Cells

Question 1

What are the main parts of a human/animal cell?

Answer 1

1. Nucleus
2. Cytoplasm
3. Cell Membrane
4. Mitochondria
5. Ribosomes

Question 2

What is the nucleus of a cell?

Answer 2

This contains the genetic material that controls the activities of the cell.

Question 3

What is the cytoplasm of a cell?

Answer 3

This is the surrounding hell like substance where most CHEMICAL REACTIONS take place- it controls ENZYMES that control these chemical reactions.

Question 4

What are Mitochondria in relation to cells?

Answer 4

These are where most of the reactions for respiration take place.

Respiration releases ENERGY that the cell needs to work.

Question 5

What are Ribosomes in relation to cells?

Answer 5

Ribosomes are where proteins are made in the cell.

Question 6

What is yeast?

Answer 6

Yeast is a single cel led organism which has a nucleus, cytoplasm, cell membrane and surrounded by a cell wall.

Question 7

Does a bacterial cell have a nucleus?

Answer 7

NO.

It has cytoplasm, cell membrane, cell wall but the GENETIC MATERIAL floats in the CYTOPLASM

Question 8

What is DIFFUSION?

Answer 8

Diffusionism the gradual movement of particles from places where there are lots of them to places where there are fewer of them.

Question 9

What is the OFFICIAL definition of DIFFUSION?

Answer 9

DIFFUSION is the spreading out of particles from an area of HIGH CONCENTRATION to an area of LOW CONCENTRATION.

Question 10

Does diffusion happen in liquids or gases?

Answer 10

BOTH.

Question 11

Does the difference in concentration between gases or liquids make a difference to the speed of diffusion.

Answer 11

YES.

The bigger the difference in concentration, the faster the DIFFUSION rate.

Question 12

Can diffusion happen in relation to cell membranes?

Answer 12

YES.

Cell membranes hold the cell together but they let stuff in and out of the cell.

HOWEVER, only very small molecules can diffuse through cell membranes like OXYGEN, GLUCOSE, AMINO ACIDS and WATER.

Question 13

Can large molecules diffuse through cell membranes?

Answer 13

NO.

Large molecules like starch and proteins can’t fit through the membrane.

Question 14

Name 4 specialist cells?

Answer 14

Palisade Leaf Cells
Guard Cells
Red Blood Cells
Sperm and Egg Cells

Question 15

Why are Palisade cells specialised?

Answer 15

Because they are adapted for photosynthesis

Question 16

How do palisade cells work?

Answer 16

They are packed with chloroplasts for photosynthesis at the top of the cell.

This means they are nearer the light.

They are also tall with a lot of surface area to absorb CO2.

Question 17

Why are guard cells specialist?

Answer 17

Because they are kidney shaped which opens and closes the stomata in a leaf.

Question 18

How do guard cells work?

Answer 18

When a plant has lots of water the guard cells fill with it and go plump and TURGID. This makes the stomata open so gases can be exchanged for photosynthesis.

When the plant is short of water the guard cells lose waters and become FLACCID making the stomata close. This helps stop too much water vapour escaping.

They’re also sensitive to light and close at night to save water without losing out on photosynthesis.

Guard cells therefore adapt their function allowing gas exchange and controlling water loss.

Question 19

How are red blood cells specialist?

Answer 19

They are adapted to carry oxygen.

Question 20

How are blood cells specially adapted?

Answer 20

Concave shape gives a big surface for absorbing oxygen.

They are packed with haemoglobin - pigment that absorbs the oxygen.

They have no nucleus to leave even more room for haemoglobin

Question 21

What are sperm and egg cells specialist for what role?

Answer 21

Reproduction

Question 22

How are sperm and egg specialist cells?

Answer 22

1. The main function of the egg cell carries female DNA and to nourish the developing embryo in the early stages.
2. When a sperm fuses with the egg, the egg’s membrane instantly changes its structure to stop any sperm getting in.
3. Sperm shaped for swimming - long tail, streamlined egg to help it swim.
4. Sperm carries enzymes in their heads to digest through the cell membrane.

Question 23

What is meant by differentiation?

Answer 23

It is the process where cells become specialised for a particular job

Question 24

What is a multicellular organism?

Answer 24

It is a human or dog or squirrel - it means where an organism has lots of specialist cells

Question 25

What is the word to describe the development of a multi-cellular organism?

Answer 25

Differentiation

Question 26

What is meant by tissue such as muscle tissue, heart tissue or brain tissue?

Answer 26

A tissue is a group of similar cells that work together to carry out a particular function

Question 27

Name three types of tissue in mammals?

Answer 27

1. MUSCULAR TISSUE - contracts (shortens) to move whatever is attached to it
2. GLANDULAR TISSUE - which makes and secretes chemicals like ENZYMES and HORMONES
3. EPITHELIAL TISSUE - covers some parts of the body like the inside of the gut

Question 28

What is meant by an organ system?

Answer 28

An organ system is a group of organs working together to perform a particular function

Question 29

Provide an example of an organ systems

Answer 29

DIGESTIVE SYSTEM:

1. Glands (pancreas and salivary glands provide digestive juices)
2. Stomach and small intestine which digest food
3. Liver produces bile
4. Small intestine which absorbs soluable food molecules
5. The large intestine absorbs water from undigested food