(i) The organisms exhibiting external fertilisation discharge a large number of gametes into the water to increase the chances of fertilisation.
(ii) In Marchantia, male and female reproductive organs are present on separate individuals. Such type of plants are called dioecious plants.

1. There is no relationship between the size and lifespan of an organism, e.g.
2.  the mango tree has a shorter lifespan as compared to a banyan tree though both are of same size.  (i) the size of crow and parrot is almost same but the life span is 15 yrs and 140 yrs, respectively.

In single-celled organisms like Amoeba and bacteria the parental body itself divides into two parts and becomes daughter cells. Each of these divided cells rapidly grows into adult organisms. Therefore, the parent cannot be said to have died, it continues living as daughter cells.

It leads to formation of fruit where ovules have been converted into seeds and ovary wall has formed fruit wall (pericarp). It is followed by dehiscence of fruits and seeds. Next step is dispersal of fruits and then germination of seeds occurs to form seedlings.

Cell differentiation is a must for formation of tissues and organs. In the absence of cell differentiation, the developing embryo will become a mass of similar cells. There would not be any plumule, radicle, cotyledons or embryo axis. A new plant will not be formed from such an embryo.

Vegetative reproduction is a type os asexual reproduction as
(i) A vegetative part of the plant functions as a propagule to produce new plant 
(ii) There is no gamete formation.
(iii) Vegetative reproduction, like asexual reproduction, is uniparental. The individuals formed are clones of the parent.

Due to self-incompatibility, self-pollination fails to take place. Due to self-incompatibility or self sterility, cross pollination is favoured.

(b), (e), (c), (f), (d) and (a)

1. In haploid organisms, meiosis occurs during development of zygote.
2. It is the only diploid stage (formed by the fusion of two haploid gametes) in the life-cycle that can undergo miosis.

(i) In mullticellular organisms, cells/ tissues are specialised for various functions; the function of reproduction is performed by one group of speciallised cells.
(ii) Not all cells of a multicellular organism retains the power of division at maturity; the cells which retain the power of division are localised and they alone can help in reproduction.