Test 1 (Class 12)- Recall (Old NCERT)

Biology 1 - Section A

1.

Zona pellucida is a membrane surrounding:

1.	Secondary oocyte	2.	Secondary follicle
3.	Corona Radiata	4.	Trophoblast cells

2.

“Saheli” is a:

1.	NGO working for female child rights
2.	Mid-wife working in villages to help with child immunization
3.	A national helpline number for the prevention of crimes against women
4.	New oral contraceptive for females

3.

The term ‘clone’ cannot be applied to offspring formed by sexual reproduction because:

1.	Offspring do not possess exact copies of parental DNA
2.	DNA of only one parent is copied and passed on to the offspring
3.	Offspring are formed at different times
4.	DNA of the parent and offspring are completely different.

4.

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A):	LH is necessary to maintain luteal function for the second two weeks of the menstrual cycle.
Reason (R):	If fertilization does not occur, LH is continued to be secreted in low concentration in the luteal phase.

In the light of the above statements, choose the most appropriate answer from the options given below :

1.	Both (A) and (R) are True and (R) is the correct explanation of (A).
2.	Both (A) and (R) are True but (R) is not the correct explanation of (A).
3.	(A) is True but (R) is False.
4.	Both (A) and (R) are False.

5.

Endospermic seeds are seen in:

1.	Bean	2.	Gram
3.	Pea	4.	Castor

6. Identify A-D in the given enlarged view of one microsporangium showing wall layers:

	A	B	C	D
1.	Epidermis	Endothecium	Middle layers	Tapetum
2.	Epithelium	Endothelium	Middle layers	Tapetum
3.	Endothecium	Epidermis	Tapetum	Middle layers
4.	Epithelium	Endothelium	Tapetum	Middle layers

7. Consider the given two statements:

Statement I:	Fragmentation in Hydra is an example of asexual mode of reproduction.
Statement II:	The body of Hydra breaks into distinct pieces [fragments] and each fragment grows into an adult capable of producing offspring.

1.	Statement I is correct; Statement II is correct.
2.	Statement I is incorrect; Statement II is incorrect.
3.	Statement I is incorrect; Statement II is correct.
4.	Statement I is correct; Statement II is incorrect.

8.

What is the number of chromosomes in each secondary spermatocyte?

1.	23	2.	46
3.	69	4.	92

9.

Corpus luteum secretes large amounts of:

1.	LH	2.	FSH
3.	Progesterone	4.	Estrogen

10. Match each item in Column I with one in Column II and select the correct match from the codes given:

	Column I		Column II
A.	Transfer of sperms into the female genital tract	P.	Fertilisation
B.	Embryonic development	Q.	Insemination
C.	Attachment of blastocyst to the uterine wall	R.	Gestation
D.	Fusion of male and female gametes	S.	Implantation

Codes:

	A	B	C	D
1.	P	Q	R	S
2.	R	Q	S	p
3.	Q	R	S	P
4.	S	P	R	Q

11.

What structure gets implanted on the wall of the uterus during embryonic development?

1.		2.
3.		4.

12.

What causes the onset of puberty in males?

1.	Increase in secretion of testosterone by the testis
2.	Decrease in the secretion of testosterone by the testis
3.	Increase in secretion of GnRH by the hypothalamus
4.	Decrease in the secretion of GnRH by the hypothalamus

13.

Consider the following two statements:

I:	Not all copulations lead to fertilization and pregnancy
II:	Fertilization can occur if the ovum and the sperms are simultaneously transported to the fallopian tubes.

1. Both I and II are correct and II correctly explains I.
2. Both I and II are correct but II does not explain I.
3. I is correct but II is incorrect.
4. I is incorrect but II is correct.

14.

The most important measure to check the population explosion in India is:

1.	Enforce one child norm by law with strict penalties for non-compliance
2.	Progressively increasing the statutory marriage age in males to 25 years
3.	Motivate smaller families by using contraceptive methods
4.	Allowing pre-natal sex determination to encourage selective feticide

15.

A typical angiosperm embryosac, at maturity, is:

1.	8 celled and 8 nucleate	2.	8 celled and 7 nucleate
3.	7 celled and 8 nucleate	4.	7 celled and 7 nucleate

16.

Double fertilization, a characteristic of angiosperms, results in the formation of:

1.	diploid zygote due to syngamy and triploid primary endosperm cell due to triple fusion
2.	triploid zygote due to triple fusion and diploid primary endosperm cell due to syngamy
3.	diploid zygote due to syngamy and haploid primary endosperm cell as it is formed pre-fertilization
4.	diploid zygote due to syngamy and diploid primary endosperm cell due to triple fusion

17. Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A):	An apomixis is a form of asexual reproduction that mimics sexual reproduction.
Reason (R):	There is no fertilisation in apomicts plants and they do not produce any seeds.

