MITOSIS

Question 1

what is the importance of mitosis

Answer 1

new body cells are needed for growth and to replace that have died or been damaged.

Cells constantly need replacing as they can become wam out, damaged or diseased.

Question 2

what is the average lifespan of a cell

Answer 2

Cells have different life spans depending on their function - intestinal lining with 1.3 days (short life span) to nerve cells in the brain for your whole life.

Question 3

what does mitosis ensure

Answer 3

that each cell receives the same DNA (from parent cell)

Question 4

what is the cell cycle

Answer 4

are the events that take place from one cell division to the next.

Question 5

state the 4 phases of the cell cycle

Answer 5

growth phase 1
synthesis phase
growth phase 2
mitotic phase

Question 6

what is involved in growth phase 1

Answer 6

cell carries out normal tasks and produces new proteins

Question 7

what is involved in the synthesis phase

Answer 7

DNA replication

Question 8

what is involved in growth phase 2

Answer 8

preperation for cell division

Question 9

what is involved in the mitotic phase

Answer 9

cell divides into 2 daughter cells

Question 10

what is interphase

Answer 10

the time between nuclear divisions (G1, S phase and G2, not mitotic phase)

Question 11

prophase

Answer 11

DNA coils to form chromosomes from chromatin.
appear as chromatids

2 pairs of centrioles move to opposite poles and begin to form the microtubules in the spindle fibres

nuclear membrane divides

Question 12

state the 4 phases of mitosis

Answer 12

prophase
metaphase
anaphase
telophase and cytokinesis

Question 13

metaphase

Answer 13

chromosomes line up at the equator

spindle fibres connect to the centromere of the chromosome (chromatid pair)

Question 14

anaphase

Answer 14

separation of chromatids to form individual chromosomes

Spindle fibres contract separating the sister chromatids. Chromosomes are now on opposite poles of the cell.

Question 15

telophase

Answer 15

spindle fibres dissolve

chromosomes uncoil

nuclear membrane reforms

Question 16

cytokinesis

Answer 16

(apart of telophase)

division of cytoplasm
cell splits into 2 identical daughter cells.

Question 17

cell differentiation

Answer 17

a process where stem cells (unspecialised cells) become specialised and can perform a particular function- via mitosis.

Question 18

what are stem cells

Answer 18

unspecialised cells with potential to develop into any cell or provide a source to repair tissues. These cells undergo differentiation.

Question 19

state the 3 types of stem cells

Answer 19

totipotent- exist as an embryo (

pluripotent- capable of giving rise (allow development) to most of the bodies tissues.

multipotent- ability to give rise to a cell with a specific function (blood cell stem cell