Make a list of plant and animal hormones
Answers
Answer:
Explanation:
Plant Hormones: Plant hormones control some aspects of the growth of plants such as cell division, cell enlargement and cell differentiation.
Phytohormones
Description
1. Auxins
Promote growth of plants.
They are secreted by the cells present at the tip of stems and roots.
Therefore, auxins control the phototropic and geotropic movements of plants.
Auxins accelerate growth of stems but reduce the growth in roots.
Synthetic auxins are used in horticulture.
2. Gibberellins
Promote cell differentiation in the presence of auxins.
They break seed dormancy.
They also break dormancy in buds.
Stimulate elongation of shoots.
3. Cytokinins
Promote cell division in plants.
Delay ageing of leaves.
Promote opening of stomata.
Promote fruit growth.
4. Abscisic Acid
Acts as a growth inhibitor.
It promotes dormancy in seeds and buds.
Promotes closing of stomata.
Promotes abscission, i.e. wilting and falling of leaves.
Detachment of flowers and fruits from the plants is due to abscisic acid.
Hormones in Animals: They are secreted by different endocrine glands.
Hormones
Functions
Disorders
1. Adrenaline
Produced by the adrenal glands.
Adrenaline prepares the body for the fight and flight mechanism.
When excited or in anger, the adrenal glands produce a lot of adrenaline.
It speeds up heart beat and breathing.
It raises the blood pressure.
Blood supply to the digestive system and skin is reduced, and the blood supply to the skeletal muscles is increased.
2. Thyroxine
Secreted by the thyroid gland.
Regulates carbohydrate, protein and fat metabolism.
It increases the basal metabolic rate (BMR).
It regulates body growth such as ossification of bones and mental development.
Simple goitre:
It is caused by iodine deficiency
Answer:
Plant hormones: auxin, abscisic acid, ethylene, gibberellins, cytokinins
Animal Hormones: Insulin,thyroxine, growth hormone