3. Differentiate between the following pairs of terms : (a) Radicle and plumule. (b) Hilum and micropyle. (c) Testa and tegmen. 4. Give two functions of a fruit.
Answers
ANSWER:
a) Radicle and Plumule
The radicle is the first part that emerges from the seed during the germination through the micropyle (seed pore). It makes the roots of the new plant. Plumule emerges after the radicle and makes the stem of the new seedling. Cotyledons form the first leaves of the seedling.
b) Hilum and Micropyle
Hilum is a scar on a seed that shows the connection between the ovule and ovary while micropyle is a pore that shows the point from which the pollen tube entered the ovary during fertilization. So, this is the key difference between hilum and micropyle. Structurally, hilum is a larger area of a seed while micropyle is a small pore.
c) Testa and tegmen
The main difference between testa and tegmen is that testa is the outer seed coat whereas tegmen is the inner seed coat. Furthermore, testa is smooth, thick, impermeable, and may be colored while tegmen is a thin membranous and hyaline.
4.Fruit protects the seed.
Fruits also help in dispersal of seed by attracting insects.