BIO CH12

APC

"anaphase promoting complex" -at M checkpt must have all kinetochores attached to move to anaphase -enzyme separase breaks cohesin of sister tids

MPF

"mitosis promoting factor" -protein of CDK + cyclin that allows for mitosis --> must have enough to pass G2 phase

MITOSIS

"nuclear div" 1.prophase ->condensing 2.metaphase -> aligning 3.anaphase -> separating 4.telophase -> reforming of 2 nuc envelopes

KINETOCHORE MICROTUBULES

connect to kinetochore of chromatids to seperate sisters

NONKINETOCHORE MICROTUBULES

connect to other microtubs to elongate cell during anaphase

CHECKPOINTS

control pts where stop and go-ahead signals of regulating cell cycle (G1, G2, M)

CENTRIOLES during cell div

dont know how duplicated...BUT must have pre-existing to get a new one

REGULATION DESTRUCTION MECHANISM

machinery breakdown of tubules and cyclins --> actin and ubiquitin degrade

SPINDLE

made of microtubules -->tubulin! -control chrom mvmt in cell cycle -cytoskeleton

CENTROMERE

most close attachement of sister tids

ER + GOGLI during cell div

network of tubes where breakage allows split into daughter cells...can reform

TRANSFORMATION

normal cell converted to cancerous --> malignant!

SISTER CHROMATID

pair of duplicated chroms attached by centromere

CELL DIVIDION/CYCLIN DEPENDENT KINASE (CDK)

protein important for cell cycle regulation

INTERPHASE

1.G1 -> growth (can it go thru cell div?) 2.S -> DNA replication 3.G2 -> more growth (proper nucleotide copies) **also have Go phase --> resting

PHYSICAL FACTORS OF CELL REG

1.density depend inhibition --> crowded so stop 2.anchorage dependence --> to divide must be attached to anchor

CHEMICAL FACTORS OF CELL REG

1.lacking/having nutrients 2.growth factor --> P15/P16(block CDK); P21/P27(block cyclin); PDGF(injury)

CYCLIN

A regulatory protein whose concentration fluctuates cyclically during cell divison

KINETOCHORE

A structure of proteins attached to the centromere that links each sister chromatid

CENTRIOLES

Cell organelle that aids in cell division in animal cells only

CHROMATIN

DNA and protein that makes up chromosomes

If there are 20 chromatids in a cell, how many centromeres are there? a) 10 b) 20 c) 40 d) 30

a) 10 *NOTE:* 1 per each pair

Movement of the chromosomes during anaphase would be most affected by a drug that a) prevents shortening of microtubules. b) reduces cyclin concentrations. c) prevents attachment of the microtubules to the kinetochore. d) prevents elongation of microtubules

a) prevents shortening of microtubules.

MALIGNANT TUMOR

able to spread! --> fatal and termed as cancerous

GENOME

all DNA in cell

Which of the following most accurately describes a cyclin? a) It decreases in concentration when MPF activity increases. b) It activates a CDK molecule when it is in sufficient concentration. c) It is activated to phosphorylate by complexing with a Cdk. d) It is present in similar concentrations throughout the cell cycle.

b) It activates a CDK molecule when it is in sufficient concentration.

A mutation results in a cell that no longer produces a normal protein kinase for the M phase checkpoint. Which of the following would likely be the immediate result of this mutation? a) The cell would prematurely enter anaphase. b) The cell would undergo normal mitosis, but fail to enter the next G1 phase. c) The cell would never enter metaphase. d) The cell would never leave metaphase. e) The cell would never enter prophase.

b) The cell would undergo normal mitosis, but fail to enter the next G1 phase. *NOTE:* bc in G1 phase has checkpt if should go to new cell div or go thru apoptosis --> cell death

The centromere is a region in which a) chromosomes are grouped during telophase. b) chromatids remain attached to one another until anaphase. c) the nucleus is located prior to mitosis. d) new spindle microtubules form at either end.

b) chromatids remain attached to one another until anaphase.

