Cell Biology

Question 1

Nucleus

Answer 1

1. Contains genetic material

2. Controls the actions of a cell

Question 2

Cytoplasm

Answer 2

Where chemical reactions occur

Question 3

Cell membrane

Answer 3

Controls passage of substances in and out of cells

Question 4

Mitochondria

Answer 4

Where aerobic respiration occurs

Question 5

Ribosomes

Answer 5

Where proteins are synthesized (protein synthesis)

Question 6

Which 3 structures are found in plant but not animal cells?

Answer 6

1. Cell wall
2. Permanent Vacuole
3. Chloroplast

Question 7

Cell wall

Answer 7

1. Made of cellulose

2. Strengthens the cell

Question 8

Permanent Vacuole

Answer 8

1. Filled with cell sap

2. Supports the plant

Question 9

Chloroplast

Answer 9

1. Contains Chlorophyll

2. Absorb light to make glucose through photosynthesis

Question 10

Examples of Eukaryotic cells

Answer 10

Plant, animal and fungal cells

Question 11

Examples of Prokaryotic cells

Answer 11

Bacterial cells

Question 12

What are the 3 differences between prokaryote and eukaryote?

Answer 12

Prokaryotes:

1. Are smaller
2. do not contain mitochondia or chloroplasts
3. Do not have DNA enclosed in a nucleus (Plasmids)

Question 13

Plasmids

Answer 13

1. Loops of DNA that can be transferred between cells

2. Allows bacterial cells to move genes

Question 14

Flagella

Answer 14

Tail like structures which help bacteria cells move

Question 15

Resolution

Answer 15

The ability to see two or more objects as seperate

Question 16

Why are Electron microscopes better than light microscopes? [3]

Answer 16

1. Passes electrons => much better resolution
2. Higher magnification
3. Fine detail
4. Can see sub cellular structures and organelles

Question 17

Formula for Magnification

Answer 17

Magnification= image size/ actual size

Question 18

Where are genes found in a cell?

Answer 18

Genes are found in DNA, which build up chromosomes, found in the Nucleus of a cell

Question 19

How many pairs of chromosomes do Humans have?

Answer 19

23 pairs

Question 20

Describe the process of Mitosis

Answer 20

1. One set of Chromosomes pulled to each end of the cell
2. Nucleus divides
3. Cytoplasm and Cell membranes divide to form two identical cells

Question 21

Why is Mitosis important? [3]

Answer 21

Provides cells for:

1. Growth and development of multicellular organisms
2. Repairing damaged tissues
3. Asexual reproduction

Question 22

Stem cells

Answer 22

Undifferentiated cells which can divide to specialize into different types of cells

Question 23

Embryonic Stem cells

Answer 23

1. Found in human embryos

2. Can specialize into all different types of cells

Question 24

Adult Stem cells

Answer 24

1. Found in Organs and tissues such as bone marrow

2. Limited range of specializations

Question 25

What is the use of Stem cells?

Answer 25

Treating conditions caused by cell damage, e.g. Diabetes and paralysis by replacing them

Question 26

Therapeutic cloning

Answer 26

To get Stem cells from cloned embryos

Question 27

What are the objections to Stem cell treatment?

Answer 27

1. Ethical/ religious, e.g. lack of consent from embryo | 2. Risk of viral infection transfer

Question 28

Describe the sources and uses of Stem Cells in plants

Answer 28

1. Found in Meristems 2. Allow plants to make cells for growth 2. Can be used to clone plants

Question 29

Why are some plants cloned?

Answer 29

1. To protect a rare species from extinction | 2. Large numbers of identical crop plants with features, e.g. disease resistance can be made

Question 30

Diffusion

Answer 30

Movement of particles from an area of high concentration to low concentration

Question 31

Examples of Diffusion

Answer 31

Oxygen in the alveoli (high conc) to blood (low conc)

Question 32

What are the 3 factors affecting rate of diffusion?

Answer 32

1. Concentration gradient 2. Temperature (high= faster) 3. Surface area (large SA= faster diffusion)

Question 33

Osmosis

Answer 33

Movement of water particles from an area of high concentration to an area of low concentration across a semi-permeable membrane

Question 34

Active Transport

Answer 34

Movement of substances from areas of low concentration to high concentration (against the concentration gradient) using energy from respiration

Question 35

Examples of Active Transport

Answer 35

1. Allows mineral ions to be absorbed by plants 2, Root hair cells 2. Gut/ kidney tubules to blood

Question 36

Therapeutic Cloning Method [7]

Answer 36

1. . Human egg cell from a donor is collected ​ 2. Remove and discard the nucleus from the egg cell ​ 3. Remove a body cell from the patient and extract the nucleus ​ 4. Nucleus is placed into empty egg cell ​ 5. Cells divide by mitosis and form an embryo ​ 6. Cells will differentiate to form organs ​ 7. Organ can now be used for transplant

Question 37

Disadvantages of Therapeutic Cloning

Answer 37

1. high cost 2. some cells mutate and cause tumours in patients 3. extracting eggs = costly and painful

Question 38

Advantages of adult stem cells

Answer 38

1. no risk or damage to embryos 2. relatively safe procedure 3. adults can give consent 4. more reliable technique

Question 39

Advantages of embryonic stem cells

Answer 39

1. can specialize into any type of tissue to help treat diseases 2. safe cost for drug development 3. painless procedure 4. can grow large numbers of embryos in lab

Question 40

disadvantages of adult stem cell

Answer 40

1. risk of infection from procedure 2. painful procedure 3. only used to treat some diseases

Question 41

disadvantages of embryonic stem cell

Answer 41

1. no consent from embryos 2. cells can grow out of control = cancer 3. may be rejected by the body 4. patients must takes drugs for the rest of their lives 5. transfer of viral infection

Question 42

Advantages of Therapeutic Cloning

Answer 42

1. no tissue rejection 2. no donor needed= no long waiting time 3. potential to create organs