stuctures and functions in living organisms (topic 2)

Question 1

when its hot…

Answer 1

• sweat is produced from sweat glands
• vasodilation means more blood flows closer to the surface of the skin, resulting in increased energy transfer from the body

Question 2

human body temperature

Answer 2

37 degrees celsius

Question 3

the thermoregulatory centre

Answer 3

monitors and controls body temperature to ensure it remains 37 degrees celsius is found in the brain.
has receptors that monitor the temperature of the blood, has receptors in the skin that send impulses to the thermoregulatory centre.

Question 4

when its cold…

Answer 4

• sweating stops
• skeletal muscles contract rapitdly (shivering) to generate heat from respiration
• hairs stand on end to create an insulating layer, trapping warm air
• vasconstriction means blood doesnt flow so close to the surface, resulting in less heat loss

Question 5

osmosis

Answer 5

the movement of water from a less concentrated solution to a more concentrated one through a semi permeable membrane.

Question 6

Stem cell

Answer 6

undifferentiated cell of an organism that is capable of dividing an unlimited number of times.

Question 7

Specialised cells

Answer 7

have developed certain characteristics allowing them to perform specific functions. The differences are controlled by genes in the nucleus.

Question 8

Cell differentiation

Answer 8

process by which the cell changes to become specialised.