Bio Ch 9

Question 0

Interphase

Answer 0

majority of the cell cycle

Question 1

Cell cycle

Answer 1

orderly set of stages that take place between the time a eukaryotic cell divides and the time the resulting daughter cells also divide

Question 2

Chromatid

Answer 2

double helix of DNA

Question 3

Sister chromatids

Answer 3

2 identical chromatids

Question 4

Mitosis

Answer 4

nuclear division

Question 5

Cytokinesis

Answer 5

division of the cytoplasm

Question 6

Mitotic spindle

Answer 6

during mitosis, daughter chromosomes are distributed by this to 2 daughter nuclei

Question 7

Signal

Answer 7

agent that influences the activities of a cell

Question 8

Growth factors

Answer 8

signaling proteins received at the plasma membrane

Question 9

Cyclins

Answer 9

family of internal signaling proteins; increase and decrease as the cell cycle continues

Question 10

p53

Answer 10

signaling protein in mammalian cells that stops the cycle at the G1 checkpoint when DNA is damaged (# = molecular weight in kilodaltons)

Question 11

Apoptosis

Answer 11

programmed cell death

Question 12

RB

Answer 12

protein responsible for interpreting growth signals and also nutrient availability signals; retinoblastoma, a cancer of the retina that occurs when this gene undergoes a mutation

Question 13

Caspases

Answer 13

enzymes that bring about apoptosis

Question 14

Somatic cells

Answer 14

body cells

Question 15

Histones

Answer 15

proteins that are especially involved in organizing chromosomes

Question 16

Chromatin

Answer 16

when a eukaryotic cell is not undergoing division, the DNA and associated proteins are located within this, which has the appearance of a tangled mass of thin threads

Question 17

Diploid (2N) number

Answer 17

full number of chromosomes that is found in all cells of the individual; 2 chromosomes of each kind

Question 18

Haploid (n) number

Answer 18

half the diploid number; contains only 1 chromosome of each kind; only sperm and eggs have this number of chromosomes in the life cycle of animals

Question 19

Centromere

Answer 19

sister chromatids are constricted and attached to each other at this region

Question 20

Kinetochores

Answer 20

protein complexes that develop on either side of the centromere during cell division

Question 21

Centrosome

Answer 21

main microtubule organizing center of the cell; divides before mitosis begins

Question 22

Centrioles

Answer 22

barrel-shaped organelles; pair in each centrosome in an animal cell; not found in plant cells

Question 23

Prophase

Answer 23

nuclear division is about to occur; chromatin has condensed and the chromosomes are visible; nucleolus disappears and the nuclear envelope fragments; spindle begins to assemble as 2 centrosomes migrate away from one another

Question 24

Asters

Answer 24

array of microtubules radiates toward the plasma membrane from the centrosome; serve to brace the centrioles during later stages of cell division

Question 25

Prometaphase

Answer 25

preparations for sister chromatid separation are evident; kinetochores appear on each side of the centromere (attach sister chromatids to the kinetochore spindle fibers)

Question 26

Metaphase

Answer 26

centromeres of chromosomes are in alignment on a single plane at the center of the cell

Question 27

Metaphase plate

Answer 27

an imaginary plane that is perpendicular and passes through the circle in the center of the cell; indicates the future axis of cell division

Question 28

Anaphase

Answer 28

2 sister chromatids of each duplicated chromosome separate at the centromere, giving rise to 2 daughter chromosomes; shortest phase of mitosis

Question 29

Telophase

Answer 29

the spindle disappears as new nuclear envelopes form around the daughter chromosomes

Question 30

Cleavage furrow

Answer 30

indentation of the membrane between 2 daughter nuclei, forms as anaphase draws to a close

Question 31

Cell plate

Answer 31

newly formed plasma membrane that expands outward until it reaches the old plasma membrane and fuses with it; in plant cells

Question 32

Therapeutic cloning

Answer 32

used to produce human tissues; can begin with adult stem cells or embryonic stem cells

Question 33

Reproductive cloning

Answer 33

production of a new individual

Question 34

Cancer

Answer 34

cellular growth disorder that occurs when cells divide uncontrollably

Question 35

Benign

Answer 35

not cancerous

Question 36

Malignant

Answer 36

cancerous & possesses the ability to spread

Question 37

Tumor

Answer 37

abnormal cancer cells pile on top of one another and grow in multiple layers; most aggressive cell becomes the dominant cell of this

Question 38

Metastasis

Answer 38

spread of cancer from the place of origin throughout the body; caused by the ability of cancer cells to migrate and invade tissues

Question 39

Angiogenesis

Answer 39

additional mutations occur in tumor cells, allowing them to direct the growth of new blood vessels into the tumor

Question 40

Proto-oncogenes

Answer 40

code for proteins that promote the cell cycle and prevent apoptosis; likened to the gas pedal of a car because they cause the cell cycle to speed up

Question 41

Tumor suppressor genes

Answer 41

code for proteins that inhibit the cell cycle and promote apoptosis; often linked to the brakes of a car because they cause the cell cycle to go more slowly or even stop

Question 42

Oncogenes

Answer 42

Cancer-causing genes

Question 43

Telomeres

Answer 43

ends of chromosomes

Question 44

Asexual reproduction

Answer 44

offspring are genetically identical to the parent

Question 45

Nucleoid

Answer 45

electron-dense, irregularly shaped region of bacterial chromosomes; not enclosed by a membrane

Question 46

Binary fission

Answer 46

asexual reproductive process of prokaryotes; division (fission) produces 2 (binary) daughter cells that are identical to the original parent cell