Cell Division

Question 1

What are the different types of asexual reproduction?

Answer 1

1) binary fission
2) budding
3) spore production
4) vegetative reproduction (no seed - cut off piece of plant to grow another)

Question 2

What are the advantages and disadvantages of asexual reproduction?

Answer 2

+ fast, easy, one parent, many offspring mature quickly

– lacks diversity, enviro changes kill entire pop

Question 3

What are the advantages and disadvantages of sexual reproduction?

Answer 3

+ biodiversity, can cope with change in enviro

– slow, few offspring, two parents needed

Question 4

What do cells do? How/why/what happens?

Answer 4

• grow : by proteins + organelles accumulated in cytoplasm
• divide : surface area of cell membrane becomes inadequate
• die : need to be replaced
• reproduce : passes on genetic material

Question 5

What are chromosomes?

Answer 5

compressed strings of DNA, tightly wound chromatin

Question 6

What is chromatin?

Answer 6

DNA that is unwound, found when cell is not dividing (DNA + Histones [protein] )

Question 7

What are sister chromatids?

Answer 7

chromosome duplicates to make 2 identical copies (DNA replication)

Question 8

What is a centromere?

Answer 8

where chromatids join together

Question 9

What is a telomere?

Answer 9

region of repetitive nucleotide sequences at each end of a chromatid, protects end of chromosome

Question 10

What are genes?

Answer 10

DNA sequences located on chromosomes and code for specific traits

Question 11

What is a genotype? What is a phenotype?

Answer 11

genotype - exact code of DNA

phenotype - how DNA is expressed (looks/functions)

Question 12

What are the two types of cell division?

Answer 12

asexual - mitosis, in somatic cells

sexual - meiosis, in gametes

Question 13

What are the three parts of interphase?

Answer 13

G1 - growth phase
Synthesis - DNA replication (doubling)
G2 - growth / prep for div

Question 14

What is interphase and what happens?

Answer 14

• where the cell spends 90% of its time
• preps cell for div; cell div and makes organelles
• DNA is in form of chromatin
• DNA replication occurs

Question 15

What is mitosis?

Answer 15

• process by which the cell divides
• 10% of the cycle
• cell undergoes cell div

Question 16

What are the stages of Mitosis? IPMAT

Answer 16

1) prophase - chromatin starts to condense into chromosomes
2) metaphase - chromosomes line up
3) anaphase - pulling apart
4) telophase - nucleus starts to appear

Question 17

What is prophase?

Answer 17

• chromatin condenses
• nuclear membrane starts to disintegrate
• astral rays (microtubles) form around centrioles that move to opposite pole of the cell

Question 18

What is metaphase?

Answer 18

• chromosomes line up at equatorial plate
• centromere attaches to spindle fibres and later, splits, separating sister chromatids
• nuclear membrane disappears

Question 19

What is anaphase?

Answer 19

• spindle fibers contract
• chromosomes are pulled to opposite poles
• centromeres divide

Question 20

What is telophase?

Answer 20

• chromatids reach opposite poles
• spindle and astral rays disappear
• chromosomes unwind back into chromatin
• nuclear membrane reforms
• cytokinesis takes place, cell divides in two

Question 21

What’s the difference between plant and animal cells?

Answer 21

1) Plants have no centrioles, but have microtubules with many of the same proteins
2) Plants don’t undergo cytokinesis, instead a cell wall forms at the equator