MiFUCKINGtosis

Question 1

What is a karyotype

Answer 1

• an ordered, visual representation of the chromosomes in a cell

Question 2

How to make a karyotype

Answer 2

• get cells from blood sample
• treat them with mitogen (which starts process of cell division)
• then treat with colchicine, which stops the process of mitosis
• look at chromosomes in the middle of the process
• stain then with particular stains that highlight diff parts of chromosomes

Question 3

How do you arrange chromosomes

Answer 3

Biggest to smallest

Question 4

Where are genes located

Answer 4

On DNA in chromosomes

Question 5

Locus?

Answer 5

Specific place in chromosome where a specific gene is

Question 6

Allele

Answer 6

Alternate versions of the same gene

Question 7

Two different alleles

Answer 7

Heterozygous

Question 8

Two of the same alleles

Answer 8

Homozygous

Question 9

How many homologous pairs

Answer 9

1-22 are called autosomes
X+Y are sex chromosomes

Question 10

Multicellular organisms depend on cell division for:

Answer 10

• development from a fertilised cell
• growth to adult (10^14 cells)
• repair

Question 11

Interphase phases:

Answer 11

G1 PHASE
- metabolic + growth,
- all organelles + cytoplasmic components including centriole replicate

S PHASE
- metabolic activity, growth
-DNA replicates (synthesis, doubles)

G2
- metabolic activity, growth and preparation for cell division
- enzymes needed to aid the process of cell division are produced

Question 12

Mitotic Phase

Answer 12

• mitosis (produces two daughter cells
• cytokinesis

Question 13

How does DNA change in looks and name after its been duplicated
????? Not sure of correct…

Answer 13

Chromosome is still a chromosome after replication, it just has two sister chromatids too
Doubles DNA - one molecule of DNA goes into one chromatid and one goes into the other
Each sister chromatid contains one whole double stranded DNA molecule

Question 14

5 stages of mitosis which are ______

Answer 14

Continuous stages:
- prophase
- prometaphase
- matephase
- anaphase
- telophase

Question 15

G2 of Interphase

Answer 15

Centrosomes (white centriole pairs just chilling)
Chromosomes (duplicated, uncondenced)
Nuclear membrane intact

Question 16

Prophase

Answer 16

• early mitotic spindle forms between two alesters
• chromosomes condense and become visable
• two sister chromatids of one chromosome held together at centomere

Question 17

Prometaphse

Answer 17

• nuclear envelope (cytoskeleton) disintegrates leaving fragments
• centrosomes has moved to opposite ends of the cell
• Mitotic spindle consists of non-kineticore microtubules and kineticore microtubules
• keneticore microtubules connect via the kineticore to the centromere that holds the two sister chromatids together

Question 18

KENETICORE:

Answer 18

Connects keneticore microtubule to centromere

Question 19

NON KENETICORE

Answer 19

Don’t connect to anything except other non-keneticore microtubules

Question 20

The ______ microtubules, ______ the pairs of ______ ______ via _______

Answer 20

The keneticore microtubules connect the pairs of sister chromotids via keneticals

Question 21

METAPHASE:

Answer 21

• All the pairs of linked chromotids line up along the metaphase plate
• centromeres line up EXACTLY in the middle of the plate
• centromeres remain at poles

Question 22

ANAPHASE:

Answer 22

• begins with the degration of protiens that hold sister chromatids together
• keneticore microtubules shorten and rip apart pairs of sister chromatids
• genetically identical sister chromatids speperate
• each pole of the cell is getting one copy of a chromosome form the original parental cell
• non-keneticore microtubules get longer, pushing two poles apart

Question 23

TELAPHASE

Answer 23

• Begins to ‘reassemble’
• spindle aparatus dissasembles as microtubules are broken down into tubular monomers that can be used to form cytoskeleton of daughter cells
• chromosomes cluster at opposite poles and begin decondencing as the nuclear envelope reforms around them
• cleavage for or forming between two daughter cells

Question 24

What does the contractile ring do and what phase does it occur in

Answer 24

• telophase
• forms a cleavage forrow
• made from a constricting belt of actin filaments surrounding the inside of the cells circumference

Question 25

What happens in cytokinesis

Answer 25

• cells fully split

Question 26

How much time does a cell spend in interphase vs dividing

Answer 26

Most eukaryotic cells spend a lot of time in interphase and a short period of time dividing

Question 27

How does cytokinesis complete cell division in animal cells vs plant cells

Answer 27

Animal: extends cleavbeage barrow to completely seperate the newly formed daughter cells

Plant: can’t be contracted by actin fibres, vessicles form and expand the membrane portion called the cell plate - cytokenesis finishes it

Question 28

What is the purpose of check points?

Answer 28

To ensure the cell cycle is occurring accurately and if it is not the cell cycle will stop at that check point and correct it, or possibly inhabit the cell from dividing

Question 29

3 check points:

Answer 29

G1/S
G2/M
Spindle check point

Question 30

G1/S check point

Answer 30

• primary point where cell cycle continues of stops
• external signals or growth factors can influence the cell and affect progress at or before this critical check point

Question 31

G2/M check point

Answer 31

• allows cells that have successfully completed all 3 phases of interphase to begin mitosis

Question 32

Spindle check point:

Answer 32

• ensures all chromosomes have attached to the spindle in preperation for anaphase

Question 33

3 important factors in cell regulation and what they ensure

Answer 33

• growth factors
• size of cell
• nutritional state of cell
• ensure only certain cells divide at appropriate times

Question 34

How long does interphase take

Answer 34

10 -20 hour process

Question 35

What cells turn over fast

Answer 35

• skin have high turnover rate
• adult neurons and muscle cells rarely divide

Question 36

How do organisms store generic info

Answer 36

Acellular RNA - viruses - double/single stranded DNA or RNA

Prokaryotic - bacteria - circular, single copy, naked double stranded DNA

Eukaryotic - protists, fungi, plants, animals - linear, less than or one single copy, histone - bound DNA; sexual cycle