The Need for Transport

Question 0

WHat happens to the water that passes through plants?

Answer 0

1% is used for photosynthesis and turgor.

99% evaporates from the leaves.

Question 1

Why do plants need water?

Answer 1

It is a raw material for photosynthesis, providing the hydrogen to convert carbon dioxide gas to sugar. It transports sugar and minerals around the plant. It is also required for the maintenance of turgor in cells giving the plant support. It helps cool plants when it evaporates from leaves.

Question 2

What carries water and minerals?

Answer 2

Tubes in the stem called xylem vessels.

Question 3

What else do xylem vessels do?

Answer 3

They strengthen the stems of woody plants by laying down a special substance called lignin.

Question 4

What carries food around the plant?

Answer 4

Tubes called phloem carry food from the leaves to every part of the plant.

Question 5

What feature of leaves allow the exchange of carbon dioxide ot oxygen?

Answer 5

The stomata (sing. stoma)

Question 6

Name some features of the upper epidermis.

Answer 6

The cuticle, the cell wall, the nucleus, the cytoplasm.

Question 7

Name some features of the palisade mesophyll.

Answer 7

The vacuole and chloroplasts.

Question 8

Where are guard cells found?

Answer 8

In the lower epidermis.

Question 9

What is transpiration?

Answer 9

The process in which water evaporates from the surface of a leaf through microscopic pores (stomata).

Question 10

What does the loss of water lead to?

Answer 10

The creation of a suction force that pulls up more water from the roots.

Question 11

What is the circulatory system?

Answer 11

The system that transports blood to all parts of the body. It consists of the heart and a vast network of blood vessels.

Question 12

What are some things the blood does?

Answer 12

It carries food and oxygen to all cells and removes carbon dioxide and waste materials.

Question 13

What is the heart?

Answer 13

A muscle that pumps blood through the blood vessels to all aprts of the body.

Question 14

What are the outside walls of the heart made out of?

Answer 14

Cardiac muscle.

Question 15

What does the heart need?

Answer 15

Its own supply of blood to receive food and oxygen. It is the coronary arteries that supply the heart with this.

Question 16

How many chamber does the heart have?

Answer 16

4. The two upper chambers are called atria. The two lowet chambers are called ventricles.

Question 17

What do the left side and right side of the heart do?

Answer 17

The left side pumps blood from the lungs around the body and the right side pumps blood received from the body to the lungs.

Question 18

What is a valve?

Answer 18

A valve is a device that allows fluids to pass through it in one direction only. The heart has 4 valves.

Question 19

Incoming blood arrives in each …

It then passes through a valve to the corresponding …

Answer 19

atrium

ventricle

Question 20

How many times does blood pass through the heart in each circulation?

Answer 20

Twice.

Question 21

Describe arteries.

Answer 21

They take blood out away from the heart.
They have thick walls.
They carry oxygenated blood.
They bulge as blood forces through them, causing a pulse.

Question 22

Describe capillaries.

Answer 22

Their walls are only one cell thick.

They allows the exchange of material with cells.

Question 23

Describe veins.

Answer 23

They take blood to the heart.
They have thin walls and valves to stop the backflow of blood.
They carry deoxygenated blood.

Question 24

How is oxyhaemoglobin made?

Answer 24

Oxygen diffuses through the walls of the sacs into the blood capillaries. It is taken up by red blood cells and combines with haemoglobin.

Question 25

What is oxygenated blood?

Answer 25

Bright red blood containing lots of oxygen.

Question 26

What happens when we breathe?

Answer 26

The air first passes down the trachea then splits into two tubes called bronchi, one leading to each lung. Each bronchus then splits into smaller branches called bronchioles. These end in tiny air sacs called alveoli. Gas exchange takes place here. Oxygen enters the blood and carbon dioxide enters the air sacs to be breathed out.

Question 27

Why are alveoli effective at their job?

Answer 27

- The surface of each alveoli is moist which allows oxygen to dissolve before diffusion. - The lining of each alveolus is very thin which allows oxygen to pass through very easily. - The alveoli are surrounded by a large network of capillaries for greater absorption of oxygen.

Question 28

How do lungs keep themselves clean?

Answer 28

Sticky mucus is produced by goblet cells in the air passages that trap dust and germs that enter the lungs. The air passages are lined with tiny hairs called ciloi that sweep the mucus up to the back of the throat.

Question 29

What is peristalsis?

Answer 29

The muscular transport of food through the digestive system.

Question 30

How does peristalsis work?

Answer 30

Longitudinal muscles and circular muscles in the alimentary canal work together in a squeezing motion that pushes food along. The muscles behind the food contract. The muscles in front of the food relax.

Question 31

What are villi?

Answer 31

Tiny 'fingers' which line the small intestine.

Question 32

What features do villi have?

Answer 32

- Thin cell lining only one cell thick, easy for nutrients to pass through. - Excellent blood supply, sugars and amino acids diffuse into their blood capillaries. - Lacteal absorbs digested fats which are passes into the lymphatic system.