Biology 111 - Chapter 10 Smartbook

One complete set of chromosomes necessary to define an organism

haploid number

During telophase, the nuclear envelope re-forms to produce two separate nuclei cells chromosomes

nuclei

In most fungi and some protists, the nuclear membrane does not break down before mitosis, therefore, mitosis takes place within the

nucleus

During cell division, chromatin becomes increasingly more condensed with one of the highest states of condensation seen in X-shaped metaphase chromosomes. In these structures, DNA is organized ____________.

on a protein scaffold

In bacterial cells, the replication of DNA begins at a specific site called

origin of replication

The metaphase plate is perpendicular to the axis of the spindle and located halfway between the poles perpendicular to the axis of the spindle and located near one of the poles parallel to the axis of the spindle and located halfway between the poles parallel to the axis of the spindle and located near one of the poles

perpendicular to the axis of the spindle and located halfway between the poles

Cytokinesis in plant cells involves the formation of a cell _________ which starts at a right angle to the spindle apparatus in the interior of the cell and extends out to the plasma ___________.

plate, membrane

After DNA replication each condensed chromosome is made of two identical halves called

sister chromatids

In eukaryotic chromatin, topologically associated domains (TADs) are composed of loops of DNA that are anchored by two proteins

the CTCF and the cohesin complex of proteins.

Place the events in the order they occur (starting at the top) during the segregation of bacterial chromosomes during binary division.

1. Replication begins at the origin of replication 2. Origins move to the opposite ends of the cell 3. The entire replicated chromosomes move to the opposite ends of the cell 4. Two new nucleoids are assembled 5. Chromosomes are untangled

The chromosome number in the body cells of most eukaryotic species falls within which range?

10 and 50

Typically, a dividing mammalian cell completes its cell cycle in about how many hours? 8 hours 2 hours 72 hours 24 hours 100 hours

24 hours

Chromatin is a complex with 40% DNA and ______.

60% Protein

In a typical, mature, dividing mammalian cell, what proportion of the cell cycles is taken by mitosis? A very small fraction (about 5%) A very large fraction (almost 95%) About 50%

A very small fraction (about 5%)

When does cytokinesis take place? After mitosis At the end of anaphase Immediately before mitosis During metaphase

After mitosis

At the beginning of which phase do the centromeres of sister chromatids split apart allowing sister chromatids to separate from each other? Metaphase Anaphase Prophase Telophase

Anaphase

The shortest stage of mitosis

Anaphase

Sister chromatids are pulled towards opposite poles as their kinetochore microtubules, which are attached to the poles, are shortened.

Anaphase A

During anaphase, chromosomes move towards the opposite poles of the cell using two types of movements. What are those movements usually called? Late anaphase Anaphase I Early anaphase Anaphase II Anaphase A Anaphase B

Anaphase A Anaphase B

During anaphase, two forms of movement take place simultaneously and as a result sister chromatids are pulled towards opposite poles of the cell. The two forms of movement are commonly referred to as

Anaphase A and Anaphase B

Microtubules slide past each other pulling the poles anchored to them, and the chromosomes attached to the poles, away from the center of the cell. metaphase A anaphase B metaphase B anaphase A

Anaphase B

In which type of cell is an aster apparent during mitosis? Animal and plant Animal Bacteria Plant

Animal

Which cell type relies on centrioles to form the spindle apparatus during mitosis? Plant Animal Bacterial All eukaryotic cells

Animal

What are the two basic mechanisms that have been proposed as the forces that move chromosomes toward the equator of the cell? Assembly and disassembly of actin networks that connect chromosomes to microtubules and the plasma membrane Assembly and disassembly of spindle microtubules Motor proteins located along the spindle microtubules Motor proteins located at the kinetochore and poles of the cell

Assembly and disassembly of spindle microtubules Motor proteins located at the kinetochore and poles of the cell

The nucleosome core includes two each of four histones named

H2A, H2B, H3, and H4

(1) Refers to similar structures that have the same evolutionary origin. (2) Refers to a pair of the same kind of chromosome in a diploid cell.

Homologous

One of a pair of chromosomes of the same kind located in a diploid cell

Homologue

Cytokinesis in animal cells involves the formation of a ____________ furrow around the cell

Cleavage

When DNA replicates, the sister chromatids are held together at their centromeres by which of the following complex of proteins? Adhesins Condensin Cohesins DNA polymerases

Cohesins

Which statement accurately compares cell division in bacterial and eukaryotic cells? In bacteria, cell division produces two new cells with the same genetic information as the original cell, while in eukaryotes, the two new cells have slightly different genetic information. In both types of cells, cell division produces two new cells with the same genetic information as the original cell. In both types of cells, cell division produces two new cells with slightly different genetic information compared to the original cell. In eukaryotes, cell division produces two new cells with the same genetic information as the original cell, while in bacteria, the two new cells have slightly different genetic information.

In both types of cells, cell division produces two new cells with the same genetic information as the original cell.

