Short Answer Type(a) Organisms may be conformers or regulators. Explain this statement and give one example of each.
(b) Why are there more conformers than regulators in the animal world ?
Describe the inter-relationship between productivity, gross primary productivity and net productivity.
Long Answer TypeIt is commonly observed that parents feel embarrassed to discuss freely with their adolescent children about sexuality and reproduction. The result of this parental inhibition is that the children go astray sometimes.
(a) Explain the reasons that you feel are behind such embarrassment amongst some parents to freely discuss such issues with their growing children.
(b) By taking one example of a local plant and animal, how would you help these parents to overcome such inhibitions about reproduction and sexuality ?
(a) When a seed of an orange is squeezed, many embryos, instead of one are observed. Explain how it is possible.
(b) Are these embryos genetically similar or different ? Comment.
(a) It is due to polyembryony. Occurrence of more than one embryos in a seed is called as POLYEMBRYONY. In orange, the nucellar cells, synergid or integument cells develops into a number of embryos of different sizes. eg : - Citrus.
* Sometimes formation of more than one egg in an embryo sac can lead to polyembryony.
(b) In such embryos parental characters are maintained hence they are genetically similar. In this process, there is no segregation of characters in the offspring (progeny).
(a) Compare, giving reasons, the J-shaped and S-shaped models of population growth of a species.
(b) Explain ‘fitness of a species’’ as mentioned by Darwin.
Write the different components of a lac-operon in E. coli. Explain its expression while in an ’open’ state.
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