B1 - Cell Structure and Transport

Question 1

B1 - Which organelles are present in an animal cell?

Answer 1

Nucleus
Cell membrane
Cytoplasm
Mitochondria (respiration)
Ribosome (protein synthesis)

Question 2

B1 - Which organelles are present in a plant cell?

Answer 2

Nucleus
Cell membrane
Cytoplasm
Mitochondria (respiration)
Ribosome (protein synthesis)
Chloroplasts
Vacuole
Cell wall

Question 3

B1 - How do you calculate the magnification of an object?

Answer 3

Magnification = Size of image/ Size of real object

Question 4

B1 - What is osmosis?

Answer 4

• The diffusion (movement) of water from a dilute to concentrated solution.
• Across a partially permeable membrane.
• Dilute solutions have lots of water, concentrated solutions have lots of solutes (not very much water).

Question 5

B1 - What does hypertonic mean?

Answer 5

Concentrated solution outside the cell (water will move out, cell will shrivel).

Question 6

B1 - What does hypotonic mean?

Answer 6

Concentrated solution inside the cell (water will move in, cell will bulge/burst).

Question 7

B1 - What does isotonic mean?

Answer 7

Same concentration inside and outside the cell (no net movement, cell will stay the same size).

Question 8

B1 - What is diffusion?

Answer 8

• The spreading of particles in solution or particles of a gas.
• From an area of high to low concentration.
• It is a passive process - does not require energy

Question 9

B1 - What is active transport?

Answer 9

• Movement of substances from a more low to high concentration (against a concentration gradient).
• This requires energy from respiration.
• Involves carrier (or transport) proteins.

Question 10

B1 - Describe and explain how the alveoli are adapted for efficient gas exchange.

Answer 10

Description = Explanation

Lots of alveoli = large surface area.

One cell thick = short distance for diffusion.

Good blood supply = maintains a steep
concentration gradient.