Cells (specialisation and diffusion)

Question 1

Palisade leaf cells are adapted for photosynthesis.

1. They are packed with …. for photosynthesis, more crammed at the top so they’re nearer the light.
2. They are …. which means they have a large surface area exposed down the side for absorbing CO2 from the air in the leaf.
3. A … shape means that you can pack loads of them at the top of a leaf.

Answer 1

1. They are packed with chloroplasts for photo photosynthesis.
2. They are tall which means they have a large surface area exposed down the side for absorbing CO2 from the air in the leaf.
3. A thin shape means that you can pack loads of them at the top of a leaf.

Question 2

Where are palisade leaf cells found?

Answer 2

Grouped together at the top of the leaf where the most photosynthesis happens.

Question 3

What are the 3 main functions of the egg cell?

Answer 3

To carry the female DNA.

To nourish the developing embryo in the early stages.

It also contains huge food reserves to feed the embryo.

Question 4

Palisade leaf cells are adapted for…. .

Answer 4

Palisade leaf cells are adapted for photosynthesis.

Question 5

Give an example of an organ system and describe it…

1. The system and overall function
2. Organs it’s made up of and functions (5)

How does this system interact with the envrinoment?

Answer 5

The digestive system for breaking down food to extract nutrients

1. Glands (slaivary and the pancreas) produce digestive juices
2. The stomach and small intestine digest food
3. The liver which produces bile
4. The small intestine absorbs soluble food molecules.
5. The large intestine absorbs water from undigested food leaving faeces.

It exchanges materials by taking in nutrients and releasing substances such as bile.

Question 6

1/5 in an animal cell - contains genetic material that controls the activities of the cell.

Answer 6

Nucleus

Question 6

Name two single celled microorganisms.

Answer 6

Yeast and Bacterial Cells

Question 6

What is a partially permeable membrane?

Answer 6

A membrane with small gaps in it, which holds its structure, but allows small molecules to diffuse through it.

Question 7

How is the sperm cell adapted to make sure it gets its DNA to the female DNA?

(swimming, 2, energy, and fusion)

Answer 7

It has a long tail and a stream lined head, to help it swim to the egg.

There are a lot of mitochondria in the cell to make sure it gets the energy it needs.

They carry enzymes in their heads to digest through the cell membrane.

Question 8

What is diffusion?

Answer 8

Diffusion is the spreading out of particles from an area of high concentration to an area of low concentration.

Question 8

What is differentiation?

Answer 8

Differentiation is the process by which cells become specialised for a particular job.

Question 9

What affects the rate of diffusion down the concentration gradient?

Answer 9

Temperature

Difference in concentrations

Surface area of the diffusion surface

Distance travelled

Question 11

A bacterial cell has … and a cell … surrounded by a cell … . The genetic material floats in the … because bacterial cells don’t have a … . Draw the bacterial cell.

Answer 11

A bacterial cell has cytoplasm and a cell membrane surrounded by a cell wall. The genetic material floats in the cytoplasm because bacterial cells don’t have a nucleus.

Question 12

How does the egg cell make sure the offspring get the right amount of DNA?

Answer 12

The membrane changes shape as soon as a sperm cell has fused with it. This stops any more sperm getting in.

Question 13

2/3 in a plant cell - these are where photosynthesis occurs, which makes food for the plant. They contain a green substance called chlorophyll.

Answer 13

Chloroplasts

Question 15

A yeast cell has a … (containing genetic material), …, and a cell …, surrounded by a cell … . Draw the yeast cell.

Answer 15

A yeast cell has a nucleus (containing genetic material), cytoplasm, and a cell membrane, surrounded by a cell wall.

Question 15

What states does diffusion happen in?

Answer 15

Diffusion happens in both solutions and gases, because in these substances particles can move around more freely.

Question 15

The bigger the difference in … the faster the diffusion rate. When different gases diffuse through eachother, like when perfume is sprayed in a room.

Answer 15

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

Question 16

3/5 in an animal cell - holds the cell together and controls what goes in and out.

