Homeostasis

Question 1

What is homeostasis?

Answer 1

The maintenance of a constant internal environment within the body.

Question 2

Why is homeostasis important?

Answer 2

Homeostasis is important because it is essential for the survival of cells, to be independent of surroundings and for metabolism to work efficiently.

Question 3

What are the 2 waste products that need to be removed and how they are produced and removed?

Answer 3

• CO2 - Produced by respiration, Removed via lungs.

- Urea - Produced by liver breaking down amino acids, Removed by kidneys + transferred to the bladder.

Question 4

A cell’s delicately balanced chemical reactions work best within narrow limits of…?

Answer 4

• Temp
• pH
• Solute concentration

Question 5

How is temperature Increased and decreased in the body?

Answer 5

• Increased by shivering

- Decreased by sweating

Question 6

How is ion content Increased and decreased in the body?

Answer 6

• Increased by eating

- Decreased by sweating / urine

Question 7

How is water content Increased and decreased in the body?

Answer 7

• Increased by drinking

- Decreased by sweating / urine

Question 8

How is blood glucose Increased and decreased in the body?

Answer 8

It’s increased and decreased by hormones.

Question 9

Most homeostatic mechanisms work by which type of feedback?

Answer 9

They work by negative feedback.

Question 10

What is negative feedback?

Answer 10

If something changes from the optimum it is corrected back.

Question 11

What do endotherms have?

Answer 11

They have a very constant body temperature.

Question 12

What are two endotherms?

Answer 12

• Mammals

- Birds

Question 13

What does this constant body temperature help with, in relation to their environment?

Answer 13

They can operate in low temperature environments, as they can keep their rate of enzyme activity high.

Question 14

What are two ectotherms?

Answer 14

• Fish
• Amphibians
• Reptiles

Question 15

How do ectotherms differ from endotherms?

Answer 15

Their temperature varies with the external temperature.

Question 16

What should be the core body temperature?

Answer 16

37 degrees

Question 17

What part of our body is mainly producing heat and from what?

Answer 17

The heat is mainly being produced from the liver during it’s metabolism.

Question 18

How does our skin control body temperature rising and falling?

Answer 18

• If our temperature rises, more blood flows close to the surface of the skin and glands release sweat.
• If our temperature drops, blood flows under the adipose tissue, we stop sweating, our hairs stand up and we shiver.

Question 19

Name three ways in which water is important to a living organism.

Answer 19

• *Metabolism
• *Medium for chemical reactions
• Movement of materials in and out of cells
• Transport system
• Lubricant
• Support
• *Temperature control
• Dispersal of reproductive cells and seeds

Question 20

How is water lost through our lungs?

Answer 20

Some water gets evaporated as we exhale from our warm lungs.

Question 21

How is water lost through our skin?

Answer 21

By evaporation from cells + through sweat.

Question 22

How is water lost through our intestines?

Answer 22

Water is lost through faeces.

Question 23

How is water lost through our kidneys?

Answer 23

n dissolving the poisons and wastes we wish to excrete from the body.

Question 24

What organs are in charge of regulating water intake mainly?

Answer 24

The kidneys

Question 25

What is the same given to the kidneys because they control the water in our body’s?

Answer 25

Osmoregulatory organs