lab 5

Question 1

what are the two events in eukaryotic cell reproduction

Answer 1

1. the division of the nucleus

2. cytokinesis: division of the cytoplasm

Question 2

the division of the nucleus may be accomplished by:

Answer 2

mitosis or meiosis

Question 3

mitosis or meiosis:

Answer 3

sets of chromosomes are pulled apart and move to opposite ends of the cell by spindle fibres. this is usually immediately followed by cytokinesis (after telophase)

Question 4

mitosis results in:

Answer 4

two new daughter cells

Question 5

meiosis

Answer 5

undergo a second division to produce four new cells

Question 6

the four phases of the life cycle of a somatic cell

Answer 6

G1, S, G2 and M

Question 7

interphase:

Answer 7

G1, S and G2

Question 8

the five stages of M (mitosis phase)

Answer 8

prophase, prometaphase (not observable in lab), metaphase, anaphase and telophase. continuous- one phase leads to the next without interruption

Question 9

what is the chemical used to prepare a squash slide of a garlic root tip? why?

Answer 9

hydrochloric acid-alcohol. dissolves the cementing material that holds plant cells together. downside: softens the cells other components (ex chromosomes and cell wall) and the dissolving of the mitotic spindle fibres.

Question 10

what is the other chemical?

Answer 10

carnoy’s fluid. reduces further damage to the cells during the remaining steps of the staining procedure. rehardens the cell walls and chromosomes which were previously softened.

Question 11

what are the steps of mitosis

Answer 11

interphase, prophase, prometaphase, metaphase, anaphase, telophase and cytokinesis

Question 12

interphase

Answer 12

chromosomes have already replicated during interphase

Question 13

prophase

Answer 13

sister chromatids condense and the mitotic spindle starts to form. the nuclear envelope begins to dissociate into vesicles.

Question 14

prometaphase

Answer 14

the nuclear envelope has completely dissociated into vesicles and the mitotic spindle is fully formed. sister chromatids attach to the spindle via kinetochore microtubules.

Question 15

metaphase

Answer 15

sister chromatids align along the metaphase plate.

Question 16

anaphase

Answer 16

sister chromatids separate and individual chromosomes move toward the poles as kinetochore microtubules shorten. polar microtubules lengthen and push the poles apart.

Question 17

telophase and cytokinesis

Answer 17

chromosomes decondense and the nuclear envelope re-forms. cytokinesis separates the mother cell into two daughter cells, which begins with a clevage furrow in animal cells.