B2

Question 1

What are the difference between cardiac muscles and other muscles?

Answer 1

Cardiac muscles do not receive electric impulses to contract

Question 2

Why is the wall of the right ventricle thinnner than the wall of the left ventricle?

Answer 2

Because the right ventricle only has to pump blood to the lungs whereas the left ventricle has to pump blood to the whole body

Question 3

What is in blood?

Answer 3

Red blood cells, white blood cells, plasma , Platelets

Question 4

What are Platelets?

Answer 4

Platelets are tiny structures that help blood to clot

Question 5

What are white blood cells and how are they adapted to do their job?

Answer 5

White blood cells are large cells that contain a nucleus. They fight diseases by making antibodies and can change shape to engulf microorganisms.

Question 6

What are red blood cells and ho are they adapted to do their job?

Answer 6

Red blood cells are small biconcave elks that carry oxygen. They are biconcave and have no nucleus to increase their surface area (so that they can carry ore oxygen) and contain haemoglobin (a substance that binds to oxygen)

Question 7

What is plasma and how is it adapted to do its job?

Answer 7

Plasma is the liquid that blood cells float in. It is 90% water and many materials are transported by being dissolved in plasma

Question 8

Which type of cell is most common in blood?

Answer 8

Red blood cells

Question 9

What are the three blood vessels?

Answer 9

Arteries, veins and capillaries

Question 10

Is the pressure high or low in an artery?

Answer 10

High

Question 11

Is the pressure high or low in a vein?

Answer 11

Low

Question 12

Is the pressure high or low in a capillary?

Answer 12

Low

Question 13

How are arteries adapted to withstand high pressures?

Answer 13

They have a thick outer wall and a thick layer of muscle and elastic fibres

Question 14

How are veins adapted to carry a large amount of oxygenated blood?

Answer 14

They have large lumens

Question 15

How are capillaries adapted to transport oxygen and other substances to tissues and organs?

Answer 15

They have semipermeable walls that are one cell thick to allow oxygen and other substances to diffuse through them to get to the tissues and organs

Question 16

Why do veins have valves?

Answer 16

To prevent back flow

Question 17

Which side is the bicuspid valve on?

Answer 17

The left side

Question 18

Which side is the tricuspid valve on?

Answer 18

The right side

Question 19

What two structures does a plant transport materials through?

Answer 19

The xylem and the phloem

Question 20

What is the structure of the xylem?

Answer 20

It is made from dead cells that are stiffened with lignin

Question 21

What is the structure of the phloem?

Answer 21

It is made from living cells

The cell walls of these cells form sieves which allow dissolved sugars to pass through

Question 22

How do vascular bundles provide support?

Answer 22

They form a network in leaves that supports the softer leaf tissue
They are located around the outside if the stem to provide strength and resistance to the wind
They are found in the centre which strengthens the root and makes it act like an anchor

Question 23

What is transpiration?

Answer 23

Transpiration is the loss of water from a plants leaves

Question 24

What is the transpiration stream?

Answer 24

The constant flow of water from the roots through the xylem and out of the leaves

Question 25

How does water enter the xylem?

Answer 25

Water diffuses from the soil into the root hairs by osmosis It then travels form cell to cell until it reaches the centre of the root. Once inside the xylem, the water can be transported through the plant

Question 26

How is water lost from leaves?

Answer 26

Through the stomata

Question 27

Why does the stomata open?

Answer 27

When there is plenty if light and water, the guard cells take up water by osmosis This makes then swell and becom turgid, opening the stomata

Question 28

Why does the stomata close?

Answer 28

When the conditions for photosynthesis are not good, guard cells lose water. They become floppy and the stomata close

Question 29

Why do plants wilt?

Answer 29

Because a plant loses water faster than it takes it in

Question 30

What equation can be used for maeasuring the rate of transpiration?

Answer 30

Rate of movement = distance/time

Question 31

What equipment can you use to measure how quickly a plant takes up water?

Answer 31

A potometer

Question 32

How do you use a potometer to measure transpiration?

Answer 32

1. Take an air bubble into the capillary tube 2. As water moves into the shoot and evaporates from its leaves the air bubble will move towards the plant. 3. Measure how fast the air bubble travels. This will give an indication of how fast the plant is transpiring 4. Refill the capillary tube and repeat the measurements.

Question 33

What is diffusion?

Answer 33

The movement of particles from a higher concentration to a lower concentration. They move down the concentration gradient

Question 34

Is energy transferred in diffusion?

Answer 34

No. It is a passive process

Question 35

How does the distance that the particles need to move over affect the rate of diffusion?

Answer 35

The lower the distance, the higher the rate of diffusion. This is because it takes less time to travel a shorter distance

Question 36

How does the concentration gradient affect the rate of diffusion?

Answer 36

The steeper the concentration gradient, the highe the rate of diffusion. This is because there is a greater net movement of the particles

Question 37

How does surface area affect the rate of diffusion?

Answer 37

The higher the surface area, the higher the rate of diffusion. This is because there is more space for diffusion so more particles can move in a period of time

Question 38

How do you calculate percentage change?

Answer 38

New result - original result/Orginal result

Question 39

What is osmosis?

Answer 39

Osmosis is the diffusion if water across a semi permeable membrane

Question 40

What is lysis in blood cells?

Answer 40

When a cell bursts

Question 41

What does the term ‘the cell becomes crenated mean’?

Answer 41

The cell crinkles due to a loss of water

Question 42

What does the term ‘turgid’ mean?

Answer 42

When the cell is full of water and has a higher pressure

Question 43

What does the term ‘flaccid’ mean?

Answer 43

When the pressure in the cell falls and the cell becomes soft

Question 44

What does the term ‘plasmolysed’ mean?

Answer 44

When the cell contents collapse form the cell wall

Question 45

What happens when there is a higher water potential outside the plant cell? (When the surroundings are less concentrated)?

Answer 45

The cell takes up water by osmosis and becomes turgid

Question 46

What happens when the plant cell has the same concentration as the surroundings

Answer 46

Water just passes through the cell

Question 47

What happens when the surroundings have a lower water potential than the plant cell?

Answer 47

The plant cell becomes flaccid and then plasmolysed

Question 48

What happens when there is a higher water potential outside the animal cell? (When the surroundings are less concentrated)?

Answer 48

The cell takes up a lot of water and may burst

Question 49

What happens when the animal cell has the same concentration as the surroundings

Answer 49

Water just passes through the cell

Question 50

What happens when the surroundings have a lower water potential than the plant cell?

Answer 50

The cell loses water by osmosis and becomes crenated

Question 51

What is active transport?

Answer 51

Active transport allows the cells substances to move from an area of low concentration to an area of high concentration. The particles are moving up or against the concentration gradient

Question 52

What type of energy is required in active transport?

Answer 52

ATP energy

Question 53

What are carrier proteins?

Answer 53

Carrier proteins are proteins that are across the width of the cell membrane and transport molecules of substances into the cell. The useful molecule will bind to the carrier protein. The the carrier protein will rotate and deliver the useful molecule into the cell

Question 54

Where are stem cells found in animals?

Answer 54

Embryos (embryonic stem cells) | Adults (bone marrow, skin, liver)

Question 55

Where are stems cells found in plants?

Answer 55

In the meristems | The meristems are found at the tips of the roots and shoots and around the stem