Science (cell division and mitosis) Flashcards
1
Q
- How many reasons are there for cell division?
2. What is the 1rst reason?
A
- 3
2. they need to or else they wont survive
2
Q
Why is it bad for cells not to divide and become big?
A
if cells too big, no longer get enough nutrients and oxygen
3
Q
- What is the second reason for cell division?
- Why do cells need to be replaced?
- What is the name of cells that don’t reproduce?
A
- cellular regeneration is needed to repair damaged tissue
- they have a life span
- amitotic
4
Q
What is the third reason for cell division?
A
growth
5
Q
What are the 2 principal parts that make up a cell’s life?
A
- cell division
- interphase
6
Q
- What happens during G1 phase?
- What happens during the synthesis phase?
- What happens during G2 phase?
A
- offspring cells grow to maturesize, following cell division
- cells mature in size, DNA is replicated
- second growthphase in which the cell prepares for cell division
7
Q
- What happens during DNA replication?
2. What does each strand of the double helix of DNA do?
A
- DNA molecules produce two new complementary strands following the rules of “base pairing”
- guide to build other half
8
Q
- Where does replication of the DNA begin?
- What’s the name of the enzyme that breaks hydrogen bonds between the DNA strands and unwinds the double helix?
- What do proteins do?
A
- origin of replication
- DNA helicase
- bind the DNA strands to keep them from joining together again
9
Q
- What happens during elongation?
- What is the enzyme that attaches new nucleotides to the growing DNA strands and also proofreads to make sure there are no errors?
A
- 2 new strands of DNA are formed
2. DNA polymerase
10
Q
What happens once the new DNA strands are completed?
A
DNA rewinds back to its helix
11
Q
How pairs of chromosomes do we have?
A
23 pairs (2n=46) (each pair is made up of a chromosome inherited from mother and father)
12
Q
- During mitosis, replicated forms _______ that separate.
- What happens to the nucleus?
- Then what happens to the cytoplasm?
A
- chromosomes
- divides into 2
- divides to yield two identical daughter cells
13
Q
What are the four phases of mitosis?
A
P rophase
M etaphase
A anaphase
T elophase
14
Q
- What happens to chromatin during prophase?
- What is visible now?
- What structure moves to opposite ends of the cell?
- What extends between two opposite poles of the cell?
A
- condenses into chromosomes
- chromosomes
- centrioles
- spindle fibers
15
Q
- What happens to copied chromosomes during metaphase?
2. What do chromosomes attach to?
A
- line up alng the center of the cell (metaphase plate)
2. spindle fiber