In the light of the above statements, choose the most appropriate answer from the options given below :

1.	(A) is True but (R) is False.
2.	Both (A) and (R) are True but (R) is not the correct explanation of (A).
3.	(A) is False but (R) is True.
4.	Both (A) and (R) are True and (R) is the correct explanation of (A).

Biology 1 - Section B

18.

Identify the incorrect statement regarding experiments on Pisum sativum by Gregor Mendel:

1.	He conducted hybridisation experiments on garden peas for seven years (1856-1863) and proposed the laws of inheritance in living organisms.
2.	It was for the first time that statistical analysis and mathematical logic were applied to problems in biology.
3.	Unfortunately his experiments had a small sampling size, which gave less credibility to the data that he collected.
4.	He investigated characters in the garden pea plant that were manifested as two opposing traits.

19.

Match each item in Column I with one in Column II and select your answer from the codes given:

	Column I		Column II
	Scientist		Contribution
A.	Francis Crick	a.	Breaking the genetic code
B.	Nirenberg	b.	Established Coenorhabditiselegans as a model genetics study organism
C.	Benzer	c.	Central dogma of molecular biology
D.	Brenner	d.	Bacteriophage genetics

Codes:

	A.	B.	C.	D.
1.	c	a	d	b
2.	c	a	b	d
3.	a	b	c	d
4.	a	c	d	b

20.

Suppose a gene has seven alleles. What would be the number of alleles in an individual at any instant?

1.	1	2.	7
3.	2	4.	3

21.

The inheritance of I^A and I^B allele exhibit:

1.	Complete dominance	2.	Incomplete dominance
3.	Co-dominance	4.	Lethality

22.

In true breeding, the allelic pair of genes are:

1.	Homologous	2.	Linked
3.	Stable	4.	Homozygous

23.

Which of the following sexually transmitted infections is completely curable if diagnosed and treated early?

1.	Hepatitis B	2.	Syphilis
3.	Genital herpes	4.	HIV

24.

ART [used to help infertile couples] stands for:

1.	Assisted Reproductive Technologies
2.	Artificial Reproductive Technologies
3.	Augmented Reproductive Technologies
4.	Anomalous Reproductive Technologies

25. The figure shows the diagrammatic representation of a test cross. Based on the results shown, what would be true?

Statement I:	In situation A, the plant with the dominant phenotype [genotype unknown] must be homozygous dominant.
Statement II:	In situation B, the plant with the dominant phenotype [genotype unknown] must be heterozygous.

1. Only Statement I
2. Only Statement II
3. Both Statement I and Statement II
4. Neither Statement I nor Statement II

Biology 2 - Section A

26.

Which of the following is true for both transcription and DNA replication?

1.	The principle of complementarity governs the processes
2.	Only if the two strands act as a template
3.	Only a segment of both strands is involved
4.	Adenine base pairs with thymine

27.

To form a nucleoside, a nitrogenous base is linked to a pentose sugar:

1.	Through a P-Glycosidic linkage at carbon atom number 1
2.	Through a P-Glycosidic linkage at carbon atom number 5
3.	Through an N-Glycosidic linkage at carbon atom number 1
4.	Through an N-Glycosidic linkage at carbon atom number 5

28. Thalassemia can be classified according to which chain of the haemoglobin molecule is affected.

Statement I:	α Thalassemia is controlled by a single gene HBB on chromosome 11 of each parent and occurs due to mutation of one or both the genes.
Statement II:	β Thalassemia is controlled by two closely linked genes HBA1 and HBA2 on chromosome 16 of each parent.

1. Statement I is correct, Statement II is correct.
2. Statement I is incorrect, Statement II is correct.
3. Statement I is correct, Statement II is incorrect.
4. Statement I is incorrect, Statement II is incorrect.

29.

The discontinuously synthesized DNA fragments are later joined by:

1.	DNA helicase	2.	Topoisomerase
3.	DNA ligase	4.	DNA polymerase

30.

During his observation of spermatogenesis in a few insects, Henking found that a nuclear structure was received by 50 % of the sperms. He called this structure as:

1.	X – body	2.	Y–body
3.	X – chromosome	4.	Y – chromosome

31.

Some amino acids are coded by more than one codon. Hence genetic code is:

1.	Unambiguous	2.	Non-specific
3.	Degenerate	4.	Universal

32.

In a transcription unit, with respect to structural genes, the promoter is located:

1.	Upstream and 5’	2.	Upstream and 3’
3.	Downstream and 5’	3.	Downstream and 3’

33.

