B2 -- Responses to a changing enviroment

Question 1

What is homeostasis?

Answer 1

It is maintaining a stable internal environment.

Question 2

What happens when the body is too hot?

Answer 2

• Erector muscles relax, so hairs lay flat.
• lots of sweat produced, which evaporates and transfers heat to the surroundings.
• Vasodilation

Question 3

What happens when the body is too cold?

Answer 3

• Erector muscles contract, hairs stand on end to trap insulating layer of air.
• little sweat produced.
• Vasoconstriction.

Question 4

What happens when the blood glucose levels are too high?

Answer 4

When glucose levels get too high, a hormone called Insulin is produced by the pancreas. This gives a chemical message to the liver to store the glucose as glycogen. This decreases the amount of glucose levels and balances them.

Question 5

What happens when the blood glucose levels are too low?

Answer 5

When glucose levels get too low, a hormone called glucagon is produced by the pancreas. This gives a chemical message to the liver to release glycogen. This increases the amount of glucose levels and balances them.

Question 6

What is type 1 diabetes and how can it be controlled?

Answer 6

It is a lack of insulin.

Insulin therapy, healthy diet, regular exercise.

Question 7

What is type 2 diabetes and how can it be controlled?

Answer 7

It is a resistance to insulin.

Insulin therapy, healthy diet, regular exercise, and maybe weight loss if needed.

Question 8

Explain positive phototropism in shoots and its benefits.

include auxins and cell elongation.

Answer 8

When exposed to light, more auxin goes to the side in the shade. The cells elongate faster on the shaded side, so the shoot bend towards the light.

More light for photosynthesis–sugar–energy for growth

Question 9

How are plant hormones used in selective weed killers?

include the benefits of selective weed killers.

Answer 9

Weeds are broad-leaved and grasses/cereals are narrow-leaved.
Selective weed killers are used to disrupt the growth patterns of only broad-leaved plants which kills them and leaves the grasses and crops untouched.

Question 10

How are plant hormones used in rooting powder?

include the benefits of rooting powder.

Answer 10

If you stick a cutting in root powder, it won’t grow.
If you add rooting powder, containing a plant growth hormone, the cutting produces roots and grows as a new plant.
Rooting powder enables growers to produce clones of plants rapidly.