Practical Activity

ROLE OF GROWTH & HORMONES IN PLANTS

ROLE OF GROWTH & HORMONES IN PLANTS.
Plant hormones are chemicals produced in very small amounts within the plant body, and play a very important part in regulating plant growth and development. Most growth hormones are produced at the tip of a shoot and transported downwards to the root. The root tip produces very small quantities of the hormones.
There are many different types of plant hormones and one well-known group is the auxins. Indoie acetic acid (IAA) is one best known auxin. Auxins are produced at the shoot and root tips.

TYPES OF GERMINATION

What are the types of germination?

The nature of germination varies in different seeds.
During germination the cotyledons may be brought above the soil surface.
This type of germination is called epigeal germination.
If during germination the cotyledons remain underground the type of germination is known as hypogeal.

CONDITIONS NECESSARY FOR GERMINATION

CONDITIONS NECESSARY FOR GERMINATION.

What are the conditions necessary for germination?

Seeds can easily be destroyed by unfavourable conditions such as excessive heat, cold or animals.
Seeds need certain conditions to germinate and grow.
Some of these conditions are external, for example water, oxygen and suitable temperature while others are internal such as enzymes, hormones and viability of the seeds themselves.