Chapter 8

Question 1

What steps occur in a sexual life cycle?

Answer 1

Mitosis, meiosis, and fertilization.

Question 2

What happens in sexual reproduction?

Answer 2

2 parents produce genetically variable gametes by meiosis. Fertilization produces a zygote.

Question 3

Mitosis cell division produces identical eukaryotic cells used for what?

Answer 3

Growth, tissue repair, and asexual reproduction.

Question 4

What is apoptosis?

Answer 4

Programmed cell death

Question 5

What does apoptosis do?

Answer 5

Shapes structures and kills cells that could become cancerous.

Question 6

What happens after the cell receives the signal to die?

Answer 6

Enzymes destroy the cell’s components. Immune system cells dispose of the remains.

Question 7

What is necrosis?

Answer 7

Cell death due to trauma or infection.

Question 8

Prophase

Answer 8

chromosomes are condensing and the spindle fibers start to form

Question 9

Prometaphase

Answer 9

nuclear envelopes begin to break down and spindle fibers attach to kinetochores at the centrosome

Question 10

Metaphase

Answer 10

replicated chromosomes align along cells center

Question 11

Anaphase

Answer 11

chromatid of each replicated chromosomes seperate

Question 12

Telophase

Answer 12

the spindle fibers break down and nuclear envelopes form

Question 13

What does a contractile ring form?

Answer 13

cleavage furrow (the indentation of the cell’s surface that begins the progression of cleavage)

Question 14

What forms as plant cells divide between two daughter cells?

Answer 14

cell plate

Question 15

How does cancer arise?

Answer 15

when cells divide out of control

Question 16

What regulates cell division?

Answer 16

chemical signals

Question 17

What stimulates cell division that may pause or halt at multiple check points during the cell cycle?

Answer 17

external signals called growth factors

Question 18

When does DNA Replication happen?

Answer 18

before cell division (mitosis) during interphase

Question 19

Dividing cells must 1st do what?

Answer 19

duplicate its genome which consists of 1 or more chromosomes

Question 20

Helicase enzymes do what?

Answer 20

unwind and unzip DNA

Question 21

What keeps strands seperate?

Answer 21

binding proteins

Question 22

__ adds DNA nucleotides to RNA primer.

Answer 22

DNA polymerase

Question 23

What seals nicks after the primer is replaced with DNA ?

Answer 23

Legase

Question 24

What do DNA replication errors produce?

Answer 24

mutations

Question 25

How do prokaryotes divide?

Answer 25

binary fission

Question 26

Step 1 of binary fission:

Answer 26

DNA first replicates

Question 27

Step 2 of binary fission:

Answer 27

2 chromosomes attach to the cell membrane

Question 28

Step 3 of binary fission:

Answer 28

cell growth between the attachment points separates the chromosomes into 2 identical daughter cells

Question 29

Replicated chromosomes do what as a eukaryotic cell prepares to do divide?

Answer 29

condense

Question 30

What does a chromosome consist of?

Answer 30

chromatin (DNA+protein)

Question 31

Where are the 2 identical sister chromatids of a chromosome attached?

Answer 31

to the centromere

Question 32

How is chromatin organized?

Answer 32

in nucleosomes

Question 33

How can tumors occur?

Answer 33

from excess cell division or deficient apoptosis

Question 34

Cancer cell break through cell cycles. True or false

Answer 34

true

Question 35

Do benign tumors spread?

Answer 35

no

Question 36

Does a malignant tumor spread?

Answer 36

yes, by invading nearby tissues and metastasizes if it reaches the bloodstream

Question 37

What is cancer?

Answer 37

a family of diseases characterized by malignant cells.

Question 38

How do cancer cells divide?

Answer 38

uncontrollaby

Question 39

What happens when telamere becomes very short?

Answer 39

divison ceases

Question 40

Cancer cells produce an enzyme called?

Answer 40

telamerase (angiogenic factors)

Question 41

Cancer cells continue to divide even after growth factors depleted. True or false

Answer 41

true