Some animal cells, such as muscle and nerve cells, remain permanently in which of the following phases of the cell cycle? G1 phase G0 phase S phase G2 phase

G0 phase

In a cell's life, cell growth occurs primarily during what phase? G0 M S G1

G1

Fruit flies have the shortest known animal cell cycle because they lack which of the following stages? G1 Prophase S G2

G1, G2

What are the three checkpoints at which the cell cycle can be delayed, or even halted, depending on the cell's internal state and any external signals it may have received? S/G2 G1/G2 G1/S checkpoint G2/M checkpoint Metaphase checkpoint

G1/S checkpoint G2/M checkpoint Metaphase checkpoint

In animal cells, centrioles are replicated during which phase of the cell cycle? G0 G1 G2 S

G2

In actively dividing cells, the G1, S, and G2 phases are collectively known as which of the following? Interphase Anaphase Prophase Metaphase

Interphase

While preparing to divide, the cell grows and copies its chromosomes during which stage? Anaphase Metaphase Interphase Telophase

Interphase

Choose the correct features of the nucleosome core particle. It contains 20-80 bp of DNA. The nucleosome core particle has a diameter of about 30 nm. It contains 147 bp of DNA. The DNA is wrapped in 2 right-handed turns around the nucleosome protein core. The nucleosome core particle has a diameter of about 10 nm. The DNA is wrapped in 1.7 left-handed turns around the nucleosome protein core.

It contains 147 bp of DNA. The DNA is wrapped in 1.7 left-handed turns around the nucleosome protein core. The nucleosome core particle has a diameter of about 10 nm.

Which of the following describes the number of chromosomes in eukaryotic cells? It is the same in almost all species. It varies considerably between different species. It varies very little from species to species.

It varies considerably between different species.

During metaphase, the microtubules attached to the centromere region of the condensed chromosomes are which of the following types of microtubules? Centromere Aster Polar Kinetochore

Kinetochore

During prometaphase, which protein complex on each sister chromatid attaches to the spindle? Centromere Centriole Kinetochore

Kinetochore

Choose all true statements about the activity of MPF. MPF activity varies during the cell cycle. MPF acts as a protein kinase. MPF activity has a low, constant activity throughout the entire cell cycle. MPF acts as a protein phosphatase.

MPF activity varies during the cell cycle. MPF acts as a protein kinase.

MPF is an acronym for

Maturation-promoting factor

The pairs of sister chromatids align themselves in a single row along a plane half-way between the poles during which phase of mitosis? Cytokinesis Metaphase Prometaphase Telophase

Metaphase

An imaginary plane halfway between the poles along which chromosomes align during mitosis.

Metaphase plate

During the formation of the spindle apparatus which of the following must break down? Nuclear membrane Golgi apparatus Plasma membrane Mitochondria

Nuclear membrane or Nuclear envelope

A complex consisting of a DNA duplex wound around a core of eight histone proteins.

Nucleosome

In a homologous pair of chromosomes, what is the origin of each chromosome? One is paternal and one is maternal. They are either both paternal, or both maternal (depends on the particular pair). One is original and one is a copy produced during replication.

One is paternal and one is maternal.

Which of the following activities in a bacterial cell require the FtsZ protein? Septation Cell division Replication of DNA Elongation

Septation Cell division

The group of proteins involved in the compaction and organization of bacterial DNA in the nucleoid

Structural Maintenance of Chromosome (SMC) proteins

The final phase of mitosis

Telophase

What phase of mitosis is characterized by the reformation of the nuclear envelope and the production of two separate nuclei? Cytokinesis Metaphase Telophase Anaphase

Telophase

When is the spindle apparatus broken down? Prophase Telophase Anaphase Metaphase

Telophase

Cleavage furrow

The area of the cell membrane that pinches in and eventually separates the dividing cell

Condensin and cohesin are SMC proteins that unravel DNA from nucleosomes increase the coiling of DNA around nucleosomes remove loops from DNA can induce DNA to form loops

can induce DNA to form loops

When studying yeast division, scientists discovered the presence of two control points, both of which required the gene

cdc2

During cytokinesis in plants, the newly formed cell plate is coated with ________ to form two new cell walls

cellulose

If necessary (e.g., if DNA is damaged), the cell cycle can be arrested at specific points called phases checkpoints cyclins CDKs

checkpoints

A karyotype is a visual representation of an individual's alleles gametes chromosomes genes

chromosomes

The key event in anaphase is the removal of ________ proteins from the centromeres of sister chromatids. histone condensin cohesin SMC

cohesin

Protein kinases that regulate the cell cycle and are only active when complexed with the protein cyclin are called kinase-cyclin complexes cyclin kinases cyclin-dependent kinases cell cycle kinases

cyclin-dependent kinases

After completing mitosis, cells divide into two daughter cells. This phase of the cell cycle is called

cytokinesis

Which statement accurately compares chromatin condensation in dividing and nondividing cells? The chromatin of a cell undergoing division is more condensed than the chromatin of a nondividing cell. Overall, the chromatin is always condensed to the same extent, although certain regions may become more or less condensed during cell division. The chromatin of a cell undergoing division is relatively diffuse compared to the highly condensed chromatin of a nondividing cell.

