B11 - Hormonal Coordination

Question 1

What is a hormone?

Answer 1

• Chemical molecules released directly into blood
• Carried in blood to affect particular cells in particular organs (target organs)
• Control things in organs and cells that need constant adjustment.

Question 2

Give two differences between nervous and hormonal responses?

Answer 2

NERVES:
- Very fast action
- Act for a short time
- Act on a very precise area
HORMONES:
- Slower action
- Act for a long time
- Act in a more general way.

Question 3

Where is excess glucose stored in the body?

Answer 3

Stored as glycogen in liver and muscles

Question 4

What effect does the hormone glucagon have on blood glucose level?

Answer 4

*blood glucose too low*
=> Glucagon released
=> Liver turns glycogen into glucose
*glucose level restored*
(insulin is used when levels are too high)

Question 5

Describe two effects of FSH on the body

Answer 5

(produced in pituitary gland)

• Causes egg to mature in follicle in ovary
• Stimulates ovaries to produce oestrogen

Question 6

Which of the following is a hormonal contraceptive:

Condom; Plastic IUD; or Diaphragm?

Answer 6

• Plastic IUD - releases progesterone (Maintains uterus lining and inhibits release of LH and FSH)

Question 7

Briefly describe how IVF is carried out

Answer 7

*FSH and LH given before egg collection to stimulate several eggs to mature)
=> Egg cells collected from mother and fertlised in lab using father’s sperm
=> Fertilised eggs grown into embryos in lab
=> One or two embryos inserted into mother

Question 8

How does adrenaline prepare the body for ‘fight of flight’?

Answer 8

(Released in stressful situations)

Triggers mechanisms that increase supply of oxygen and glucose to cells in brain and muscles

Question 9

What is auxin

Answer 9

• Plant hormone that controls growth near the tips of shoots and roots.
• Controls growth of plant in response to light (phototropism) and gravity (gravitropism or geotropism).

Question 10

What is phototropism?

Answer 10

=> Shoot tip exposed to light accumulates more auxin on shaded side than lighted side.
=> Makes cells grow (elongate) faster on shaded side, so shoot bends towards light

Question 11

What is gravitropism?

Answer 11

for shoot growing sideways
=> Gravity provided unequal distribution of auxin (more on lower side)
=> Lower side grows faster, bending shoot upwards.

Question 12

Give three ways that auxin can be used commercially.

Answer 12

• Killing Weeds (disrupts normal growth patterns)
• Growing from Cuttings with Rooting Powder (produces clones)
• Growing Cells in Tissue Culture (produces clones)

Question 13

Which plant hormone is responsible for fruit ripening?

Answer 13

Ethene (controls cell division)

Question 14

What is the function of Gibberellin?

Answer 14

Stimulates:

• Seed Germination
• Stem Growth
• Flowering

Question 15

What is the difference between how Type 1 and Type 2 diabetes are usually controlled?

Answer 15

TYPE 1:
- Pancreas produces little or no insulin
- Treated with insulin injections throughout day
- Regular exercise and less foods rich in simple carbohydrates
TYPE 2:
- Resistant to own insulin
- No treatment
- Regular exercise and carbohydrate controlled diet