Question

Give scientific reasons.(Any Two)

1. Peripatus is said to be the connecting link between annelida and arthropoda.
2. Fertilization in plants is called double fertilization.
3. Nowadays school children have to deal with mental stress.

Answer 1

Peripatus is said to be the connecting link between annelida and arthropoda because it shows the morphological characteristics of both the groups. Peripatus possesses the characteristics like segmented body, thin cuticle, and parapodia like organs similar to annelids. These also show tracheal respiration and open circulatory system similar to arthropods.

In plants, as the pollen grain falls upon the sticky stigma, the long pollen tube formed carries the two male gamete along the style into the embryo sac. Inside the embryo sac one of the male gamete fuses with the egg cell to form the zygote and the second male gamete fuses with the two polar nuclei to form the endosperm. Since, there are two fertilisations involved, it is called double fertilisation.

Nowadays school children have to deal with mental stress due to increased competition in the educational field. Children are also facing loneliness because of nuclear families and parents staying outdoors for their jobs. Girls are also victims of mental stress due to the genderinequality in their family, school, and the society.Girls also have to sometimes unnecessarily have to face the problems like teasing and molesting. Children tend to have mental stress due to higher expectations of parents as well.