The chromatin of a cell undergoing division is more condensed than the chromatin of a nondividing cell.

During the segregation of the duplicated bacterial chromosome, which part of the chromosome moves towards opposite ends of the cell first? The origins of replication The terminations of replication The entire nucleoids The replication forks

The origins of replication

The two most significant events in mitosis are

The separation of sister chromatids The partitioning of genetic material during anaphase

The protein that is necessary for septation and cell division in bacteria.

FtsZ

What enzymes control the progression of cells through the cell cycle checkpoints? MPFs MAP kinases Cdks Checkpoint phosphatases

Cdks

What is a sequence of growth, replication, and division that produces new eukaryotic cells called? Cell growth Cell cycle Karyotyping Cell division

Cell cycle

What usually occurs during the G1 phase?

Cells are growing

During cytokinesis in plants, what coats the newly formed cell plate? Chitin Lipids Proteins Cellulose

Cellulose

Which structures, typical of animal cells, are replicated during the G2 phase? Centromeres Sister chromatids Kinetochores Centrioles

Centrioles

The complex of DNA and proteins of which eukaryotic chromosomes are composed

Chromatin

During cell division, the two complete daughter cells are produced after the cell undergoes which of the following? Cytokinesis Anaphase Telophase Metaphase

Cytokinesis

The phase of the cell cycle when the cell divides into two equal halves.

Cytokinesis

Which of the following organelles reabsorbs the components of the nuclear membrane as it breaks down during prophase of mitosis? Endoplasmic reticulum Golgi apparatus Plasma membrane Lysosome

Endoplasmic reticulum

If the sister chromatids are attached to microtubules from the same polar region of the cell, which of the following is/are likely to occur? Failure of the sister chromatids to separate One daughter cell will receive both of the sister chromatids Each cell will receive the correct number of chromosomes Sister chromatids will separate

Failure of the sister chromatids to separate One daughter cell will receive both of the sister chromatids

In which of the following cells does cytokinesis involve the formation of a cell plate? Bacterial cells Plant cells Animal cells

Plant cells

Condensation of chromosomes continues throughout which phase of mitosis? Telophase Metaphase Prophase

Prophase

Which is the first stage of mitosis? Metaphase Anaphase Prophase Telophase Prometaphase

Prophase

Chromosomes are composed of chromatin which is a complex of DNA and which of the following?

Protein

The enzymatic activity of MPF involves the phosphorylation of which types of molecules? Proteins Carbohydrates Lipids Nucleic acids

Proteins

Which of the following is the key event in anaphase? Removal of cohesin proteins from the centromeres of sister chromatids Elongation of the cell's nonkinetochore microtubules Migration of chromosomes in a plane, located in the center of the cell

Removal of cohesin proteins from the centromeres of sister chromatids

During which phase of the cell cycle does replication of each chromosome and its centromere take place? S G2 G1

S

During which phase of the cell cycle are the chromosomes replicated? G1 phase M phase S phase G2 phase

S phase

How do chromosomes move to the equator of the cell during prometaphase? Because the nucleus of the cell is typically positioned in the equator of the cell prior to mitosis, the chromosomes are released at that location when the nuclear envelope breaks down. They are pulled simultaneously toward the two poles of the cell because each kinetochore in a pair of sister chromatids is connected to the opposite pole. They slowly diffuse towards the equator which is devoid of organelles.

They are pulled simultaneously toward the two poles of the cell because each kinetochore in a pair of sister chromatids is connected to the opposite pole.

MPF is composed of two parts

a cyclin component a kinase component (cdc2)

During anaphase B, microtubules slide past each other pulling the poles anchored to them away from the center of the cell. At the same time, chromosomes are also pulled apart because _________. a different set of microtubules attaches the chromosomes to the poles as the poles are pulled apart, the cytoplasm flows towards them, carrying the chromosomes with it the same set of microtubules that pulls the poles also pulls the chromosomes

a different set of microtubules attaches the chromosomes to the poles

The cleavage furrow of animal cells is formed with the help of a constricting belt made of the protein

actin

The radial arrangement of microtubules around the polar centrioles in an animal cell is called a(n)

aster

The total number of chromosomes in a cell

diploid number

The cells of many eukaryotic organisms contain two sets of chromosomes and are said to contain a

diploid number of chromosomes

During cell division in both bacterial cells and eukaryotic cells, genetic information is _________________ and segregated and the contents of the cell are divided between the daughter cells.

duplicated

The inactive domains of chromatin in a nondividing nucleus are referred to as

heterochromatin

Each chromosome in a pair is termed a

homologue

In a diploid eukaryotic cell, a pair of chromosomes, one maternal and the other paternal, are known as being

homologus chromosomes

Cell division in both bacterial and eukaryotic cells produces genetically _________ cells

identical

At the end of telophase, cell division

is not yet complete

A visual representation of the number, size, and shape of chromosomes is called a DNA fingerprint PCR genotype karyotype

karyotype

The morphology of the chromosomes of an organism as viewed with a light microscope.

karyotype

In a eukaryotic cell, each nucleosome core is separated from the next one by a variable length of DNA of 20-80 bp called

linker DNA