Chapter 9,16.3 Study Guide

Question 1

Why is cell division necessary? What are the 3 situations in which cell division occurs?

Answer 1

It helps life continue. Functions in reproduction, growth, and repair

Question 2

Reproduction in cell division

Answer 2

division of unicellular, reproduces an organism

Question 3

growth in cell division

Answer 3

enables multicellular organism to develop from egg

Question 4

repair in cell division

Answer 4

repair and renew cells that die from wear and tear

Question 5

genome

Answer 5

cell’s DNA, genetic infoC

Question 6

Chromosomes

Answer 6

hold genome, long linear DNA

Question 7

How much DNA does one chromosome contain?

Answer 7

46 DNA (23 mom, 23 dad) with multiple genes

Question 8

Chromatin

Answer 8

made up of DNA, RNA, and proteins and forms chromosomes

Question 9

somatic cells

Answer 9

all cells in an organism except for reproductive

Question 10

gametes

Answer 10

eggs or sperm

Question 11

homologous chromosomes

Answer 11

a pair of chromosomes that are similar in size, shape, and genetic information, but are not identical (mother and fathers)

Question 12

sister chromatids

Answer 12

identical copy of one of the DNA molecules (still 1 chromosome) replicated chromosomes, identical

Question 13

What is the longest phase in the cell cycle? Why?

Answer 13

Interphase, because it contains G1, S, and G2

Question 14

What happens in G1

Answer 14

growth phase, organelles, nutrients, general preparation of cell

Question 15

S phase

Answer 15

DNA replication

Question 16

G2 Phase

Answer 16

Growth, double checks that the replicated DNA is ready for mitosis

Question 17

M phase

Answer 17

division of the nucleus of cell (not cytoplasm)

Question 18

What does G1 checkpoint check for?

Answer 18

unduplicated chromosomes, determines if the cell is ready to divide

Question 19

Prophase

Answer 19

chromatin coil and compact, forming visible chromosomes or x shaped sister chromatids, centrosomes go to opposite sides of the cell

Question 20

Metaphase

Answer 20

all the replicated chromosomes line up in the middle of the cell, nuclear membrane is gone

Question 21

Anaphase

Answer 21

the sister chromatids of each chromosome separate at the centromere and are pulled apart by the spindle fibers creating double the amount of chromosomes, moving towards opposite poles of the cell, distributing identical copies of genetic material to the future daughter cells

Question 22

Telophase

Answer 22

the chromosomes reach the poles of the cell, a nuclear membrane reforms around each set of chromosomes, the spindle fibers disassemble, and the chromosomes begin to decondense

Question 23

cytokinesis

Answer 23

the cytoplasm of a single cell is physically divided into two separate daughter cells

Question 24

difference in eukaryotic and prokaryotic cell division

Answer 24

eukaryotic involves mitosis or meiosis, mitosis produces 2 identical daughter cells, prokaryotic involves binary fission to produce the 2 identical daughter cells

Question 25

During mitosis, eukaryotes ____ _____ breaks to allow spindle to attach to chromosomes. However with prokaryotes, DNA is _____ ( )

Answer 25

nuclear envelope, directly accessible (no envelope)

Question 26

In eukaryotic cytokinesis occurs in___
In prokaryotic cytokinesis occurs in ___

Answer 26

cleavage furrow, cell plate

Question 27

What is a prokaryotes mode of reproduction, eukaryotes?

Answer 27

binary fission, sexually through meiosis and gamete fusion, and asexually through mitosis

Question 28

how many chromosomes does a prokaryotic cell have? shape?

Answer 28

one chromosome, single circular DNA molecule

Question 29

How many chromosomes does a eukaryotic cell have? shape?

Answer 29

46 chromosomes 23 pairs, long linear straight strands of DNA

Question 30

G1 checkpoint checks for?

Answer 30

that cell is ready for DNA replication, before S phase, enough nutrients? DNA undamaged?

Question 31

G2 checkpoint checks for?

Answer 31

before mitosis, makes sure it is ready to divide, was it replicated properly? healthy?

Question 32

M checkpoint checks for

Answer 32

during metaphase, ensures chromosome allignment before chromosomes are separated into daughter chromosomes

Question 33

Tumor supressor “___” does what

Answer 33

p53; normally regulate cell cycle and limit growth or division, promote apoptosis, can halt the cycle at g1/sphase and allow dna time to repair

Question 34

what has to happen in order for p53 to cause cancer?

Answer 34

both copies need to be missing, when p53 is damaged or missing, it can’t kill cancer cells, so they replicate

Question 35

Proto-oncogenes “___” do what?

Answer 35

ras; normal functioning gene, become oncogenes when mutated, oncogenes can cause cancer when introduced into the cell and can become hyperactive

Question 36

how can ras cause cancer

Answer 36

one mutated ras gene, mutated gene continues to spread

Question 37

Describe estrogen, progesterone, and HER2 receptors involvement in development of breast cancer

Answer 37

Breast cancer tumors show high amounts of HER2, which also show an increase in the number of estrogen receptor molecules that can trigger cell division.

Question 38

What does chemotherapy do for breast cancer?

Answer 38

Herceptin binds to the HER2 receptor and prevents it from pairing w/ other HER2, this leads to a decreased activation of downstream signaling, which can lead to apoptosis

Question 39

how do chemotherapy drugs impact mitosis

Answer 39

inhibition of microtubule function (can’t separate chromosomes during anaphase), inhibition of DNA synthesis (cause breaks in DNA or prevents replication S phase),

Question 40

main difference in tumor suppressors and oncogenes

Answer 40

tumor suppressors repair DNA or can initiate apoptosis while oncogenes are a mutated version of proto-oncogenes that are overactive, tumor suppressors are recessive meaning both copies have to be mutated for it to cause harm, oncogenes are dominant meaning one mutated gene would cause harm