1.1- division and differentiation in human cells

Question 1

what are somatic cells?

Answer 1

non-sex cells that make up all the cells in the human body other than gametes

Question 2

4 things made up by somatic cells

Answer 2

smooth muscle cells

red blood cells

b lymphocytes

epithelial cells

Question 3

how many chromosomes do somatic cells contain?

Answer 3

46 (23 homologous pairs) (diploid)

Question 4

how do somatic cells divide and what into?

Answer 4

mitosis

divide into daughter cells which may then divide to form more cells

Question 5

what does the division of somatic daughter cells result in?

Answer 5

increase in size of the body and its organs

Question 6

what are germline cells?

Answer 6

cells that eventually leads to the formation of sex cells (gametes)

Question 7

how many chromosomes do germline cells contain?

Answer 7

46 (23 homologous pairs) (diploid)

Question 8

what happens when a germline cells nucleus divides by mitosis?

Answer 8

it maintains the diploid chromosome number

Question 9

what types of nuclear division do germline cells undergo?

Answer 9

mitosis

meiosis

Question 10

what is meiosis?

Answer 10

process that produces haploid gametes intended to fuse with another gamete to produce a zygote

Question 11

process of meiosis

Answer 11

original germline cells contains 23 homologous pairs of chromosomes

division 1

homologous pairs of chromosomes separated and each cell contains 23 homologous chromosomes

division 2

chromosomes separated and 4 haploid cells are made each showing genetic variation

Question 12

what cells do mitosis and meiosis take place in?

Answer 12

germline cells

Question 13

summary of mitosis and meiosis

Answer 13

mitosis- germline stem cells divide and produce more germline cells

meiosis- produces haploid gametes

Question 14

what is cellular differentiation?

Answer 14

process by which a cell expresses certain genes to produce proteins characteristic for that type of cell

Question 15

what does cellular differentiation allow a cell to do?

Answer 15

carry out a specialised function

Question 16

what 3 things are stem cells?

Answer 16

undifferentiated

found in all multicellular organisms

self-renewing and can differentiate

Question 17

3 things tissue stem cells are involved in

Answer 17

growth, repair, renewal of cell types making up an individual

Question 18

what do tissue stem cells differentiate into?

Answer 18

differentiate into all of the types of cell found in a particular tissue type

Question 19

example of a tissue stem cell and 4 things it gives rise to

Answer 19

blood stem cells located in bone marrow

red blood cells
platelets
phagocytes
lymphocytes

Question 20

what are tissue stem cells described as being?

Answer 20

multipotent

Question 21

what do embryonic stem cells differentiate into?

Answer 21

cells in the very early embryo differentiate into all cell types that make up an individual

Question 22

how do embryonic stem cells differentiate?

Answer 22

all the genes in embryonic stem cells can be switched on

Question 23

what are embryonic stem cells described as being?

Answer 23

pluripotent

Question 24

what can stem cells in the embryo do under the right conditions in a lab?

Answer 24

self renew

Question 25

what does **therapeutic** mean?

Answer 25

use in medical treatments

Question 26

2 **therapeutic uses** of stem cells

Answer 26

corneal repair regeneration of damaged skin

Question 27

**what happens during corneal repair?**

Answer 27

stem cells grown from patients own stem cells located at the edge of the cornea grafting of the stem cell tissue from the healthy eye to the surface of the damaged eye eyesight can be restored

Question 28

**what happens during the regeneration of damaged skin?**

Answer 28

skin graft using stem cells requires a small sample of skin to obtain stem cells site needs much less healing time and suffers minimum scarring sample normally taken from an area close to and similar structure to the site of injury enzymes used to isolate and loosen the stem cells which are then cultured once suspension of new stem cells has developed, they are sprayed over the damaged area to bring about regeneration of missing skin

Question 29

what happens in **traditional skin grafts**?

Answer 29

relatively large section of skin is removed can lead to infection and longer healing time

Question 30

2 **research uses** of stem cells

Answer 30

model cells to study how diseases develop drug testing

Question 31

what 3 things does stem cell research **provide information** on?

Answer 31

cell growth cell differentiation gene regulation work

Question 32

what **ethical issues** are there surrounding stem cell research?

Answer 32

involves destruction of an embryo- a potential human life

Question 33

what do **cancer cells** do?

Answer 33

divide excessively to produce an abnormal mass of cells don't respond to normal regulatory signals instructing them to stop dividing when necessary

Question 34

what do cancer cells **result in**?

Answer 34

abnormal mass of cells called a tumour

Question 35

how are **secondary tumours** made?

Answer 35

cells within the tumour may fail to attach to each other, spreading through the body where they may form secondary tumours