12 BIOLOGY MONTHLY TEST AUGUST

SECTION A

  1. Non-ambiguous
  2. Gorge Gamow . A sequence of 3 successive base specifies one amino acid in phenotype
  3. Homologous organ. Divergent evolution
  4. Opiate narcotic .suppresses the normal functioning of brain /relief from intense pain
  5. Refers to disease which starts destroying self cells due to genetic or unknown reason

SECTION B

  1. Histamines-chemicals causing inflammatory reactions

Interferon glycoprotein which protects non-infected cells from further viral infection

  1. (a)primary-bone marrow/thymus anyone

Secondary lymphoid organ-spleen/lymph nodes/MALT

(B)

primary / secondary
Site where immature lymphocytes differentiates / Sites where lymphocytes interact interact with antigens and proliferate as effectors cell
  1. (i)HWE equilibrium

+ +2pq=1

i.e is the sum total of all the allele frequency is 1 in a diploid means allele AA,means aa,2pq=aA

(ii)migration of selection of population to a new place , gene frequency change in original and new population .i.e new genes are added in a new population /lasts in old population .sometimes the change in allelic frequency so differentiates in new simple population and become different species . the original drifted population become founders and the effect is called founders effect.

  1. The amino acids are activated in the presence of ATP and linked to their cognate tRNA. This is called charging of tRNA.

When 2 charged tRNA’s are brought close formation of peptide bond between them occur energetically and the presence of a catalyst enhance the rate of peptide bond formation

CODON / ANTICODON
  1. Sequence of 3 nitrogenous bases on mRNA.
  2. Codes for particular a.a during translation
/
  1. sequence of 3 nitrogenous bases in tRNA
  2. complimentary to the codon on mRNA

REPETATIVE DNA / SATELLITE DNA
  1. Certain base sequence are repeated many times
/
  1. Large portion of gene is randomly repeated.

SECTION C

  1. (i)capping: addition of methyl guanocine triphosphate at 5’ end

(ii) Tailing: addition of 200 to 300 adenylate residue at the 3’ end

(iii) Splicing: removal of introns with the help of ‘snurps’ and rejoining of exons by ligase

To form processed and mature eukaruotiv mRNA ready for translation

Lac operon consists of –structural genes, promoter, repressor, lactose inducer

-lactose(inducer) inactivates the repressor and switch on the opern.

13. (a) A-Gametocytes of plasmodium onters the mosquito

(b)C- Fertilisation occurs in the intestine of mosquioto

(c) B- Salivary gland of female anopheles mosquito. This release sporozoids of mosquito.

14. Reason:- Social pressure, peer pressure, curiocity, experiment, depression, unsupportive family, frustration.

Avoid:- Undue peer pressure, educating and councelling of problems and stress to avoid disappointment and failures.

  1. a. DDT used for the first time –maximam mosquitoes died ,few survived due to variation .which showed resistance to DDT and reproduced successfully ,such mosquitoes population become DDT resistant due to natural selection .
  1. Natural selection –post industrialization –tree trunk covered by smoke ,dust ,coal, white winged moths are visible by predators and can be easily picked up,remained low in rural areas and due to white background white moth could not be detected thus reverse situation found

SECTION-D

  1. (i)Alleleic sequence variation and is inheritable mutation which is observed in a population at high frequency and is unique to each individual. A special type of polymorphism called VNTR( Variable Number Tandem Repeat) is composed of repeated copies of DNA sequence that lies adjacent to each other on the chromosome. Thus, polymorphism is the basis of DNA fingerprinting.

(ii) Methodology and Technique:-

(a)Amplification- many copies produced by PCR Technology.

(b)DNA is cut into small fragments with restriction endonuclease.

(c)Small DNA fragments are separated by gel electrophoresis.\

(d)Doublr stranded DNA separated to nsingle strand DNA by alkaline chemical.

(e)Southern Blotting- Transferring of DNA to nylon membrane sheet.

(f)Hybridisation- Binding of probes( known sequence) to specific nucleotide sequence that are complementary to them.

(g)Autoradiography-Hybridised DNA fragments are observed as dark bands on X-Ray.

  1. A-(i) AUG(Methionine) and is a start/initiator codon.

(ii) Chrosome 1 has most gene 2968 and Y chromosome has 231 genes.

(iii)As it had involved a lot of money, most advanced technology, numerous computers, many scientists and a long span of time.

B- Adaptive radiation is starting from a point and radiating to other areas of geography:-

Australian Marsupial each different from the other and evolved from the ancestral stock.

Placental mammal in Australia also exibhit adaptive radiation in evolving into varieties of such placental mammals, each of which appears similar to corresponding marsupial. Eg- Placental wolf and Tasmanian wolf(marsupial), lemur and spotted cuscus(marsupial).