13.
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.
Radicle: In a seed the radicle lies downwards near the lower pointed end of the grain. It gives rise to the root.
b.) 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.
c.) Testa is the outer covering of the seed whereas tegmen is the covering which lies under the testa.
Testa provides protection from bacteria and natural sources whereas tegmen directly cover the seed and gives protection
4.)The functions of the fruit is to protect the seed inside and aid in its dispersal. Some fruits harden to make accessing the seed difficult. Many fruits promote wind dispersal.
Answer:
A) 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.
B) The hilum is a scar on the seed coat marking where the seed was attached whereas micropyle is the pore in the seed coat. ... The hilum is the point which attaches ovule to the placenta whereas water is absorbed through micropyle into the embryo of seed during germination.
C) 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. Testa and tegmen are the two seed coats found in the bitegmic seed of dicots.
D) The functions of the fruit is to protect the seed inside and aid in its dispersal. Some fruits harden to make accessing the seed difficult. Many fruits promote wind dispersal .