BIOL 1010-Reproduction at the Cellular Level Study Guide; Chp. 6

Animal cell nuclei have how many chromosomes and chromatids?

46 chromosomes and 46 chromatids.

Animal cell nuclei have how many chromosomes and chromatids after DNA replication?

46 chromosomes and 92 chromatids.

G₀ Phase (2)

A cell-cycle phase distinct from the G₁ phase of interphase. The cell in G₀ is not preparing to divide.

Cleavage furrow

A constriction formed by the actin ring during animal-cell cytokinesis that leads to cytoplasmic division.

Tumor Surpressor Gene

A gene that codes for regulator proteins that prevent the cell from undergoing uncontrolled division.

Gamete

A haploid reproductive cell or sex cell (sperm or egg).

Oncogene

A mutated version of a proto-oncogene, which allows for uncontrolled progression of the cell cycle, or uncontrolled cell reproduction.

Proto-oncogene

A normal gene that controls cell division by regulating the cell cycle that becomes an oncogene if it is mutated.

Centriole

A paired rod-like structure constructed of microtubules at the center of each animal cell centrosome.

Kinetochore

A protein structure in the centromere of each sister chromatid that attracts and binds spindle microtubules during prometaphase.

Cell plate (2)

A structure formed during plant-cell cytokinesis by Golgi vesicles fusing at the metaphase plate. Will ultimately lead to formation of a cell wall to separate the two daughter cells.

FtsZ

A tubulin-like protein component of the prokaryotic cytoskeleton that is important in prokaryotic cytokinesis (name origin: Filamenting temperature-sensitive mutant Z).

Binary Fission

A type of asexual reproduction in which an organism replicates its DNA and divides in half, producing two identical daughter cells in prokaryotes.

Septum (2)

A wall formed between bacterial daughter cells as a precursor to cell separation. Formed between the nucleoids from the periphery toward the center of the cell.

The G1 checkpoint is used to determine which of the following? A. if adequate reserves and cell size have been reached B. if sister chromatids are attached to spindle microtubules properly C. if the chromosomes have lined up at the metaphase plate D. if DNA replication has finished

A. if adequate reserves and cell size have been reached.

The individual chromosomes become visible with a light microscope during which stage of mitosis? A. prophase B. prometaphase C. metaphase D. anaphase

A. prophase

How many chromosomes do human somatic cells contain? A. 23 B. 46 C. 92 D. 108

B. 46

Chromosomes are duplicated during what portion of the cell cycle? A. G1 phase B. S phase C. prophase D. prometaphase

B. S phase

Human sex cells are also referred to as which of the following? A. body cells B. gametes C. diploid cells D. somatic cells

B. gametes

Which of the following are changes to the nucleotides in a segment of DNA that codes for a protein? A. tumor suppressor genes B. gene mutations C. proto-oncogenes D. negative regulators

B. gene mutations

An organism's traits are determined by the specific combination of inherited ________. A. cells B. genes C. proteins D. chromatids

B. genes

The G2 checkpoint is used to determine which of the following? A. if sister chromatids are attached to spindle microtubules properly B. if DNA replication has finished C. if the chromosomes have lined up at the metaphase plate D. if the chromosomes have finished condensing

B. if DNA replication has finished

The M checkpoint is used to determine which of the following? A. if adequate reserves and cell size have been reached B. if sister chromatids are attached to spindle microtubules properly C. if DNA replication has finished D. if the chromosomes have lined up at the metaphase plate

B. if sister chromatids are attached to spindle microtubules properly.

If the p53 gene is damaged, a cell can behave as though there are which of the following? A. proto-oncogene mutations. B. no mutations C. apoptotic mutations D. more mutations

B. no mutations

Gametes are also called which of the following? A. diploid cells B. sperm and egg cells C. body cells D. somatic cells

B. sperm and egg cells.

________ are changes to the nucleotides in a segment of DNA that codes for a protein. A. Proto-oncogenes B. Tumor suppressor genes C. Gene mutations D. Negative regulators

