Organisms and Populations — BIOLOGY STD 12 Science — Question

How many ova will be produced by one fully grown primary oocyte?

In a dihybrid cross white eyed, yellow bodied female Drosophila crossed with red eyed, brown bodied male Drosophila produced in F₂ generation, 1.3 per cent recombinants and 98.7 per cent progeny with parental type combinations. This observation of Morgan deviated from Mendelian F₂ phenotypic dihybrid ratio. Explain, giving reasons, Morgan’s observations.

Write the use of the following in biotechnology.
Plasmid.

Differentiate between Down's syndrome and Turner's syndrome.

Explain how did von Helmont supported the theory of spontaneous generation?

Retrovirus do not follow central dogma. Comment.

Describe the structure of megasporangium.

Answer the following questions:
List the differences between the embryos of dicot (pea) and monocot (grass family).

Explain the contribution of Thermus aquaticus in the amplification of a gene of interest.

(i) It was estimated that if an evergreen forest has a GPP of 400 J/m²/day and 150 J/m²/day worth of carbon dioxide flows out of that forest, what is the NPP in that forest?
(ii) Explain why pyramids of energy must always be upright.