2i - Excretion

Question 1

Define excretion:

Answer 1

Excretion is the removal of metabolic waste from an organism

Question 2

Define metabolism

Answer 2

• all of the chemical reactions that occur in the cells of an organism

Question 3

What 2 very important metabolic reactions do plants carry out?

Answer 3

• photosynthesis- respiration

Question 4

During photosynthesis ______ ________ enters the leaf and ______ exits the leaf

Answer 4

• carbon dioxide- oxygen

Question 5

During respiration, ______ enters the leaf and ______ _______ exits the leaf

Answer 5

• oxygen- carbon dioxide

Question 6

What are the 6 substances excreted by animals?

Answer 6

• nitrogenous wastes
• carbon dioxide
• excess water
• excess salts
• bile salts and pigments
• soluble vitamins

Question 7

Why is feaces not excretion?

Answer 7

• just undigested food

- not a metabolic waste

Question 8

What does the kidney do for excretion?

Answer 8

• kidneys remove urea, water and ions from the blood

- kidney sends the wastes to your bladder to be excreted as urine

Question 9

What does the skin do in excretion?

Answer 9

• removes water and salt by sweating

Question 10

What does the lungs do in excretion?

Answer 10

• remove carbon dioxide and water from the blood when we breathe out

Question 11

Why does your body need to excrete these substances?

Answer 11

• metabolic waste products are toxic

- can cause sickness if left inside the body

Question 12

What is urea?

Answer 12

• excess protein can be toxic to the body
• amino acids from the protein are broken down in the liver
• they are turned into carbohydrates and urea

Question 13

What is urine?

Answer 13

• water (95%)
• salts
• nitrogenous wastes (urea)

Question 14

Which organ excretes your urine?

Answer 14

• urethra

Question 15

Cellular respiration in the ____________ produces a waste product : _______ _______

Answer 15

• mitochondria

- carbon dioxide