Unit 1 KA1 - differentiation

Question 1

what is cellular differentiation?

Answer 1

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

Question 2

give an example of cellular differentiation.

Answer 2

a basic animal cell becoming specialised into a goblet cell in the trachea.
this goblet cell then expresses the genes for making proteins found in mucus.

Question 3

how does a cell become specialised?

Answer 3

by the switching on and off of genes.

Question 4

give examples of differentiated cells.

Answer 4

muscle cells, goblet cells, nerve cells and red blood cells.

Question 5

what is a stem cell and what can it do?

Answer 5

they are unspecialised cells in animals that can continue to divide to make copies of themselves and differentiate into specialised cells.

Question 6

wat are the two types of stem cells?

Answer 6

embryonic and tissue.

Question 7

embryonic stem cells are described as …………

Answer 7

pluripotent.

Question 8

where are tissue stem cells found?

Answer 8

the brain, skin, testicles, breast, bone marrow, intestines, muscles and cornea.

Question 9

tissue stem cells are described as ……………., which means they can only produce the ……… of cell types found in a …………… …………… type.

Answer 9

multipotent, range, particular tissue.

Question 10

what is a somatic cell?

Answer 10

any cell in the body other than cells involved in reproduction.

Question 11

how do somatic cells form more somatic cells?

Answer 11

dividing by mitosis.

Question 12

each somatic cell contains ….. chromosomes and is ……..

Answer 12

46, diploid.

Question 13

the cell that produces gametes is a …………

Answer 13

germline stem cell.

Question 14

where are germline stem cells found?

Answer 14

ovaries and testes.

Question 15

germline stem cells can divide by……….. to produce ……. germline (…………) cells.

Answer 15

mitosis, more, diploid.

Question 16

germline stem cells can divide by ……. to produce gametes (…………) cells.

Answer 16

meiosis, haploid.

Question 17

name the first and second divisions of meiosis.

Answer 17

homologous chromosomes separated, chromatids separate.

Question 18

cancer cells ………. excessively to produce a mass of ……….. cells called a …………

Answer 18

divide, abnormal, tumor.

Question 19

tumour cells do not ………. to …………. signals and may ……… to ……….. to each other.
………….. tumours form if ………… cells ……. to attach to each other so they ………… through the body.

Answer 19

respond, regulatory, fail, attach, secondary, cancer, fail, spread.

Question 20

give examples of the therapeutic use of stem cells.

Answer 20

corneal transplants, regeneration of damaged skin.

Question 21

in research, stem cells can be used as ……… to study how ………. develop and to ……… drugs.

Answer 21

model cells, diseases, test.

Question 22

stem cells research provides info on how cell processes work such as;

Answer 22

cell growth, differentiation and gene regulation.

Question 23

give an ethical issue surrounding the use of embryonic stem cells.

Answer 23

results in destruction of the embryo .

Question 24

what are differentiated cells?

Answer 24

Cells that have become specialised to carry out their various specific functions.

Question 25

How many chromosomes are found in somatic cells?

Answer 25

46

Question 26

Name the process by which germline cells produce more germline cells.

Answer 26

mitosis.

Question 27

Name the process by which germline cells produce gametes.

Answer 27

meiosis.

Question 28

List three diseases that could potentially be treated using transplanted cells originated from embryonic stem cells.

Answer 28

Any three from:
diabetes;
Duchenne's;
muscular dystrophy;
heart disease;
Parkinson's disease;
traumatic spinal cord injury;
vision and hearing loss.

Question 29

give an example of a therapeutic use of stem cells.

Answer 29

burn victim patients, where the epidermis and the delicate tissue of the dermis are damaged, are often treated using skin grafts of their own skin.
To prepare a graft, a section of healthy skin is removed from an undamaged part of the patient’s body. This is then grown in special nutrient solutions, which encourage the epidermal stem cells to divide, and a graft for the burn site is produced from this culture.