Unit 1 - Cell Biology

Question 1

What does the nucleus do

Answer 1

Control cell activities, contains DNA

Question 2

What does the cytoplasm do

Answer 2

It’s where chemical reactions take place

Question 3

What does the cell membrane do

Answer 3

Controls what goes in and out of a cell

Question 4

What do the ribosomes do

Answer 4

Make proteins from amino acids (protein synthesis)

Question 5

What do the mitochondria do

Answer 5

Release energy from respiration

Question 6

What is the cell wall for

Answer 6

For strength/support, made from cellulose (eukaryotes only)

Question 7

What does the vacuole contain

Answer 7

Cell sap

Question 8

What do chloroplasts do

Answer 8

Contain chlorophyll for photosynthesis

Question 9

What is a plasmid

Answer 9

Small ring of DNA

Question 10

Name 3 specialised animal cells

Answer 10

Nerve, muscle, and sperm cells

Question 11

Name 3 specialised plant cells

Answer 11

Xylem, phloem, root hair cells

Question 12

How are nerve cells adapted for its function

Answer 12

Insulation - speeds up electrical impulses carried by the axon

Question 13

How are sperm cells adapted for its function

Answer 13

Tail - so it can swim
Mitochondria - releases energy for swimming

Question 14

How are xylems adapted for its function

Answer 14

No end plates or cytoplasm - to carry more water
Strengthened with lignin for support

Question 15

How are phloems adapted for its function

Answer 15

End plates have pores - to allow dissolved substances through
Companion cells - provide energy for transporting sugars

Question 16

How are root hair cells adapted for its function

Answer 16

Large surface area - to increase rate of absorption
Lots of mitochondria - to provide energy for active transport

Question 17

Magnification formula

Answer 17

Magnification = Image size / Actual size

Question 18

Where are stem cells found

Answer 18

Animals - bone marrow
Plants - meristem tissue

Question 19

What is therapeutic cloning

Answer 19

• Get your patient’s body cell and a human egg cell
• Separate the nucleus from both cells
• Put the patient’s nucleus into the egg cell
  This is used for medical treatment

Question 20

What is diffusion

Answer 20

Particles moving from an area of high concentration to low concentration

Question 21

Where does diffusion happen in the human body

Answer 21

• Oxygen diffuses from the blood into cells
• Carbon dioxide diffuses out of the cells into the blood
• Urea (waste product) diffuses out of cells

Question 22

What factors affect diffusion

Answer 22

• Concentration gradient
• Temperature
• Surface area of the membrane (bigger surface area = faster diffusion)

Question 23

What is active transport

Answer 23

Movement of particles from low to high concentration using energy (from respiration)

Question 24

Where does active transport happen

Answer 24

• Sugar absorption in the small intestine
• Mineral ions in root hair cells

Question 25

How is the small intestine adapted for exchange

Answer 25

Lined with villi/microvilli
- Increases surface area
- Have thin walls for short diffusion distance
- Microvilli have many mitochondria to provide energy for active transport

Question 26

How are lungs adapted for exchange

Answer 26

• Many alveoli (large surface area for gas exchange
• Thin alveoli walls (short diffusion distance)
• Lungs are ventilated (brings fresh oxygen) to maintain concentration gradient

Question 27

What is osmosis

Answer 27

Diffusion of water from dilute to concentrated solution through a partially permeable membrane

Question 28

Why don’t plant cells burst during osmosis

Answer 28

They have a cell wall