C. Gene mutations

he alteration of the DNA sequence of gene will most often result in which of the following? A. less functional or non-functional lipids B. a normal protein C. a less functional or non-functional protein D. normal lipids

C. a less functional or non-functional protein

What is necessary for a cell to pass the G2 checkpoint? A. cell has reached a sufficient size B. an adequate stockpile of nucleotides C. accurate and complete DNA replication D. proper attachment of mitotic spindle fibers to kinetochores

C. accurate and complete DNA replication.

Separation of the sister chromatids is a characteristic of which stage of mitosis? A. prometaphase B. metaphase C. anaphase D. telophase

C. anaphase

Separation of the sister chromatids is a characteristic of which stage of mitosis? A. metaphase B. prometaphase C. anaphase D. telophase

C. anaphase.

Uncontrolled cell division can be referred to as which of the following? A. diabetes B. atherosclerosis C. cancer D. mitosis

C. cancer

An organism's traits are determined by the specific combination of inherited ________. A. cells B. chromatids C. genes D.glands

C. genes

Which eukaryotic cell-cycle event is missing in binary fission? A. cell growth B. DNA duplication C. mitosis D. cytokinesis

C. mitosis.

A gene that codes for a positive cell cycle regulator is called a(n) ________. A. kinase inhibitor B. tumor suppressor gene C. proto-oncogene D. oncogene

C. proto-oncogene

A diploid cell has ________ the number of chromosomes as a haploid cell. A. one-fourth B. one-half C. twice D. four times

C. twice

G₁ phase (6)

Called the first gap and the restriction point. A cell-cycle phase. It's the first phase of interphase centered on cell growth during mitosis. The cell is accumulating the building blocks of chromosomal DNA. Determines whether all conditions are favorable for cell division to proceed and checks for damage to the genomic DNA.

Cytokinesis in plant cells differs from that in animals because plant cells have a ______.

Cell wall.

Are centrioles present in centrosome of eukaryotic species and in what organisms?

Centrioles are not present in the centrosomes of many eukaryotic species. Such as plants and most fungi.

The centrosome consists of a pair of rod-like _______________ at right angles to each other.

Centrioles.

Anaphase (3)

Centromeres split in two. The chromosomes separate (two sister chromatids) and are pulled to opposite poles of the cell by the spindle fibers.

Metaphase (2)

Chromosomes are lined up in the middle of the cell at the metaphase plate in a single file line. Each sister chromatid is attached to a spindle fiber originating from opposite poles.

Telophase (5)

Chromosomes arrive at opposite poles and begin to decondense. The nucleolus reappears and the nuclear membrane reappears. Two new nuclei form on each side and cleavage furrow forms.

Cdk stands for what and is a ___________.

Complex of cyclin and kinase;proto-oncogene.

In humans, the homologous chromosomes are which of the following chromosomes? A. 3-22 B. 1-23 C. 1-14 D. 1-22

D. 1-22

Sister chromatids are... A. duplicated chromosomes B. identical copies C. made during S phase D. All of the above

D. All of the above

Which type of life cycle has both a haploid and diploid multicellular stage? A. a sexual life cycle B. diploid dominant C. haploid dominant D. Alternation of generations

D. Alternation of generations.

Normally, when cellular damage has occurred, a fully functional p53 gene will do which of the following? A. Divide slower creating fewer cells. B. Divide like normal. C. Divide faster creating more cells. D. Pause in the cell cycle until the damage is repaired.

D. Pause in the cell cycle until the damage is repaired.

Chromosomes are duplicated during what portion of the cell cycle? A. prometaphase B. prophase C. G1 phase D. S phase

D. S phase

What is necessary for a cell to pass the G2 checkpoint? A. an adequate stockpile of nucleotides B. proper attachment of mitotic spindle fibers to kinetochores C. cell has reached a sufficient size D. accurate and complete DNA replication

D. accurate and complete DNA replication

Half of all human tumor cells have been discovered to contain a mutation in the which of the following genes? A. p47 B. p34 C. p21 D. p53

D. p53

FtsZ proteins direct the formation of a ________ that will eventually form the new cell walls of the daughter cells. A. contractile ring B. cell plate C. cytoskeleton D. septum

D. septum.

Quiescent

Describes a cell that is performing normal cell functions and has not initiated preparations for cell division

Haploid

Describes a cell, nucleus, or organism containing one set of chromosomes (n).

