Unit 1

Question 1

Potential uses of stem cells

Answer 1

Crowns disease
Diabetes
Deafness
Blindness
Stroke

Question 2

How have unspecialised cells become specialised

Answer 2

In structure and in biochemical properties

Question 3

Zygote

Answer 3

Fertilised egg

Question 4

Somatic cell

Answer 4

Cell division by mitosis

More somatic cells each with the diploid number of chromosomes

Question 5

Germline cells

Answer 5

Cell division by mitosis
More germline cells with the diploid number of chromosomes
Cell division by meiosis
Sex cells formed with the haploid number of chromosomes

Question 6

Diploid

Answer 6

2 sets of chromosomes

Question 7

Haploid

Answer 7

1 set of chromosomes

Question 8

Somatic cells

Answer 8

Are differentiated cells that form the different types of body tissue that exist
Specialised cells
Any cell in the body other than those involved in reproduction
Diploid
Cardiac muscle

Question 9

Germline cells

Answer 9

Include the gametes and the cells that produce the gametes
Are sperm and ova (gametes) and the stem cells that divide to form gametes
Are found in gonads tested and ovaries

Question 10

Division of germilne cells

Answer 10

Can divide by mitosis to produce more germiline cells which maintains the diploid chromosome number
Gamers mother cells divide by meiosis to produce gametes

Question 11

Mitosis stages

Answer 11

Parent cell at rest
Chromosomes are seen under the microscope and become condensed and nucleus dissolves
Chromosomes make a copy of themselves and line up across the equator
Chromosomes become chromatids as the spindle fibres contract to pull the pairs of chromosomes apart to each side of the centromere where they are now called chromatids
Cytoplasm dissolves
Nuclei reform around the cell
2 genetically identical daughter cells are made to ensure no genetic material is lost

Question 12

Meiosis

Answer 12

Germline cell undergoes 2 divisions
1st division separates the homologous chromosome pairs
2nd division separates the chromatids like mitosis
Meiosis results in the formation of haploid gametes

Question 13

Where does meiosis occur

Answer 13

Reproductive organs

Question 14

Boy

Answer 14

Xy

Question 15

Girl

Answer 15

Xx

Question 16

Stem cells

Answer 16

Embryonic and adult these are unspecialised cells that can continue to divide and can differentiate into specialised cells of various types

Question 17

Somatic cells

Answer 17

These cells divide by mitosis to produce more somatic cells they form different body tissues such as muscle,nerve and bone

Question 18

Germline cells

Answer 18

These cells can divide by mitosis to produce more germline cells or by meiosis to produce gametes

Question 19

Cancer cells

Answer 19

These cells divide excessively by mitosis to produce a mass of abnormal cells

Question 20

What is a gene

Answer 20

Section of DNA that codes and makes a specific protein

Question 21

Stem cell features

Answer 21

Are able to self renew by mitosis

Differentiate to specialised cells

Question 22

What are stem cells

Answer 22

Unspecialised cells that have the ability to reproduce and differentiate into a diverse range of specialised cells

Question 23

What are embryonic stem cells

Answer 23

Are derived from the embryo about 4-5 days old (bastocyst)
Cells have the ability to differentiate into all cell types that make an organism
Pluripotent
Unlimited capacity

Question 24

Stem cell research

Answer 24

How cell processes such as growth, gene regulation work and differentiate
Study of diseases
Drug testing
Therapeutic uses in treatment of diseases such as leukaemia hunters disease and heart disease
Therapeutic uses in medicine including skin graphs for burns and stem cell grafts for cornea repair

Question 25

Where are adult tissue stem cells found

Answer 25

Brain Bone marrow Skin Skeletal muscle

Question 26

Adult tissue stem cells

Answer 26

Multipotent Replenish differentiated cells that need replaced in the tissues which they are found Cells give rise to a much more limited range of cell types and will tend to develop into cell types that are closely related to the tissue in which they are found Limited capacity

Question 27

How do cells become differentiated by selective gene expression

Answer 27

Only a small fraction of genes about 3-5% are switched on in a typical specialised human cell

Question 28

Differentiation

Answer 28

When unspecialised cells which are embryonic stem cells and adult stem cells have the ability to divide to form specialised cells such as red blood cells

Question 29

Germline cells

Answer 29

If a mutation occurs this is passed onto the next generation

Question 30

Somatic cells

Answer 30

Do not pass a mutation to the members of the next generation

Question 31

Metastasis

Answer 31

They lose their molecules on their surface that would normally hold them in a place and can therefore be detached from their neighbours causing the cells to spread

Question 32

Cancer cells characteristics

Answer 32

Are able to continue to reproduce and form a mass of abnormal cells They do not respond to normal regulatory signals that would instruct them to stop dividing

Question 33

Malignant tumour

Answer 33

Lose molecules on their surface that would normally hold them in place and can therefore be detached from their neighbours causing the cells to spread

Question 34

Benign tumour

Answer 34

Cancer cells continue to reproduce and form a mass of abnormal cells

Question 35

Other risk factors of developing cancer

Answer 35

``` Sun exposure Radiation exposure Chemicals Substances Viruses Bacteria Certain hormone Overweight Poor diet Drinking alcohol Smoking Born with damage to genes Activity levels ```

Question 36

What is a tumour

Answer 36

Swelling of a section of the body normally with no inflammation caused by an abnormal growth of tissue which can be benign or maligant

Question 37

How will a patient know if their cancer has spread

Answer 37

Cells can break away from a cancer and expand in the blood of lymphatic system to mainly anywhere in the body most types of cancer often expand to 1 or 2 places

Question 38

How can cancer be treated

Answer 38

Certain individuals diagnosed with cancer will only require a certain treatment however many individuals have a variety of treatments such as surgery, radiation therapy, chemotherapy, hormone therapy, targeted therapy, immune therapy, hormone therapy, clinical trials may be useful

Question 39

Why does cancer increase with age

Answer 39

Over along period of time the cells in our body can become damaged once the cells are damaged the cells may begin to grow and multiply more than normal forming a growth called a tumour which is the start of cancer

Question 40

What is the human body made of

Answer 40

Many specialised cells that perform specific functions

Question 41

What do specialised cells do

Answer 41

Have specific structural, functional and biochemical properties

Question 42

How do specialised cells arise

Answer 42

From differentiation of unspecialised cells during embryological development

Question 43

What is cellular differentiation

Answer 43

Under genetic control and involves cell signalling processes

Question 44

What happens during differentiation

Answer 44

Genes which express proteins important for the function of that cell remain switched on

Question 45

What happens once a cell becomes specialised

Answer 45

It stops dividing and only expresses the genes are characteristic for that type of cell

Question 46

Specialised cells

Answer 46

With similar functions are grouped into tissues systems and organs and similar organs are grouped into systems