Outcome 4 - Terrestrial Organisms

Question 1

Why is gas exchange internal?

Answer 1

To minimise evaporation.

Question 2

Why do structures have thin walls?

Answer 2

To increase the rate of gas exchange.

Question 3

Why do we have branching structures.

Answer 3

To increase the surface area available for gas exchange.

Question 4

Why do we have a dense network of blood vessels?

Answer 4

To collect and distribute diffused gas.

Question 5

What is diffusion?

Answer 5

Diffusion is the movement of a substance from an area of high concentration of that substance to low concentration of that substance.

Question 6

Give an example of diffusion during internal respiration.

Answer 6

During internal respiration, diffusion is the movement in the internal tissues between cells and capillaries.

Question 7

Give an example of diffusion during external respiration.

Answer 7

During external respiration, diffusion is when the gas is exchanged between the alveoli and the lung capillaries.

Question 8

What is the equation for the rate of diffusion?

Answer 8

rate of diffusion = amount of gas passing through and area/unit of time

Question 9

Give an example of diffusion.

Answer 9

Nutrients absorbed by the villi in the small intestine gets diffused into the blood which is constantly moving and the villi have a rich supply of, meaning diffusion is constantly happening because the blood with always have a lower concentration of nutrients than the small intestines.

Question 10

What happens when carbon dioxide builds up in the blood and its chemical equation.

Answer 10

The build up of carbon dioxide in the blood causes the production of carbonic acid- H2CO3.

Question 11

What are carbohydrates, proteins and lipids broken down into, respectively?

Answer 11

• Carbohydrates are broken down into glucose.
• Proteins are broken down into amino acids.
• Lipids (fats and oils) are broken down into fatty acids and glycerol.

Question 12

How does respiration occur in animals?

Answer 12

Air containing oxygen is breathed in
through the mouth/nose, passes the trachea, two bronchi, bronchiole tubes, bronchioles, and alveolar sacs which, finally, contain alveoli.

Question 13

What are the Nephrons?

Answer 13

Nephrons are filtering units which contain two important parts that sift through the blood. It is made up of two parts, the glomerulus which is a filter and the tubules. There is 1 million of these nephrons in each kidney.

Question 14

What are Tubules?

Answer 14

Tubules are tiny tubes which decided if the components sent to it by the glomerulus are needed in the body. If they are, it regulates the amounts which it sends back as needed by the body and determines what are waste products, like urea, and sends it to the bladder through ureters.

Question 15

What are Ureters?

Answer 15

Ureters are bilateral thin tubular structures that connect the kidney to the bladder. They create uterine as a waste product.

Question 16

What is the function of the kidneys?

Answer 16

Kidneys balance the amount of fluid in the body, detect waste in the blood such as urea (a leftover from the breakdown of protein) and know when to release vitamins, minerals and hormones needed for life. They sift through all of the body’s blood 20-25 times a day.

Question 17

What are kidneys made up of?

Answer 17

They are made up of a million filtering units called nephrons. Each nephron contains a filter called a glomerulus and a tubule. The glomerulus filters blood and tubules return needed substances to the blood and remove waste.