Diploid

Describes a cell, nucleus, or organism containing two sets of chromosomes (2n).

Traits

Different forms of a characteristic.

GTP (guanosine triphosphate) provides _____ to both FtsZ and tubulin in the assembly and disassembly of complex cell structures.

Energy.

In G1 the the cell makes ____________ necessary for S phase and some ___________.

Enzymes;organelles.

Mutations, mistakes made during the replication of a cell's genetic material, are always caught by checkpoints in the cell cycle, killing the abnormal cell. T or F

F.

Plasmids are small loops of genetic material that are essential for a prokaryotic cell's normal growth. T or F

F.

Plasmids are small loops of genetic material that are essential for prokaryotes cell's growth. T or F

F.

Which protein assists during binary fission?

FtsZ.

What order does the cell cycle occur?

G0 ---> G1 ---> S ---> G2 --->M

Which phase is the longest phase in the cell cycle?

G1

Parts of Interphase in order

G1, S and G2 phase.

Checkpoints in the cell cycle

G1, S, G2 and M.

The p53 protein activates other ____________ whose products __________ the cell cycle (allowing time for DNA repair).

Genes;halts.

Sex cells are __________ with ______ set of chromosomes; somatic cells are _________ with _______ sets of chromosomes.

Haploid;1;diploid;2.

Sex cells can be described as _______, while somatic cells can be described as _______.

Haploid;diploid.

Cytokinesis in animal(3) vs. plant cells(6)

In animal cells: 1. A contractile ring composed of actin filaments forms just inside the plasma membrane at the former metaphase plate. 2. The actin filaments pull the equator of the cell inward, forming a fissure. This fissure, or "crack," is called the cleavage furrow. 3. The furrow deepens as the actin ring contracts, and eventually the membrane and cell are cleaved in two In plant cells: 1. A cleavage furrow is not possible because of the rigid cell walls surrounding the plasma membrane. 2. The membrane cannot pinch inward because of the cell wall. 3. Instead, a cell plate forms between the two nuclei. 4. It is made by the Golgi apparatus, which supplies the new plasma membrane. 5. A new cell wall then grows as cellulose and other materials are lad down. 6. Typically, cytoplasm is divided evenly between daughter cells in both plant and animal cells.

Negative regulators and example

Inhibit cell cycle. Ex: p53

2n represents...

Is a diploid organism.

If a mutation occurs in a somatic cell that leads to a non-functional protein, what will happen to that somatic cell?

It will prevent the cell from completing the cell cycle.

Prokaryotic DNA is shaped like a loop, while eukaryotic DNA strands are ______.

Linear.

Cell cycle checkpoints (2)

Mechanisms that monitor the preparedness of a eukaryotic cell to advance through the various cell cycle stages. Regulated by cyclins and cyclin-dependent kinases (Cdk's).

In the G0 phase, are the cells preparing to divide?

No.

Genes

Nucleotide segments and the functional units of chromosomes.

M phase (3)

Occurs near the end of the metaphase stage of mitosis. Known as the spindle checkpoint. Determines if all the sister chromatids are correctly attached to the spindle microtubules.

PMAT occurs ______ in mitosis but ________ in meiosis.

Once;twice.

When proto-concogenes are mutated what do they become?

Oncogenes.

In G2 the rest of the __________ are made.

Organelles.

Centrioles help to do what?

Organize cell division.

What are the two types of protein regulators in the cell cycle?

Positive and negative regulators.

DNA in prokaryotes vs. eukaryotes?

Prokaryotes: The genome is composed of a single, double-stranded DNA molecule in the form of a loop or circle. Eukaryotes: The genome comprises several double-stranded, linear DNA molecules bound with proteins to form complexes called chromosomes.

What are the parts of mitosis (5)?

Prophase, prometaphase, metaphase, anaphase, telophase.

Chromosomes condense during what phase of mitosis?

