Excretion

Question 1

Excretion

Answer 1

The removal of metabolic waste from the body

Question 2

Homeostasis

Answer 2

The maintenance of a constant internal environment in an organism

Question 3

Ectotherms

Answer 3

Gain or lose heat from or to their external environment

Eg. Frogs, snakes , fish

Question 4

Endotherms

Answer 4

Generate their own heat from metabolic reactions.

Eg . Humans , dogs

Question 5

Role of excretory system in homeostasis

Answer 5

• regulating body temp
• controls osmosis
• controls concentration of body fluids
• removes waste products of body

Question 6

Organs of excretion

Answer 6

Lungs - water + CO2
Skin - water + salts
Kidneys - water, salts , urea

Question 7

Urinary system

Answer 7

2 kidneys , 2 ureters, the bladder and the urethra

Question 8

Functions of the kidney

Answer 8

• excretion
• osmoregulation
• pH control

Question 9

Filtration in kidney

Answer 9

Incoming blood is filtered in the outer cortex

Question 10

Reabsorption in kidney

Answer 10

Useful materials are then taken back into the blood in the cortex and medulla

Question 11

Secretion in kidney

Answer 11

Substances are secretes from blood into the cortex

Question 12

Nephrons

Answer 12

Carry out functions of kidneys.

Located in cortex and medulla of the kidney

Question 13

Where does filtration take place?

Answer 13

Glomerulus

Question 14

Ultra-filtration

Answer 14

Filtration in the Bowman Capsule as there is high pressure

Question 15

Epidermis

Answer 15

Outer layer of skin

Question 16

Melanin

Answer 16

Specialised cells created in malphigian layer. Protects skin against UV radiation

Question 17

Malphigian layer

Answer 17

Pigments skin, hair and colour of eyes

Question 18

Dermis

Answer 18

Inner layer of skin , contains strong protein called collagen

Question 19

Subcutaneous layer

Answer 19

Contains fat in adipose tissues

Question 20

Functions of the skin

Answer 20

Protection 
Vitamin production - D
Food store - fat 
Sense organ 
Excretion - sweat 
Temperature regulation

Question 21

ADH

Answer 21

Anti diuretic hormone.

Volume of urine produced is controlled by this hormone

Question 22

Where is ADH produced

Answer 22

Hypothalamus

Stored + released from pituitary gland