11.2 Mitotic cell division

Question 1

What is a homologous Chromosome?

Answer 1

matching chromosomes from each parent

Question 2

What is the normal mode of asexual reproduction in unicellular eukaryotic cells?

Answer 2

mitotic cell division

Question 3

What is ploidy?

Answer 3

how many copies of each autosome an organism has

Question 4

In eukaryotic cells DNA is organized with _______ and other proteins into _________, which can be looped and packaged to form the structures we know as _________.

Answer 4

histones, chromatin, chromosomes.

Question 5

What is one of the earliest events in mitosis?

Answer 5

the condensing of chromosomes

Question 6

when do chromosomes condense and become visible?

Answer 6

Mitosis

Question 7

what happens to a chromosomes shape once they condense?

Answer 7

they adopt characteristic shapes and sizes that allow each chromosome to be identifies by its appearance in the microscope

Question 8

What is a karyotype?

Answer 8

the number and visual appearance of the chromosomes in the cell nuclei of an organism or species.

Question 9

most cells in the human body with the exception of gametes, contain

Answer 9

46 chromosomes
23 pairs
22 pairs of homologous chromosomes
1 pair of sex chromosomes

Question 10

which chromosomes are sex chromosomes?

Answer 10

X and Y
famles- 2 X chromosomes
males- 1 X and 1 Y chromosome

Question 11

The number of of complete sets of chromosomes in a cell is know as its

Answer 11

ploidy

Question 12

A cell with one complete set of chromosomes is known as

Answer 12

haploid

Question 13

a cell with two complete sets of chromosomes is known as

Answer 13

diploid

Question 14

Which DNA sequence is more alike? sister chromatids or a pair of homologous chromosomes?

Answer 14

sister chromatids

Question 15

Before cell division, chromosomes must _______

Answer 15

replicate

Question 16

Homologous unreplicated chromosomes occur in what phase?

Answer 16

G1/ G0

Question 17

Homologous replicated chromosomes occur in what phase?

Answer 17

G2, early M

Question 18

What is the centromere?

Answer 18

a region of DNA for microtubules to attach and pull apart.

Question 19

sister chromatids remain connected at the centromere after _________

Answer 19

S Phase

Question 20

At the beginning of mitosis the nucleus of a human cell contains

Answer 20

46 chromosomes which is a pair of sister chromatids linked together

Question 21

during mitosis, the sister chromatids ________ to __________

Answer 21

separate from each other to opposite ends of the cell.

Question 22

What are the 5 stages of mitosis?

Answer 22

1. prophase
2. pro metaphase
3. metaphase
4. anaphase
5. telophase
   (PPMAT)

Question 23

what is the first stage of mitosis and how is it characterized?

Answer 23

prophase

characterized by the appearance of visible chromosomes

Question 24

Where and in what phase is the mitotic spindle assembled?

Answer 24

outside the nucleus in the cytosol, the cell begins to assemble the mitotic spindle. prophase

Question 25

what is the mitotic spindle made up of and what is their function?

Answer 25

mostly of microtubules that pull the chromosomes into separate daughter cells

Question 26

what are a few important functions of the centrosome?

Answer 26

- a microtubule organizer center for animal cells - the structure from which the spindles radiate - plant cells don't have one but to have mitotic spindle

Question 27

as preparation for mitosis during S Phase, the centrosome

Answer 27

duplicates and migrates around the nucleus halting at opposite ends of the cell to start prophase.

Question 28

What occurs when the centrosomes migrate to opposite poles?

Answer 28

tubular dimers assemble around them forming microtubules that radiate from each each centrosome forming the mitotic spindle.

Question 29

What occurs during prophase?

Answer 29

chromosomes condense and become visible

Question 30

What occurs during pro metaphase?

Answer 30

the nuclear envelope breaks down and the microtubules of the mitotic spindle attach to chromosomes

Question 31

What occurs during metaphase?

Answer 31

chromosomes align in the centre of the cell as a result of

Question 32

What occurs during anaphase?

Answer 32

Sister chromatids separate and travel to opposite poles

Question 33

What occurs during telophase?

Answer 33

the nuclear envelope re-forms and chromosomes decondense

Question 34

when do sister chromatids separate in anaphase?

Answer 34

when the centromere splits

Question 35

Where are kinetochores located, in what phase? and what are they?

Answer 35

one located on each side of the centromere during pro metaphase. They are protein complexes

Question 36

what is the function of a kinetochore?

Answer 36

associated with each sister chromatid, and for the attachment site for a single spindle microtubule

Question 37

What occurs once each chromosome is attached to he mitotic spindles from both poles?

Answer 37

The microtubules and mitotic spindle lengthen or shorten to move chromosomes into position in the middle of the cell.

Question 38

What is the mitotic spindle made up of?

Answer 38

microtubules (component of the cytoskeleton)

Question 39

during prophase what proteins do chromosomes condense into?

Answer 39

histone proteins

Question 40

during pro metaphase why does the nuclear envelope disassemble?

Answer 40

so the spindle can interact with condensed chromosomes

Question 41

What must happen before sister chromatids can separate from each other in anaphase?

Answer 41

the centromere holding the sisters to gather must split.

Question 42

During telophase how are the sister chromatids pulled to opposite sides of the cell?

Answer 42

the spindle microtubules and kinetochores gradually shorten pulling the chromosomes to opposite poles

Question 43

What event marks the beginning of telophase?

Answer 43

once the complete set of chromosomes arrives at a pole, which is the area where the cytosol will form of the new Daughter cell

Question 44

What major events happen during telophase?

Answer 44

microtubules and the mitotic spindle break down and disappear, while the nuclear envelope reformed around each new set of chromosomes, creating 2 new nuclei and chromosomes decondense

Question 45

The parent cell divides into two daughter cells by_________

Answer 45

cytokinesis

Question 46

As mitosis comes to an end ________ begins and the parent cell divides into __________

Answer 46

cytokinesis, two daughter cells.

Question 47

what happens when cytokinesis starts in animal cells?

Answer 47

the contractile ring forms agains the inner face of the membrane. the ring contracts pinching the cytoplasm of the cell and dividing it in two.

Question 48

what is the difference between binary fission and cytokinesis?

Answer 48

binary fission driven by FtsZ protein and homolog tubular. | Cytokinesis driven by motor proteins that slide bundles of actin microfilaments in opposite directions.