metaphase
Anaphase
Telophase

The chromosomes which have produced a copy of themselves, become X shaped sister chromatids and the nuclear membrane disappears becoming part of the cytoplasm.
Prophase

The cell membrane collapses over the two new cells and daughter nuclei are born with the same genetic instructions and RNA as the parent cell.
Telophase

The strands of sister chromatids line up in the center of the cell and the centrioles migrate to the opposite poles of the cell.
Metaphase

The chromatid become visible as long strands of chromosomes. Mitosis begins with this stage.
Interphase

The sister chromatid separate to opposite poles.
Anaphase

A typical human cell contains 46 chromosomes. After mitosis and cytokinesis, each of the two new cells formed from the original cell.

a. has 23 chromosomes.
b. grows new chromosomes from existing DNA.
c. has a complete set of 46 chromosomes.
d. None of the above .

has a complete set of 46 chromosomes.
c.

As a result of mitosis, each of the two new cells produced from the original cell during cytokinesis
a. receives a few chromosomes from the original cell.

a. receives a few chromosomes from the original cell.
b. receives an exact copy of all the chromosomes present in the original cell.
c. donates a chromosome to the original cell.
d. receives exactly half the chromosomes from the original cell.

receives an exact copy of all the chromosomes present in the original cell.
b.

In plant cells, cytokinesis occurs when
a. the chromosomes make exact copies of themselves.

b. spindle fibers are formed.
c. a new cell wall forms.
d. osmotic pressure is too low.

a new cell wall forms.
c.

Mitosis is a process by which
a. DNA is replicated.
b. cytokinesis occurs.
c. cells grow in size.
d. a cell’s nucleus divides.
a cell’s nucleus divides.
d.

Which of the following statements is true?

a. Prokaryotes divide by mitosis.
b. Eukaryotes have circular chromosomes.
c. Animal cells form new cell walls when they divide.
d. Cytokinesis differs in plant cells and animal cells.

Cytokinesis differs in plant cells and animal cells.
d.

Separation of homologues occurs during

a. mitosis.
b. meiosis I.
c. meiosis II.
d. fertilization.

meiosis I.
b.

The difference between anaphase of mitosis and anaphase I of meiosis is that

a. the chromosomes line up at the equator in anaphase I.
b. centromeres do not exist in anaphase I.
c. chromatids do not separate at the centromere in anaphase I.
d. crossing-over occurs only in anaphase of mitosis.

chromatids do not separate at the centromere in anaphase I.
c.

When crossing-over takes place, chromosomes

a. mutate in the first division.
b. produce new genes.
c. decrease in number.
d. exchange corresponding segments of DNA.

exchange corresponding segments of DNA.
d.

The exchange of segments of DNA between the members of a pair of chromosomes

a. ensures that variation within a species never occurs.
b. acts as a source of variations within a species.
c. always produces genetic disorders.
d. is called crossing.

acts as a source of variations within a species.
b.