A dihybrid test cross results in a recombination frequency of 50%. Most likely the two genes under consideration:

1.	are closely linked on the same autosome
2.	are located on heterologous chromosomes
3.	are present on the X chromosome
4.	are located on the same chromosome, one on either side of the centromere

34. Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A):	S-strain of Streptococcus pneumoniae is virulent.
Reason (R):	Heat-killed S-strain Streptococcus pneumoniae injected into mice did not cause pneumonia and did not kill them.

In the light of the above statements, choose the most appropriate answer from the options given below :

1.	Both (A) and (R) are True and (R) is the correct explanation of (A).
2.	(A) is True but (R) is False.
3.	Both (A) and (R) are True but (R) is not the correct explanation of (A).
4.	Both (A) and (R) are False.

35.

The distance between a base pair in the DNA double helix is approximately:

1.	2.0 nm	2.	0.34 nm
3.	20 nm	4.	3.4 nm

36.

The source of any of the genes located on either of the X chromosomes in a female cannot be:

1.	Her Mother's Father.	2.	Her Father's Mother.
3.	Her Mother's Mother.	4.	Her Father's Father.

37. Although gene expression in eukaryotes can take place at multiple levels. The most common level of gene expression would be:

1.	transcriptional level (formation of the primary transcript)
2.	processing level (regulation of splicing)
3.	transport of mRNA from the nucleus to the cytoplasm
4.	translational level

38.

A trait displays continuous phenotypic variation and is spread across a gradient. Usually, the inheritance of this trait can be described as:
1. dominant-recessive inheritance
2. multiple-allele inheritance
3. polygenic inheritance
4. sex-linked inheritance

39.

The last of 24 human chromosomes to be sequenced was:
1. Chromosome 1 and completed in 2003
2. Chromosome 1 and completed in 2006
3. Chromosome X and completed in 2003
4. Chromosome X and completed in 2006

40.

If E.coli was allowed to grow for 80 minutes after transfer from ¹⁵N to ¹⁴N medium, the number of hybrid density DNA molecules would be:

1.	2	2.	16
3.	14	4.	8

41. Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A):	An adapter molecule, that on one hand can read the genetic code and on the other hand can bind to specific amino acids, is required for the translation of proteins.
Reason (R):	Amino acids have no structural specialties to read the code uniquely.

In the light of the above statements, choose the most appropriate answer from the options given below :

1.	Both (A) and (R) are True and (R) is the correct explanation of (A).
2.	Both (A) and (R) are False.
3.	Both (A) and (R) are True but (R) is not the correct explanation of (A).
4.	(A) is True but (R) is False.

42.

The inheritance of the trait shown in the given pedigree most likely is:

1.	Autosomal recessive	2.	Autosomal dominant
3.	Sex-linked recessive	4.	Sex-linked dominant

Biology 2 - Section B

43.

In a population in genetic equilibrium, the frequency of the recessive allele is found to be 0.2. What is the frequency of heterozygotes in this population?

1.	0.8	2.	0.16
3.	0.32	4.	0.64

44. Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A):	Repetitive units of DNA, micro-satellites, and mini-satellites are the basis of DNA fingerprinting.
Reason (R):	DNA fingerprinting is the basis of paternity testing, in cases of disputes.

In the light of the above statements, choose the most appropriate answer from the options given below :

1.	Both (A) and (R) are True but (R) is not the correct explanation of (A).
2.	Both (A) and (R) are False.
3.	Both (A) and (R) are True and (R) is the correct explanation of (A).
4.	(A) is True but (R) is False.

45. Fossils are generally found in:
1. Sedimentary rocks
2. Igneous rocks
3. Metamorphic rocks
4. Any type of rock

46.

The wings of birds, the forelegs of a horse, and the upper limbs of humans are:

1.	analogous structures	2.	homologous structures
3.	vestigial structures	4.	phylogenetic structures

47. Identify the incorrect statement:

1.	Neanderthals lived between 1,50,000 and 1,00,000 years back.
2.	Modern Homo sapiens arose between 75000 and 10000 years ago.
3.	Pre-historic cave art developed around 18000 years ago.
4.	Agriculture came around 10000 years ago

48. The connotations about the theory of special creation include:

I:	All living organisms (species or types) that we see today were created as such.
II:	Diversity was always the same since creation and will be the same in the future also.
III:	Earth is about 4 billion years old.

1. Only I and II are correct
2. Only I and III are correct
3. Only II and III are correct
4. I, II and III are correct

49.

Genetic drift is :

1.	random changes in gene frequency in a population
2.	generational fluctuations in gene frequencies that produce no effect
3.	changes due to interbreeding with other species populations
4.	the effect of mutations as they spread through neighbouring populations

50.

The process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography [habitats] is known as:

1.	Convergent evolution	2.	Divergent evolution
3.	Adaptive radiation	4.	Artificial selection

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