Question

define Three Types of stemthorn with examples briefly.​

Answer 1

Answer:

There are several types of stem cells that can be used for different purposes.

• Embryonic stem cells. Embryonic stem cells come from human embryos that are three to five days old. ...
• Non-embryonic (adult) stem cells. ...
• Induced pluripotent stem cells (iPSCs) ...
• Cord blood stem cells and amniotic fluid stem cells.

Answer 2

Explanation:

STEM MODIFICATION - DEFINITION

In some plants the stems are modified to perform the function of storage of food, support, protection and vegetative propagation.

For food storage: Rhizome (ginger), Tuber (potato), Bulb (onion), Corm (colocasia).

For support: Stem tendrils of watermelon, grapevine, cucumber.

For protection: Axillary buds of stem of citrus, Bougainvillea get modified into pointed thorns. They protect the plants from animals.

For vegetative propagation: Underground stems of grass, strawberry, lateral branches of mint and jasmine.

For assimilation of food: Flattened stem of Opuntia contains chlorophyll and performs photosynthesis.

MODIFICATION OF STEM - DEFINITION

The stem is the part of the plant that provides support and helps in conduction.

In some plants, the stem is modified for some other functions such as:

Underground stem modification- in such modification, stems remain under the soil and store the large amount of food e.g., potato, ginger etc.

Sub-aerial modification- in such modification, week stems lie horizontally on the ground and develop adventitious roots that help in vegetative propagation e.g., grass, pumpkin etc.

Aerial stem modification- in such modification, axillary buds are modified to thron and tendril for protection and support e.g., rose, pea etc.