eukaryotic cell division - mitosis (lecture 14)

Question 1

how do eukaryotes store information

Answer 1

protists, fungi, plants, animals are examples that store their genetic info
- chromosomes (linear genome)
- type (double-stranded DNA)

Question 2

describe a karyotype

Answer 2

• an ordered, visual representation of the chromosomes in a cell
• where chromosomes are ordered by size and sex chromosomes are present
• and are often taken during metaphase when all duplicated chromosomes align at the metaphase plate by there centromeres

Question 3

outline the cell cycle

Answer 3

the process of a dividing cell including the lead up and the afterward of mitosis
interphase:
- G1 phase
- S phase
- G2 phase
mitotic phase
- mitosis
- cytokinesis

Question 4

describe a duplicated chromosome

Answer 4

• made up of 2 genetically identical sister chromatids
• connected by the centromere
• each chromatid is a double stranded DNA molecule
• these seperate during mitosis

Question 5

outline G2 of interphase

Answer 5

• nuclear envelope is intact and the nucleolus itself is intact
• the two centrosomes form here
• duplicated chromosomes are ye to condense

Question 6

outline the 5 stages of mitosis in order

Answer 6

1 prophase
2 prometaphase
3 metaphase
4 anaphase
5 telophase & cytokinesis

Question 7

outline prophase, when does it occur within mitosis and what occurs

Answer 7

first step of mitosis
- duplicated chromosomes become visible as they condense
- mitotic spindles begin to form as the microtubules protrude from the centrosomes
- this begins to push the two centrosomes to opposite poles N/S of the cell

Question 8

outline prometaphase when does it occur within mitosis and what occurs

Answer 8

second step of mitosis
- chromosomes are now fully condensed
- lengthening of microtubules reduce the room within the cell and make the nuclear envelope degenerate
- proteins called kinetochores form at the centromere of each chromatid (2 per chromosome)
- microtubules connect to the kinetochore proteins of the chromatids called kinetochore microtubules
- the nonkinetochore microtubules that do not attach continue to lengthen the cell when interacting with opposing nkmt

Question 9

outline metaphase when does it occur within mitosis and what occurs

Answer 9

third step of mitosis
- centrosomes at opposing poles
- all sister chromatids are attached to a kinetochore microtubule
- the duplicated chromosomes begin to align at the metaphase plate by their centromere independently from their pairs
- distance between the metaphase plate and the spindles two poles are equal

Question 10

outline anaphase when does it occur within mitosis and what occurs

Answer 10

fourth step of mitosis
- sister chromatids disjoin at their centromeres creating independent daughter chromosome
- kinetochore microtubules pull independent daughter chromosomes towards opposite poles
- cell continues to enlongate by lengthening of nonkinetochore microtubules
- anaphase ends upon each pole contains identical, complete collections of chromosomes

Question 11

outline telophase when does it occur within mitosis and what occurs

Answer 11

part of the fifth stage of mitosis (put back together stage)
- chromosomes begin to lengthen back out
- spindle microtubules begin to breakdown
- 2 daughter nuclei form ready for cell to split to two
- the cell division required processes are now complete

Question 12

outline cytokinesis when does it occur within mitosis and what occurs

Answer 12

last part of the fifth stage of mitosis
- the cytoplasm splits dividing the cell into two daughter cells
animal cells:
- cleavage furrow pinches the cell in two for final cell splitting/division
plant cells:
- cell plate is formed between the daughter cells