Answer 16

Cell membrane

Question 17

What is haemoglobin?

What is missing in the cell to make room for more of this?

Answer 17

It is a pigment carried by red blood cells because it absorbs oxygen.

There is no nucleus to make more room for the haemoglobin.

Question 18

So what are the guard cells adapted to do? (2 marks)

G

W

Answer 18

They are adapted to their function in…

1. allowing gas exchange

and

2. controlling water loss

within a leaf.

Question 19

What are the advantages of the red blood cells’ concave shape? (2)

Answer 19

1. Gives them a big surface area for absorbing oxygen
2. Helps them pass smoothly through capilleries to reach body cells.

Question 20

1/3 in a plant cell - made of cellulose, it supports the cell and strengthens it.

Answer 20

Rigid cell wall

Question 20

What happens to the specialised cells in systems etc?

1.

2.

3.

What is 3 used for in large multicellular organisms?

Answer 20

The specialised cells form tissues.

A few of these form oragns.

A few of these form organ systems.

In large multicelluar organisms, there are different organ systems to exchange and transport materials.

Question 21

Which cells are specially adapted for reproducing?

Answer 21

Sperm and egg cells, gemates.

Question 21

What are organs made of? ... for example the stomach

Answer 21

A group of different tissues that work together to perform a particular function.

Question 23

Why do partciles flow through the membrane? How do they move?

Answer 23

Because on one side there is a high concentration and on the other, a low concentration. They move randomly, but they spread to reach equilibrium.

Question 24

What do specialised cells do?

Answer 24

They carry out a particular function.

Question 26

When do guard cells do when the plant has lots of water?

Answer 26

The guard cells fill with water and go *turgid,* making them open so gases can be exchanged for photosynthesis.

Question 27

How do dissolved substances move in and out of cells?

Answer 27

Diffusion.

Question 29

What size and type of molecules diffuse through cell membranes? O, G, AA, W S and P can't fit through.

Answer 29

Only very small molecules can diffuse through cell membranes. Oxygen, glucose, amino acids, and water. Bigger molecules like startch and proteins can't fit through the membrane.

Question 30

What is a tissue formed of and what does it do?

Answer 30

*Similar* cells (not all the same specialised cell), that work together to carry out a particular function.

Question 32

What do the guard cells do when the plant has little water?

Answer 32

The guard cells lose the water and become *falccid,* making the stomata close. This prevents too much water vapour escaping.

Question 33

Give 3 examples of tissues in mammals... what do they do? 1. M... 2. G... 3. E...

Answer 33

1. Muscular tissue... contract to move whatever it's attached to 2. Glandular tissue... makes and secretes chemicals, like enzymes and hormones 3. Epithelial tissue... covers some parts of the body e.g the inside of the gut

Question 34

4/5 in an animal cell - these are where most of the reactions for respiration take place. respiration releases energy that the cells need to work.

Answer 34

Mitochondria

Question 35

5/5 in an animal cell - these are where proteins are made in a cell

Answer 35

Ribosomes

Question 35

What are red blood cells adapted for?

Answer 35

They are adapted to carry oxygen, and are an important part of the blood.

Question 37

When does differentiation occur?

Answer 37

This occurs during the devlopment of the multicelluar organism.

Question 38

What 3 tissues is the stomach (organ) made up of?

Answer 38

1. Muscular ... to chrun up the food 2. Glandualr tissue ... makes digestive juices to digest food 3. Epithelial tissue ... covers the outside and inside of the stomach

Question 39

What is made up of organ systems?

Answer 39

Large multicellular organisms.

Question 40

2/5 in an animal cell - gell-like substance where most of the chemical reactions happen. It contains enzymes that control these chemical reactions.

Answer 40

Cytoplasm

Question 42

What is an organ systems, and what is it made of?

Answer 42

Organ systems are groups of organs working together to perform a particular function.

Question 43

What are guard cells adapted to do? What shape adaption does it have to do this?

Answer 43

Open and close pores. Special kidney shape which openes and closes the stomata (pores) in a leaf.