(i) The diagram is proinsulin as it contains C-peptide.
(ii) Mature insulin is synthesised by removal of extra stretch called C-peptide.

None of these - Plants are autotrophic and are called primary producers because they are self-sufficient to synthesise their own food. Also, there is nothing like secondary producers. 

A set of principles that may be used to regulate human activities in relation to the biological world are called bioethics.
These are important because the genetic modification of an organism can have unpredictable results when such organisms are introduced into the ecosystem.

The strategy of shedding of pollen before maturation of stigma is to prevent self-fertilisation and reduce inbreeding depression. Such mechanisms facilitate cross-pollination and produce genetically better yielding crops.

(i) The zygote will be XXY. It means the zygote is male with feminine characters.
(ii) This abnormality is called Klinefelter's syndrome.

The exine layer is made up of sporopollenin and intine is made up of cellulose and pectin material.
Exine layer protects the pollen from adverse environmental condition.

Littoral zone, limnetic zone and profundal zone.

Edaphic factore are related to soil and substratum, and include topography, background, minerals, pH, etc.

(c), (d), (b), (a).

India has high ecological diversity due to variety of topography, soil types, climates, rainfall zones, sea coasts.islands, etc. Ten well demarcated biogeographical zones with different biota occur in India.

'Stress' for plants refers to unfavourable environment condition that reduces growth and yield of plants. Plants encounter two types of stress.
(a) Drought, water-logging, snowing, high-temperature, salinity (Abiotic Stress Factors). Stomata get closed which leads to reduction in photosynthesis and plant yield.
(b) Animals and Man (Biotic Stress).

Yes. Dedifferentiation is key to development of cell division and growth of plant mass callus. Callus can be subdivided at regular intervals and the subcultures allowed differentiate and form plantlets.

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.

Among the common STDs, hepatitis-B and AIDS are not infections of the reproductive organs though their mode
of transmission could be through sexual contact also.All other diseases like gonorrhoea, syphilis, genital herpes, hepatitis-B are transmitted through sexual contact and are also infections of the reproductíive tract,so these are STDs as well as RTIs, whereas, AIDS and hepatitis, STDs, but not RTIs.

(i) User-friendly, i.e., comfortable and easy to use.
(ii) Without any side effect.
(iii) Reversible.
(iv) Completely effective against pregnancy.

Self-pollination and cross-pollination both can occur in chasmogamous flower. For details,refer Basics and Basis.

In a 3-celled pollen, there is one vegetative or tube cell and two male gametes. in two-celled pollen, there is one vegetative cell and a generative cell. Here  the generative cell divides in the pollen tube to form two male gametes which are already present in 3-celled pollen. Therefore, there is no need for further division in 3-celled pollen. 

Primary endosperm cell (PEC) is to form the food laden endosperm for nourishment of developing embryo. Therefore, division of PEC for production of endosperm is a pre-requisite for division of zygote in the formation of embryo.

Vivipary is nourishment and growth of embryo inside the body of the female till it becomes fully formed and delivered. Vivipary provides protection and assured nourishment to the young ones. As the female has a limited space and nourishment, the number of youngones always kept low, e.g., one in humans and cattle, 6-12 in Rabbit and Rat.

1. The microbes are also heterotrophs.
2. Those microbes which meet their energy requirement by degrading the dead and decaying organic matter,are called decomposers.
3. Those microbes which depend on living organisms for their food as well as shelter, are called parasites.

1. The rate of decomposition is regulated by temperature and soil moisture, as they influence the activities of decomposers.
2. The trophic have a warm/hot and humid condition; such a condition is favourable for the decomposers and hence they speed up the process of decomposition.

(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.

No, there is no relationship between the size of an organisms and its lifespan, e.g.
1. The size of crows and parrots is almost same, but the lifespan of crows is 15 years while that of parrots is 140 years.
2. A mango tree has a much shorter lifespan, compared to a peepal tree, though they both are of similar size.