Seeds - Structure and Germination

Hilum

Hilum

________ is a distinct whitish oval sear on the concave side of the seed.

Dicotyledonous seeds

________ contain two cotyledons.

suitable temperature

Water, ________, and air (oxygen) are necessary for germination.

upper broader side

The plumule is towards the ________ of the embryonic region and is enclosed in a protective sheath, the coleoptile.

diffusion of respiratory

It provides for the ________ gases for the growing embryo.

embryo

The ________ consists of a single cotyledon here called scutellum, a radicle, and a plumule.

radicle

The ________ emerges, grows downwards, and forms the root system.

Oxygen

________: During germination, there is rapid cell division and cell growth for which energy is required.

Grain

________ as found in maize, wheat, etc, is actually the fruit in which the fruit wall and the seed coat are fused together to form a protective layer.

epicotyl

If the ________ elongates, the cotyledons remain underground (or on the ground if the seed is just on the ground) and the germination is then called hypogeal.

tube

It marks the opening through which the pollen ________ entered the ovule.

Fruit

________ is the enlarged ripened version of the ovarian wall forming the cell wall enclosing the seed.

plumule

The ________ grows upwards and forms the shoot of the seedling.

Germination

________ is the process of formation of seedlings developed from the embryo.

thin epithelial layer

The endosperm and the embryonic part are separated from each other by a(n) ________.

diffusable form

Water is necessary for chemical reactions and for the enzymes to act upon the food stored in the cotyledons or endosperm so that it may convert into a(n) ________ dissolved and utilized by the growing embryo.

fresh seed

A(n) ________ from a plant normally does not germinate even if the conditions for germination are favorable.

delicate inner parts

It protects the ________ of the seed from injury and from the attack of bacteria, fungi, and insects tegmen is a thin inner layer lying next to the testa, and this also is protective.

maize grain

The ________ is actually a one- seeded fruit in which the fruit wall and the seed coat are fused together to form a protective layer.

Albuminous

________ (endospermic) cotyledons are thin and membranous and endosperm persists.

albuminous seeds

Monocot ________: cereals, millets, palm.

Exalbuminous

________ (non- endospermic)- In such seeds, the cotyledon stores food and becomes thick and fleshy.

Monocotyledonous seeds

________ contain one cotyledon (seed leaf)

fruit

The ________ protects the seed and helps in dispersal.

epicotyl

Both the ________ and hypocotyl of the seed never elongate together during germination.

epicotyl

It is either the ________ or the hypocotyl that elongates.

Example

maize, grasses

Examples

peas, gram, and beans

Examples

poppy seeds, and orchid seeds

Monocot albuminous seeds

cereals, millets, palm

Exalbuminous (non-endospermic)

In such seeds, the cotyledon stores food and becomes thick and fleshy

Water

The seed obtains water from its environment, i.e

The seed swells and consequently the seed

coat ruptures allowing the elongating radicle to come out and form the root system

Suitable Temperatures

Both very low and very high temperatures are unsuitable for germination

Oxygen

During germination, there is rapid cell division and cell growth for which energy is required

The experiment set-up is left in a warm place for a few days result is as follows

Examples

peas and gram

Examples

castor, bean, etc