Cell Biology Paper 1

Question 1

Why are cells specialised?

Answer 1

To perform a specific function

Question 2

What is xylem cells function?

Answer 2

Transport water UP the plant

Question 3

What are pholem cells function?

Answer 3

Transport SUGAR UP AND DOWN the plant

Question 4

what is a stem cell?

Answer 4

A cell that has the ability to differentiate into different specialised cells

Question 5

What is an embryonic stem cell?

Answer 5

A stem cell that can differentiate into any type of cell

Question 6

Where are stem cells found?

Answer 6

Bone marrow tissue

Question 7

What can stems cells be used for?

Answer 7

• Repair damaged organs
• Grow new tissue

Question 8

What can embryonic stem cells be used for?

Answer 8

Therapeutic cloning

Question 9

What is therapeutic cloning?

Answer 9

Creating an embryo (from patient) so embryonic stem cells are taken and used in the patient’s body

Question 10

Why are embryonic stem cells controversial?

Answer 10

This is because they have the potential to be human

Question 11

What does it mean to be multipotent?

Answer 11

The ability to differentiate into multiple types of specialised cells

Question 12

What does it mean to be pluripotent?

Answer 12

The ability to differentiate into all types of specialised cells

Question 13

What are the 2 functions of stem cells?

Answer 13

Self renew (mitosis)
Differentiate

Question 14

What is differentiation?

Answer 14

The process of a stem cell becoming a specialised cell

Question 15

Where are embryonic stem cells found?

Answer 15

Fertilisation (blastocyst)

Question 16

What is the cell cycle? (3 steps)

Answer 16

1) cells grows and replication of DNA/chromosomes
2) mitosis (nucleus divides) and one set of chromosomes go to each end of cell
3) cell (cytoplasm and cell membranes) divides to form 2 cells

Question 17

What does totipotent mean?

Answer 17

The ability (under the right conditions) for an embryonic stem cell to generate a viable embryo

Question 18

What is mitosis?

Answer 18

Cell division into 2 genetically identical daughter cells

Question 19

What is meiosis?

Answer 19

Cell division into 4 gametes

Question 20

What are disadvantages to using stem cells in leukaemia?

Answer 20

Donor has to be compatible, or WBCs will attack cells
Culture (virus) bone marrow might be present

Question 21

What chemical is genetic material made from?

Answer 21

DNA

Question 22

Chromosomes always come in ____?

Answer 22

Pairs

Question 23

What is the function of DNA?

Answer 23

It is a chemical that codes for specific proteins

Question 24

What is the formula for magnification?

Answer 24

Image size / real size

Question 25

Give two aseptic techniques and explain why u need to do it?

Answer 25

Use disinfectant to wipe down surfaces to prevent contamination from other bacterium
Flame neck of the culture of bacterium bottle with bunsen burner so bacterium is killed preventing outside contamination

Question 26

What can be used to grow bacterium?

Answer 26

• Agar gel in a Petri dish
• Nutrient broth

Question 27

Why must you sterilise an inoculating loop?

Answer 27

To kill other microorganisms to reduce risks of contamination

Question 28

What is transpiration?

Answer 28

The loss of water from the plant

Question 29

Where does transpiration occur?

Answer 29

In the leaves

Question 30

What affects the rate of transpiration? How?

Answer 30

Light intensity (higher than higher rate)
Temperature (warmer than higher rate)
Air flow ( better air flow than higher rate due to water vapour swept away)
Humidity (less than higher rate)

Question 31

What is the first stage in the cell cycle?

Answer 31

Sub cellular structures, replicate and so do DNA

Question 32

What is the second stage of the cell cycle?

Answer 32

One set of chromosomes is pulled to each end of the cell

Question 33

What happens at stage three of the cell cycle?

Answer 33

The cell membrane and cytoplasm divides to form two new cells 

Question 34

What happens when a guard cell goes flaccid (lose)?

Answer 34

Close stomata to stop water loss

Question 35

What happens when guard cells turgid (plump)?

Answer 35

Stomata opens for gas exchange for photosynthesis