B2.1

Question 1

What are the main structures in an animal cell and what are their functions?

Answer 1

Nucleus- contains DNA and controls activities of the cell
Cell membrane- controls passage of substances
Cytoplasm- jelly like substance that chemical reactions take place in
Mitochondria- release and uses energy from respiration
Ribosomes- where protein synthesis takes place

Question 2

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

Answer 2

Cellulose cell wall- keeps the structure of cell and keeps it together
Chloroplast- contains chlorophyll which absorbs light energy to make its own food via photosynthesis
Vacuole- sac that contains cell sap which keeps the cell rigid to support the plant

Question 3

What happens when you culture bacteria on an agar plate?

Answer 3

You grow many millions of bacteria.

Question 4

What are the 3 structures in a bacteria cell that isn’t in a plant/animal cell?

Answer 4

Plasmids
Slime capsule
Genetic material

Question 5

How do yeast cells reproduce and why are they specialised?

Answer 5

Reproduce by asexual budding.

Specialised to be able to survive for longer when there isn’t a lot of oxygen.

Question 6

When yeast cells use oxygen for aerobic respiration, what does it break down?

Answer 6

Oxygen breaks down the sugar to provide energy for the cell.

Question 7

During aerobic respiration in yeast cells, what do they produce?

Answer 7

Water and carbon dioxide.

Question 8

What is respiration of yeast called?

Answer 8

Fermentation.

Question 9

Why are some cells specialised?

Answer 9

In order to carry out particular jobs.

Question 10

What happens to a cell when it becomes specialised?

Answer 10

It’s structure is adapted to suit the particular job it does.

Question 11

Root hair cells:
Advantage of root hair cells?
What does the xylem tissue do?

Answer 11

Helps them to take up water more efficiently.

Xylem tissue carries water and mineral ions to the plant.

Question 12

Two main adaptations of root hair cells:

Answer 12

• increase the surface area for water to move into the cell

- large permanent vacuole that speeds up the movement of water by osmosis

Question 13

Sperm cells:
Advantage of a sperm cell?
What does it have to do?

Answer 13

They contain genetic information of the male.

Has to move through water then break into the egg.

Question 14

What are the main functions of a sperm cell?

Answer 14

• long tail helps to move
• full of mitochondria which provides energy for the tail to work
• acrosome stores digestive enzymes for breaking down the outer layers of the egg
• ledge nucleus which contains genetic information

Question 15

Cone cells:
Advantage of a cone cell?
Where is it placed?

Answer 15

They make it possible to see in colour.

In the light-sensitive layer of the eye (retina).

Question 16

Main functions of a cone cell:

Answer 16

• outer segment contains a special chemical which changes chemically in coloured light
• mitochondria which releases energy to reform the visual pigment
• specialised synapse that connects to the optic nerve which triggers when visual pigment changes

Question 17

What is diffusion?

Answer 17

Particles of a gas spreading out which results in the net movement of particles.

Question 18

What is a net movement in diffusion?

Answer 18

Particles moving from a high concentration to a low concentration.

Question 19

When will diffusion take place quickly?

Answer 19

When there is a big difference in concentration between two areas.

Question 20

What is the equation for net movement?

Answer 20

net movement=particles moving in-particles moving out

Question 21

What is the difference between two areas of concentration called?

Answer 21

Concentration gradient.

Question 22

What effects the rate of diffusion?

Answer 22

Temperature

Concentration gradient

Question 23

How does the temperature effect the rate of diffusion?

Answer 23

Increase in temperature means the particles in a gas or a solution move quicker.
This increases the rate of diffusion.

Question 24

What is a tissue?

What is an organ?

Answer 24

Group of cells with similar structure and function working together.
Organs are made up of tissues which work together.

Question 25

Give 3 animal/human tissues and their function:

Answer 25

Muscular tissue-contracts to bring about movement
Glandular tissue-contains cells that can produce substances such as enzymes and hormones
Epithelial tissue-covers outside of the body as well as internal organs

Question 26

Give 3 plant tissues and their functions:

Answer 26

Epidermal tissue-covers the surfaces and protect them
Mesophyll tissue-contains lots of chloroplast and can carry out photosynthesis
Xylem and phloem tissue-transports water and dissolved minerals and food

Question 27

What are organs made up of? Give an example

Answer 27

Made up of tissues which all work together.

Stomach digests the food.

Question 28

Functions of the 3 tissues in a stomach:

Answer 28

Muscular tissue-churns the food and digestive juices
Glandular tissue-produces digestive juices that break down food
Epithelial tissue-covers the inside and outside of the organ

Question 29

What is an organ system?

What do they do?

Answer 29

Organs working together.

Transport blood or digest food.

Question 30

What is the function of the digestive system?

Answer 30

Exchanges food substances with the environment.

Question 31

What is made up of insoluble molecules?

Answer 31

Foods that we take in and eat.

Question 32

Why do the insoluble molecules have to be broken down and what does it form?

Answer 32

The body cannot absorb and use the molecules.

They are broken down into smaller, soluble molecules.

Question 33

What are the two main organs where food is digested?

Answer 33

Stomach and small intestine.

Question 34

What are the 3 main organs in a plant and their function?

Answer 34

Roots-take up water and minerals from soil
Stem-supports leaves and flowers
Leaf-carries out photosynthesis