B2

Question 1

What does the nucleus carry?

Answer 1

The chromosomes

Question 2

What do the chromosomes carry?

Answer 2

Genes

Question 3

What do the genes contain?

Answer 3

Instructions for making new cells

Question 4

What is a gene?

Answer 4

Small packet of information that controls the characteristics of your body. Unique molecule that makes up chromosomes.

Question 5

How many genes do chromosomes carry?

Answer 5

Could carry several hundred or even thousand genes.

Question 6

How many chromosomes per cell?

Answer 6

• 46 chromosomes, 23 pairs
• 1 from father
• 1 from mother

Question 7

What is mitosis?

Answer 7

Stage in cell cycle that divides the nucleus to create identicla daughter cells.

Question 8

Why identical cells are necessary ?

Answer 8

Same genetic material is needed in every cell.

Question 9

How do asexual production produce offspring?

Answer 9

Mitosis

Question 10

How long is the cell cycle?

Answer 10

Tim varies can be less than 24 hours or could take several years.

Question 11

When is the cell cycle the fastest?

Answer 11

Embryonic stage.

Question 12

Is the cell cycle fast during childhood?

Answer 12

Yes remain fairly rapid during childhood , as they are growing.

Question 13

What happens to the cell cycle when puberty is over?

Answer 13

Slows down

Question 14

What happens to the cell cycle when you are an adult ?

Answer 14

Only for repair and replacement , rather than growth.

Question 15

What cells can get replaced?

Answer 15

Hair follicles , skin , blood , lining of digestive system.

Question 16

STAGE 1 of the cell cycle , what is it?

Answer 16

Interphase: cell grows in size , DNA and organelles replicate (ribosomes and mitochondria), forms two copies of each chromosome.

Question 17

STAGE 2 of the cell cycle , what is it ?

Answer 17

Mitosis: replicated chromosomes line up along the centre and get pulled to opposite poles. The nucleus divides.

Question 18

STAGE 3 of the cell cycle, what is it ?

Answer 18

Cytokinesis: cell membrane and cytoplasm divide to form 2 new identical daughter cells.

Question 19

Why is the cell cycle important?

Answer 19

For the growth and development of multicellular organisms

Question 20

How many cells in the body?

Answer 20

37.2 trillion

Question 21

What is the state of all cells in early development of both animal and plant embryos?

Answer 21

Unspecialised

Question 22

What is the common name for unspecialised cells?

Answer 22

Stem cells.

Question 23

What is the state of the majority of cells in an animal by the time a baby is born?

Answer 23

Specialised

Question 24

Examples of specialised cells ?

Answer 24

• skin cells
• nerve cells
• muscle cells

Question 25

What is the definition of a specialised cell?

Answer 25

An adapted , differentiated cell with characteristics to perform a particular function.

Question 26

How does the stem cells population increase?

Answer 26

Divide through mitosis

Question 27

What cells can not divide?

Answer 27

- skin | - red blood cells

Question 28

What happens if a cell cannot divide?

Answer 28

Adult stem cells replace them

Question 29

What are mature animals cells limited to?

Answer 29

Repair and replacement

Question 30

What happens usually if a nerve cell gets damaged?

Answer 30

It is permanently damaged , and can cause paralysis

Question 31

What is the difference between animals and plant cells in terms of differentiation?

Answer 31

Plant cells differentiate throughout their lives, animal cells do not

Question 32

Where are stem cells found on a plant?

Answer 32

The meristem

Question 33

Where does active transport take place continuously on plants?

Answer 33

Root hair cells

Question 34

Do plants grow all throughout their lives?

Answer 34

Yes,

Question 35

Can plant cells redifferentiate?

Answer 35

Yes, they differentiate when in final position , then can redifferentiate at any time

Question 36

What can you do with a small cell from a plant?

Answer 36

Move it to a different area and it will redifferentiate.

Question 37

What is cloning?

Answer 37

Producing identical offspring

Question 38

How you can clone plants?

Answer 38

Take small part of leaf , it will become unspecialised and go through mitosis new cells will differentiate into the xylem , phloem , photosynthesis and root hair cells need to form a new plant.

Question 39

Why is it difficult to clone animals ?

Answer 39

Animal cells are permanently differentiated.

Question 40

What is a stem cell?

Answer 40

An undifferentiated cell of an organism which is capable of giving rise to many more cells of the same type , and from which certain other cells can arise from differentiation.

Question 41

What is a zygote?

Answer 41

The single cell formed when an egg and sperm meet.

Question 42

Where are adult stem cells commonly found in humans?

Answer 42

Bone marrow

Question 43

Where are the embryonic stem cells found?

Answer 43

After zygote cell divides into a hollow ball of cells. Inside the that ball are the embryonic stem cells that differentiate to form a specialised cell.

Question 44

What is the main purpose for adult stem cells?

Answer 44

To stay in tissues for repair and replacement

Question 45

What are examples of conditions that are down to cells not working and not being able to repair of replace?

Answer 45

- spinal injuries can cause paralysis as spinal nerves can not replace themselves - type 1 diabetes inject insulin because specialised cells in the pancreas do not work

Question 46

Why stem cell research is important?

Answer 46

If cells could dedifferentiate, it could save millions of lives.

Question 47

How plant clones can be made ?

Answer 47

Take stem cells from the meristem .

Question 48

Why stem cells research is important in plants?

Answer 48

- helps produce large numbers of rare plants - can also study effects of cloning - can clone disease resistant plants.

Question 49

Advantages of embryonic stem cells?

Answer 49

- has potential to develop into any thpe of cell /tissue - used to treat humans disease - painless

Question 50

Disadvantages of embryonic stem cells?

Answer 50

- unethical-embryos cannot give permission - possible harm/death to embryo - can transfer viral infection.

Question 51

Advantages of adult stem cells?

Answer 51

- plentiful supply - no ethical, issues - well tried and tested

Question 52

Disadvantages of adult stem cells?

Answer 52

- painful to extract - fewer diseases can be treated - can only form the type of cells as the tissue they were taken from.

Question 53

What is therapeutic cloning?

Answer 53

An embryo is produced with the same genes as the patient, stem cells from the embryo are not rejected by the patients body so they may be used for medic,a treatment.

Question 54

What conditions are stem cell research helping?

Answer 54

- spinal cord injuries - diabetes - heart attack - blindness - damaged bones