Prophase.

________ regulate the cell cycle checkpoints.

Proteins.

What are the three types of tumor suppressor genes?

RB1, p21 and p53.

Centromere

Region of a chromosome where the two sister chromatids attach.

n represents...

Represents a single set of chromosomes.

Cytokinesis (2)

Second part of after the mitotic phase during which cell division is completed by the physical separation of the cytoplasmic into two daughter cells. Two daughter cells are formed completely identical to the original parent cell.

What types of cells are divided in mitosis and how many chromosomes do each of the 2 daughter cells have?

Somatic;46.

The M checkpoint is also known as the _____ checkpoint because of where the sister chromatids are attached.

Spindle

Positive regulators and example

Stimulate the cell cycle Ex: Cdk and Cyclin.

Through examining the function and form of FtsZ and tubulin proteins, biologists can find evolutionary links between prokaryotes and eukaryotes. T or F

T.

When a cell replicates and divides, most of the phases of mitosis involve reproduction of the cell's genetic material. T or F

T.

What happens if p53 is mutated (2)?

The cell cycle continues like normal without fixing any cell issues or DNA damages. This can lead to uncontrollable cell growth and the development of tumors.

If the cell doesn't qualify to pass a checkpoint what two options does it have to proceed (2)?

The cell will either pause and not move on until the issue is repaired or resolved; or it will conduct apoptosis (blow up/self destruct) to prevent a mutation from proceeding further.

Genome

The entire genetic complement (DNA) of an organism.

Metaphase plate

The equatorial plane midway between two poles of a cell where the chromosomes align during metaphase.

Prophase (4)

The first stage of mitosis where chromosomes condense and become visible. The spindle fibers emerge from the centrosomes. Nuclear envelope breaks down. Centrosomes move toward opposite poles.

Homologous chromosomes (3)

The matched pairs of chromosomes in a diploid organism. They are the same length and have specific nucleotide segments called genes in exactly the same location. Diploid organisms have pairs of homologous chromosomes, and the members of each pair come from different parents.

Mitotic spindle

The microtubule apparatus that orchestrates the movement of chromosomes during mitosis.

Cell Cycle

The ordered sequence of events that a cell passes through between one cell division and the next before mitosis.

During binary fission, the beginning of DNA replication is what?

The origin.

Mitosis (2)

The period of the cell cycle at which the duplicated chromosomes are separated into identical nuclei. Includes prophase, prometaphase, metaphase, anaphase, and telophase.

Interphase (3)

The period of the cell cycle leading up to mitosis where the cell is preparing to divide (doing DNA replication, growth and cell functions); includes G1, S, and G2 phases. The interim between two consecutive cell divisions.

Mitotic phase

The period of the cell cycle when duplicated chromosomes are distributed into two nuclei and the cytoplasmic contents are divided; includes mitosis and cytokinesis.

Gene (2)

The physical and functional unit of heredity. A sequence of DNA that codes for a specific peptide or RNA molecule.

Locus

The position of a gene on a chromosome.

S phase

The second, or synthesis phase, of interphase during which DNA replication occurs.

Telophase

The stage of mitosis during which chromosomes arrive at opposite poles, decondense, and are surrounded by new nuclear envelopes

Prometaphase

The stage of mitosis during which mitotic spindle fibers attach to kinetochores.

Origin

The starting point of replication.

G₂ phase (4)

Third phase of interphase where the cell undergoes the final preparations for mitosis. The cell replenishes its energy stores and synthesizes the proteins necessary for chromosome manipulation. Bars the entry to the mitotic phase if certain conditions are not met. Ensures that all of the chromosomes have been replicated and that the replicated DNA is not damaged.

One chromosome is composed of _________ sister chromatids.

Two.

Are cell cycle checkpoints are an important part in preventing the growth of cancer tumors in the human body?

Yes.

Are cell cycle checkpoints important in preventing the growth of cancer tumor in the human body?

Yes.

What mutated genes is found in more than half all human cancer tumor cells?

p53

Mutated _____ genes are found in more than half of all human cancer tumor cells.

p53.