At which phase are centrioles beginning to move apart in animal cells? a) prometaphase b) prophase c) telophase d) anaphase

b) prophase

Which of the following does not occur during mitosis? a) separation of sister chromatids b) replication of the DNA c) cell cycles lacking an S phase. d) spindle formation e) condensation of the chromosomes

b) replication of the DNA

Suppose a biologist can separate one of a dozen pieces of chromatin from a eukaryotic (animal) nucleus. It might consist of which of the following? a) two chromosomes, each with six chromatids b) two long strands of DNA plus proteins c) two chromatids attached together at a centromere d) a single circular piece of DNA

b) two long strands of DNA plus proteins

SOMATIC CELLS

body cells --> 46 chroms

For anaphase to begin, which of the following must occur? a) Cohesin must attach the sister chromatids to each other. b) Spindle microtubules must begin to depolymerize. c) Cohesin must be cleaved enzymatically d) Kinetochores must attach to the metaphase plate.

c) Cohesin must be cleaved enzymatically

One difference between cancer cells and normal cells is that cancer cells a) cannot function properly because they are affected by density-dependent inhibition. b) are unable to synthesize DNA. c) continue to divide even when they are tightly packed together. d) are arrested at the S phase of the cell cycle.

c) continue to divide even when they are tightly packed together.

Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor? a) inability to form spindles b) inability of chromosomes to meet at the metaphase plate c) lack of appropriate cell death d) changes in the order of cell cycle stages

c) lack of appropriate cell death

BENIGN TUMOR

cannot move from orig. location --> will not spread to affect other organs

BINARY FISSION

cell divions/asexual reproduction of prok

A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in a) anaphase. b) metaphase. c) G2 d) G1

d) G1

Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells? a) kinetochores b) cyclin-dependent kinases c) centrioles and centromeres d) Golgi-derived vesicles

d) Golgi-derived vesicles

The cyclin component of MPF is destroyed toward the end of which phase? a) G1 b) G0 c) G2 d) M

d) M

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely a) a plant cell in metaphase. b) a bacterial cell dividing. c) an animal cell in the process of cytokinesis. d) a plant cell in the process of cytokinesis. e) an animal cell in the S phase of the cell cycle.

d) a plant cell in the process of cytokinesis.

Where do the microtubules of the spindle originate during mitosis in both plant and animal cells? a) kinetochore b) centriole c) centromere d) centrosome

d) centrosome

KARYOKINESIS

div of nucleus

CYTOKINESIS

divison of cytoplasm

Which of the following triggers the cell's passage past the G2 checkpoint into mitosis? a) protein kinase b) CDK c) PDGF d) cyclin e) MPF

e) MPF

Which of the following best describes how chromosomes move toward the poles of the spindle during mitosis? a) Nonkinetochore spindle fibers serve to push chromosomes in the direction of the poles. b) Motor proteins of the kinetochores move the chromosomes along the spindle microtubules. c) The chromosomes are "reeled in" by the contraction of spindle microtubules, motor proteins of the kinetochores move the chromosomes along the spindle microtubules, and nonkinetochore spindle fibers serve to push chromosomes in the direction of the poles. d) The chromosomes are "reeled in" by the contraction of spindle microtubules. e) The chromosomes are "reeled in" by the contraction of spindle microtubules, and motor proteins of the kinetochores move the chromosomes along the spindle microtubules.

e) The chromosomes are "reeled in" by the contraction of spindle microtubules, and motor proteins of the kinetochores move the chromosomes along the spindle microtubules.

The MPF protein complex turns itself off by a) exiting the cell. b) binding to chromatin. c) activating an enzyme that stimulates cyclin. d) activating the anaphase-promoting complex. e) activating a process that destroys cyclin components.

e) activating a process that destroys cyclin components.

Why do chromosomes coil during mitosis? a) to allow the chromosomes to fit within the nuclear envelope b) to increase their potential energy c) to allow the sister chromatids to remain attached d) to provide for the structure of the centromere e) to allow the chromosomes to move without becoming entangled and breaking

e) to allow the chromosomes to move without becoming entangled and breaking

DNA POLYMERASE

enzyme involved in DNA replication that adds nucleotides in Sphase (precise!)

CHLORO + MITO during cell div

have own DNA to go thru binary fission to create some for each daughter cell

CANCER CELL ______ REGULATION

ignore proper cell

ABUNDANT ORGANELLES during cell div

ribos and peroxisomes --> so many throughout cell that wherever seperate both daughters will have some

GAMETES

sex cells --> 23 chroms (meiosis!)

SISTER TID COHESION

sister chromatids attached along entire length by this protein

METASTASIS

spread of cancer cells from original site

CENTROSOME

structure that organizes mitotic spindle

DAUGHTER CELLS

the two new cells that result from mitosis and cytokinesis

CHROMOSOMES

thread like structures made of DNA molecules that contain the genes