Seed : Definition MCQ - Practice Questions with Answers

The Seed

• After fertilization, the ovary develops into fruit and the ovules develop into seeds.
• A seed is made up of seed coat and an embryo. 

Structure of Dicotyledonous Seed:

• The outer and inner integuments of the ovule develop into the seed coat. 
• There are two cotyledons.
• Cotyledons are the embryonal leaves as they store food.
• The outer layer of the seed coat is called testa while the inner layer is called tegmen.
• The hilum is the scar on the seed coat through which the developing seeds were attached to the fruit.
• Within the seed coat, embryo is present.
• Embryo consists of an embryonal axis and cotyledons. 
• The radicle and plumule are present on the opposite end of the embryonal axis.
• Food storing tissue called the endosperm is also present. It is formed after triple fusion.
• It is generally absent in dicot seeds. So, these are called non-endospermic or non-albuminous seeds.
   

Structure of Monocotyledonous Seed

• These seeds have only a single cotyledon.
• These seeds contain a well-developed endosperm and are called albuminous or endospermic seeds.
• Orchids have non-endospermic monocot seeds.
• In cereals, the seed coat is membranous and fused with the fruit wall. Such fruits are called caryopsis or grains.
• In caryopsis, the endosperm is bulky and stores food.
• The aleurone layer is rich in proteins and separates the endosperm from embryo.
• The single cotyledon is called the scutellum.
• The plumule is covered with coleoptile.
• The radicle is covered with coleorhiza.