Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

Describe sex-determination in birds with example.

Identify by giving reasons, the salient features of genetic code by studying the following nucleotide sequence of mRNA strand and the polypeptide translated from it.
(AUG UUU UCU UUU UUU UCU UAG) (Met - Phe - Ser - Phe - Phe - Ser)

Name the kind of organisms which constitute the pioneer community of xerarch and hydrarch successions respectively.

Given below is a list of six micro-organisms. State their usefulness to humans.

1. Nucleopolyhedrovirus.
2. Saccharomyces cerevisiae.
3. Monascus purpureus.
4. Trichoderma polysporum.
5. Penicillium notatum.
6. Propionibacterium sharmanii.

How are eurythermal animals different from stenothermal animals? Give an example of each.

Mendel crossed plants that breed true for yellow seeds with plants that breed true for green seeds. All seeds in F-generation were yellow. Work out the inheritance involved in this cross by using symbols for each traits and state which trait was dominant?

How tobacco plant is made pest resistance from nematodes?###Explain RNA interference with example.###Explain: Pest resistance Plants.

1. Match the microbes listed under Column-A with the products mentioned under Column-B.

	Column-A		Column-B
(a)	Penicillium notatum	(i)	Statin
(b)	Trichoderma polysporum	(ii)	Ethanol
(c)	Monascus purpurea	(iii)	Antibiotic
(d)	Saccharomyces cerevisiae	(iv)	Cyclosporin-A

2. Why does ‘Swiss Cheese’ develop large holes?

What is artificial hybridisation? How it can be achieved?

Explain the process of fertilization by defining the insemination.