Module 4

Question 1

2 reasons why cells divide

Answer 1

Grew too large (increase SA:V ratio)
Replace a dead cell

Question 2

Why does DNA stop working well as the cell grows?

Answer 2

DNA doesn’t increase in size

Question 3

Does the surface area and volume of a cell equal each other or no?

Answer 3

They do not equal the same amount

Question 4

What is cell division? How is it beneficial?

Answer 4

A cell divides into 2 daughter cells; identical to the original. It decreases the size, reducing the strain and cell volume

Question 5

As the cell enlarges, what happens to the SA to Volume ratio?

Answer 5

Decreases
Ex: 6:1 … 2:1

Question 6

What are the types of reproduction?

Answer 6

Asexual and sexual

Question 7

What are the benefits and drawbacks of asexual reproduction?

Answer 7

Doesn’t need two organisms ~ easier with a lower population
Genes do not change, no adaption

Question 8

What are the benefits and drawbacks of sexual reproduction?

Answer 8

Different genes ~ can adapt
Needs 2 parents; difficult with low population

Question 9

What are the differences in DNA between eukaryotes and prokaryotes?

Answer 9

Eukaryotes: DNA in the nucleus, more DNA, chromosomes
Prokaryotes: DNA in cytoplasm

Question 10

What are the 4 phases of cell division AND what happens during the phase

Answer 10

G1: Growth
S: DNA Synthesis (2x DNA as beginning)
G2: Growth+Prep for Mitosis (shortest, organelles and molecules are produced)
M: Mitosis (2 daughter cells; mitosis and cytosis stages)

Question 11

What is/happens during the second stage of mitosis?

Answer 11

Metaphase: centromeres of chromosomes line up through cell center, spindle fibers connect to centromeres

Question 12

What is/happens during the third stage of mitosis?

Answer 12

Anaphase: chromatids separate into 2 separate groups

Question 13

What is/happens during the first stage of mitosis?

Answer 13

Prophase: genetic materials shrink, spindle forms in centrosome, centrioles move to opposite ends of cell

Question 14

What is/happens during the fourth stage of mitosis?

Answer 14

Telophase: chromosomes spread into chromatin, nuclear envelope reforms, nucleus forms in daughter cells

Question 15

What happens during cytokinesis in animal cells?

Answer 15

Cell membrane pinches inward, forming cleavage furrow

Question 16

What happens during cytokinesis in plant cells?

Answer 16

Cell plate forms between nuclei, forms cell wall later

Question 17

What is asexual cell division called?

Answer 17

Binary fission

Question 18

What happens during binary fission?

Answer 18

DNA is replicated,cytoplasmic membrane elongates to separate DNA, cross wall forms + membrane leaves, cross wall fully separates new daughter cells

Question 19

What is the difference between centrosomes, centrioles, and centromeres?

Answer 19

Centrosomes: end of cell where spindle fibers come from
Centrioles: pieces in center of centrosome
Centromeres: center of chromosomes

Question 20

What is the difference between chromosomes and chromatids?

Answer 20

Chromosomes are made of two chromatids

Question 21

What is cyclin?

Answer 21

A regulatory protein that regulates the cell cycle

Question 22

What are the types of regulatory proteins, what do they do?

Answer 22

Internal: makes cell cycle wait for the previous step to finish correctly
External: signals to speed or slow the cycle

Question 23

What are growth factors?

Answer 23

They help the growth/division rates, but slows other cells’ cycles (filling chair example)

Question 24

What is apoptosis?

Answer 24

Programmed cell death; important for development

Question 25

What happens during apoptosis?

Answer 25

cell + chromatin shrink membrane breaks off neighbor cells clean excess

Question 26

What does cancer do?

Answer 26

Takes nutrients from healthy tissues

Question 27

Causes of cancer

Answer 27

Genetics, infections, smoking/tobacco, radiation; all with no control of cell cycle

Question 28

Treatments for cancer

Answer 28

Localized: surgery General: radiation (chemotherapy)

Question 29

What does chemotherapy do?

Answer 29

Kills the cancer cells, but also harms healthy cells in the process

Question 30

What is the alternate stage of mitosis?

Answer 30

Go: rest stage, can't get out of, no division

Question 31

What is an internal regulator? (Throughout the mitosis cycle)

Answer 31

Checkpoints (ex. DNA copied correctly, spindle fibers attached to chromatids)

Question 32

What are the types of tumors?

Answer 32

Benign and malignant

Question 33

What are the characteristics of benign tumors?

Answer 33

Not cancerous, slower spreading, noninvasive

Question 34

What are the characteristics of malignant tumors?

Answer 34

Cancerous, spread quickly

Question 35

Metastasis?

Answer 35

Spread of tumor cells throughout whole body