PRELIM EXAMINATION I
CLASS XII BIOLOGY
MAX. MARKS: 70 TIME: 3 HRS
NAME____________ CLASS_____SECTION__________ ROLL NO.
This paper comprises of two Parts- I and II. Answer all Questions
PART I (20 Marks)
Q.1 (a) Answer the following as per instructions (Attempt all questions) : [8x1]
i)If a segment of double-stranded DNA has 18% thymine, calculate the
percentage of cytosine in the DNA.
ii)A woman has normal vision, but her father is colour-blind. If she marries
a colour-blind man, what is the probability of her son being colour-blind?
iii)What are Ramsar sites?
iv)Name the bond which exists between chain-A and chain-B of human
insulin.
v)Name the toxin responsible for causing the symptoms of malaria.
vi)Give the biological name of the causative agent of Syphilis.
vii)What are Analogous organs? Give ONE example from Plant Kingdom.
viii)What is the function of prostaglandins present in the secretion of
vesicle?
b)State the best known contributions of the following: [4x1]
i) Ernst Haeckel ii) Gustafson
iii) Godfrey Hounsfield vi) Hargobind Khorana
c) Define the following: [2x1]
i) Heterosis ii) Standing state in an ecosystem
d) Give reasons for the following: [2]
i)Abiotic synthesis is not possible under present day condition.
ii)Offsprings of a blind couple are not always blind.
e)Multiple choice questions. Choose the best option in each case: [4x1]
, (ii)How many ova and sperms would be produced from 50 primary oocytes and
50 primary spermatocytes during gametogenesis? :
I.100 ova, 50 sperms II.100 ova, 200 sperms
III. 50 ova, 200 sperms IV.50 ova, 100 sperms
(iii)Which one of the following is a palindromic sequence? :
I.5’-CGTATG-3’ 3’CGAATG-5’
II.5’-CGAATG-3’ 3’-GCATAC-5’
III.5’-GAATTC-3’ 3’-CTTAAG-5’
IV.5’-GCAATG-3’ 3’-CTTAAG-5’
(iv)Assertion: Tapetum is the innermost wall layer. It performs the function of
providing nourishment to the developing pollen grains.
Reason: The cells of tapetum have dense cytoplasm and usually have more
than one nucleus.
I.Both assertion & reason are true and reason is the correct explanation of assertion.
II.Both assertion & reason are true, but reason is not the correct explanation of assertion.
III.Assertion is true and reason is false.
IV.Both assertion and reason are false.
PART II (50 Marks)
SECTION A (7x2=14 Marks)
Q.2 How does Reproductive and Child Health Care Program, run by
the government, benefit the society?
OR
Write any FOUR causes of infertility in males.
Q.3 Give an account of Darwin’s finches.
OR
CLASS XII BIOLOGY
MAX. MARKS: 70 TIME: 3 HRS
NAME____________ CLASS_____SECTION__________ ROLL NO.
This paper comprises of two Parts- I and II. Answer all Questions
PART I (20 Marks)
Q.1 (a) Answer the following as per instructions (Attempt all questions) : [8x1]
i)If a segment of double-stranded DNA has 18% thymine, calculate the
percentage of cytosine in the DNA.
ii)A woman has normal vision, but her father is colour-blind. If she marries
a colour-blind man, what is the probability of her son being colour-blind?
iii)What are Ramsar sites?
iv)Name the bond which exists between chain-A and chain-B of human
insulin.
v)Name the toxin responsible for causing the symptoms of malaria.
vi)Give the biological name of the causative agent of Syphilis.
vii)What are Analogous organs? Give ONE example from Plant Kingdom.
viii)What is the function of prostaglandins present in the secretion of
vesicle?
b)State the best known contributions of the following: [4x1]
i) Ernst Haeckel ii) Gustafson
iii) Godfrey Hounsfield vi) Hargobind Khorana
c) Define the following: [2x1]
i) Heterosis ii) Standing state in an ecosystem
d) Give reasons for the following: [2]
i)Abiotic synthesis is not possible under present day condition.
ii)Offsprings of a blind couple are not always blind.
e)Multiple choice questions. Choose the best option in each case: [4x1]
, (ii)How many ova and sperms would be produced from 50 primary oocytes and
50 primary spermatocytes during gametogenesis? :
I.100 ova, 50 sperms II.100 ova, 200 sperms
III. 50 ova, 200 sperms IV.50 ova, 100 sperms
(iii)Which one of the following is a palindromic sequence? :
I.5’-CGTATG-3’ 3’CGAATG-5’
II.5’-CGAATG-3’ 3’-GCATAC-5’
III.5’-GAATTC-3’ 3’-CTTAAG-5’
IV.5’-GCAATG-3’ 3’-CTTAAG-5’
(iv)Assertion: Tapetum is the innermost wall layer. It performs the function of
providing nourishment to the developing pollen grains.
Reason: The cells of tapetum have dense cytoplasm and usually have more
than one nucleus.
I.Both assertion & reason are true and reason is the correct explanation of assertion.
II.Both assertion & reason are true, but reason is not the correct explanation of assertion.
III.Assertion is true and reason is false.
IV.Both assertion and reason are false.
PART II (50 Marks)
SECTION A (7x2=14 Marks)
Q.2 How does Reproductive and Child Health Care Program, run by
the government, benefit the society?
OR
Write any FOUR causes of infertility in males.
Q.3 Give an account of Darwin’s finches.
OR
