Evolution — BIOLOGY STD 12 Science — Question

Mention four significant services that a healthy forest ecosystem provide.

Koel is clever enough to lay eggs in Crow's nest. Write the reason for this peculiar behaviour. Name the type of interaction.

Desribe characteristics of seed.

Group the following as nitrogenous bases and nucleosides:
Adenine, Cytidine, Thymine, Guanosine, Uracil and Cytosine.

Certain attributes of innate immunity are given in the table below. Identify A, B, C, D, E and Frespectively in it.

S.No.	Type of barrier	Example of the barrier	Function
(і)	А	B	Prevent microbial growth
(ii)	C	Polymorpho nuclear leucocytes	D
(iii)	Cytokine	E	F

Identify the following pairs as Homologous or Analogous organs:

1. Sweet potato and potato
2. Eye of octopus and eye of mammals
3. Thorns of Bougainvillea and tendrils of Cucurbits.
4. Fore limbs of Bat and Whale.

If the Tropical rainforest would have been from the present 6% areas of earth to 12% areas how would the biodiversity be affected by it? Explain with reason.

If a patient is advised Anti Retroviral Therapy, which infection is he suffering from? Name the causative organism.

There is only one possible sequence of amino acids when deduced from a given nucleotides. But multiple nucleotides sequence can be deduced from a single amino acid sequence. Explain this phenomena

Differentiate beween National Parks and Sanctuaries.