Maharashtra Board HSC Science Question Paper

[Nitin Sharma]

Any buddy, please provide me the Maharashtra Board HSC Science Question Paper…………

As per your request here I am sharing the Maharashtra Board HSC Science Question Paper:

i. The pattern of ecosystem in which density and distribution of species vary along a horizontal gradient
is _______.
(A) zonation
(B) stratification
(C) ecological niche
(D) speciation
ii. The enzyme affecting the shelf life of flavr savr tomato is _______.
(A) galactosidase
(B) trans acetylase
(C) permease
(D) polygalactouranase
iii. In nomenclature of RENs (restriction endo-nucleases) Hind III, III stands for ______.
(A) genus name
(B) species name
(C) order of discovery
(D) strain of the organism
iv. Rhizobium phaseoli fixes atmospheric nitrogen symbiotically in _______.
(A) pea (B) bean
(C) jowar (D) maize
v. In nucleotide, the nitrogen base is attached to carbon no.1 of sugar by _______ bond.
(A) glycosidic (B) hydrogen
(C) phosphodiester (D) phosphate
vi. During biogas production microorganism used to bring about the anaerobic digestion is _______.
(A) Pseudomonas (B) Rhizopus
(C) Methanococcus (D) Methanobacillus
vii. A wheat variety resistant to hill bunt disease is ________.
(A) Pusa Shubhra (B) Himgiri
(C) Pusa Gaurav (D) Pusa Sawani
Std. XII Sci.: Perfect Biology - I

Q.2. (A) Answer in One sentence each: (6) [12]
1. Define the term ‘leaching’.
2. Give reason –
‘Buttermilk is used in the dough of dhokla.’
3. What is palindrome in DNA?
4. What is biomagnification?
5. Give application of mutation breeding.
6. What will be the length of eukaryotic DNA segment having 10 pairs of nucleotides?
(B) Draw a neat labelled diagram of the hair pin model of t-RNA. (2)
(C) Attempt Any TWO of the following: (4)
1. Give schematic representation of carbon cycle.
2. What is respiratory quotient (RQ)? Why RQ in anaerobic respiration is infinite?
3. Explain the structure of male gametophyte of angiosperms with the help of a suitable diagram.
4. Explain how suspension culture is prepared from callus.

Q.3. (A) Attempt any TWO of the following: (6) [9]
1. What are biocontrol agents? Mention any two groups of biocontrol agents and their hosts.

2. ‘In incomplete dominance and co-dominance, genotypic and phenotypic ratios are identical.’
Explain how co-dominance differs from incomplete dominance in phenotypic nature of their
hybrids.

3. Describe characteristics of genetic code.
(B) Draw a neat labelled diagram showing steps of PCR. (3)
Q.4. Describe the ultrastructure of chloroplast. Add a note on the significance of photosynthesis. [7]
OR
Define geitonogamy and xenogamy. Give advantages of self pollination and cross pollination.
Explain how dichogamy favours cross pollination.