2a.1 - Cells

Question 1

What does the standard adult body cell contain?

Answer 1

• Nucleus
• Mitochondria
• Ribosomes
• Cytoplasm
• Cell membrane

Question 2

Why do cells need a nucleus?

Answer 2

Contains genetic material which control the activities of the cell

Question 3

Why do cells need cytoplasm?

Answer 3

Where most of the chemical reactions happen because it contains enzymes

Question 4

Why do cells need a cell membrane?

Answer 4

Holds the cell together and controls what goes in and out

Question 5

Why do cells need mitochondria?

Answer 5

Where most of the reactions for respiration take place. Respiration releases energy

Question 6

Why do cells need ribosomes?

Answer 6

Where proteins are made

Question 7

What features do plant cells have that animal cells don’t?

Answer 7

• Cell wall
• Vacuole
• Chloroplasts

Question 8

Why do plant cells need a cell wall?

Answer 8

Made of cellulose and it supports and strengthens the cell

Question 9

What is a vacuole?

Answer 9

Contains cell sap which is a weak solution of salts and sugar

Question 10

Why do plant cells need chloroplasts?

Answer 10

Contains a green substance called chlorophyll and is where photosynthesis happens which provides the cells with food

Question 11

What does a yeast cell contain?

Answer 11

• Cell membrane
• Cytoplasm
• Cell wall
• Nucleus

Question 12

What does a bacteria cell contain?

Answer 12

• Cell membrane
• Cell wall
• Cytoplasm
• Loose genetic material

Question 13

What is the definition of diffusion?

Answer 13

The spreading out of particles from an area of high concentration to an area of low concentration

Question 14

What can diffuse into and out of a cell membrane?

Answer 14

Oxygen, glucose, amino acids and water

Question 15

How are palisade cells adapted for photosynthesis?

Answer 15

• Lots of chloroplasts crammed near the top of the cells
• Tall so lots of surface area for absorbing CO2
• Thin so lots of palisade cells can fit at the top of the leaf

Question 16

What are guard cells adapted to do?

Answer 16

Open and close pores

Question 17

What do guard cells do when the plant has too much water?

Answer 17

• Guard cells become turgid. This makes the stomata open do gases can be exchanged for photosynthesis

Question 18

What do guard cells so when they don’t have enough water?

Answer 18

Guard cells lose water and become flaccid making the stomata close. This helps stop water vapour escaping

Question 19

How are guard cells adapted to open and close pores? (2)

Answer 19

• They are thin and have thick inner walls which makes the opening and closing work
• Sensitive to light and close at night to save water without losing out on photosyntheses

Question 20

How are red blood cells adapted to carry oxygen?

Answer 20

• Concave - big surface are for absorption
• Packed with haemoglobin - the pigment that absorbs oxygen
• No nucleus - more haemoglobin

Question 21

How are egg cells specialised for reproduction?

Answer 21

• Contain huge food reserves for the embryo

- When sperm fuses with the egg the cell membrane instantly changes to stop any more sperm

Question 22

How are sperm cells specialised for reproduction?

Answer 22

• Long tail and streamlined head to help it swim
• Lots of mitochondria to provide energy
• Carry enzymes to break up cell membrane

Question 23

What is differentiation?

Answer 23

The process where by which cells become specialised for a particular job

Question 24

What is a tissue?

Answer 24

A group of similar cells

Question 25

What do glands do? (e.g. the pancreas and salivary glands)

Answer 25

Produce digestive juices

Question 26

What does the stomach and the small intestine do?

Answer 26

Digest food

Question 27

What does the liver do?

Answer 27

Produces bile

Question 28

What does the large intestine do?

Answer 28

Absorb water from undigested food