Chapter 1 - Cells

Question 1

Name a difference between an animal and a plant cell:

Answer 1

Plant cell has: chloroplasts/vacuole/cell wall

Question 2

Name two specialised cells and two of their adaptions

Answer 2

Sperm cell - Acrosome contains enzymes so the tail can move faster
Root hair cell - Increases surface area so that there’s more space for plants to absorb nutrients
Cilia cell - Has tiny hairs to move dust and mucus from the lungs

Question 3

What is a tissue?

Answer 3

A group of similar cells that perform a specialised function

Question 4

What is an organ?

Answer 4

A part of the body with a specialised function.

Question 5

What is the organ system?

Answer 5

A group of organs that work together to perform a function.

Question 6

Define ‘diffusion’

Answer 6

The random NET movement of particles from a high to low concentration.

Question 7

How is diffusion increased?

Answer 7

Stirring
Heat
Surface Area

Question 8

How is diffusion slowed down?

Answer 8

• Lower temperature
• More area to diffuse
• Smaller concentration gradient

Question 9

How does diffusion of O2 occur in breathing?

Answer 9

In the alveoli.
O2 has low concentration in the blood and high concentration in the airspace.
It diffuses from high to low (into the blood)

Question 10

Define ‘organelle’

Answer 10

The structures within a cell

Question 11

What is the endocrine system for?

Answer 11

The production of hormones.

Question 12

Where conditions allow for faster diffusion?

Answer 12

• Large surface area
• Large blood supply
• Thin cell
• Small distance = faster diffustion

Question 13

How does diffusion occur in nerve cells?

Answer 13

• (electrical) impulse is converted into a chemical signal (at the synapse)
• Neurotransmitter released from one neurone into a synapse
• they diffuse across the gap, towards the next neurone’s receptors
• moving from a high concentration to low concentration
• binding converts the chemical signal to an (electrical) impulse

Question 14

How does diffusion occur in digestion?

Answer 14

• breaks down large food molecules into smaller SOLUBLE molecules (e.g. glucose, amino acids, and fatty acids easily absorbed)
• diffuse across intestine wall into bloodstream
• Small intestines have villi
• Villi: increase SA (surface area) of small intestines = more substances absorbed through diffusion
• Villi have lots of capillary= good blood supply. molecules go straight to bloodstream (when diffused)

Question 15

What are the adaptations of a root hair cell?

Answer 15

• Increases surface area of root

- No chloroplasts

Question 16

What are the adaptations of a palisade cell?

Answer 16

• Packed with chloroplasts for photosynthesis

- At the top of the leaf

Question 17

What are the adaptations of a sperm cell?

Answer 17

• Vacuole has enzymes to break the surface of the egg cell
• Nucleus has half of the father’s chromosomes
• Has a filament (tail) for movement
• Contains a large number of mitochondria for energy release

Question 18

What happens when a plant doesn’t get enough water?

Answer 18

Because the vacuole shrinks, the plant shrivels and wilts. The cell wall separates from the cell membrane. This is called PLASMOLYSIS

Question 19

Name a similarity between an animal cell and a plant cell.

Answer 19

-both have a cell membrane/cytoplasm/ribsomes/mitchondria/nucleus

Question 20

Give two differences between an animal cell and the cell of a bacterium.

Answer 20

• Bacterium has a flagellum to help it move

- Animal cells have a nucleus

Question 21

Why do sperms need many mitochondria?

Answer 21

Sperm cells need a lot of energy to swim

Question 22

What is the main job of a leaf mesophyll cell?

Answer 22

Allows photosynthesis to take place

Question 23

Explain one way in which the structure of the leaf mesophyll cell helps is to carry out its job

Answer 23

It has a large surface area so it can more sunlight. Photosynthesis can happen faster

Question 24

What is the function of the nucleus?

Answer 24

nucleus - controls activity of the cell. contains DNA

Question 25

What is the function of the cell membrane?

Answer 25

cell membrane - controls what goes in and out of the cell

Question 26

What is the function of the chloroplasts?

Answer 26

chloroplasts - responsible for the process of photosynthesis

Question 27

What is the function of the cell wall?

Answer 27

cell wall - cell structure

Question 28

How does diffusion of CO2 occur in breathing?

Answer 28

In the alveoli.
CO2 has high concentration in the blood and low concentration in the airspace.
It diffuses from high to low (into the airspace)

Question 29

What is the function of the mitochondria?

Answer 29

mitochondria - releases energy through respiration

Question 30

What is the function of the cytoplasm?

Answer 30

cytoplasm - where chemical reactions take place

Question 31

What is the function of the cell wall?

Answer 31

cell wall - cell structure

Question 32

How does diffusion of CO2 occur in breathing?

Answer 32

In the alveoli.
CO2 has high concentration in the blood and low concentration in the airspace.
It diffuses from high to low (into the airspace)

Question 33

What happens to an animal cell in a hypertonic solution?

Answer 33

it shrivels

Question 34

What happens to an animal cell in a hypotonic solution?

Answer 34

lysis (bursts)

Question 35

What happens to an plant cell in a hypertonic solution?

Answer 35

plasmolysis (cell membrane separates from cell wall)