Biology Outside Delhi Set - 2 2023-2024 Science (English Medium) Class 12 Question Paper Solution

In a fertilized ovule of an angiosperm, the cells in which n, 2n and 3n conditions respectively occur are ______.

Antipodal, zygote and endosperm

Zygote, nucellus and endosperm

Endosperm, nucellus and zygote

Antipodals, synergids and integuments

Turner’s syndrome in humans occurs due to 

Aneuploidy

Euploidy

Polyploidy

Autosomal abnormality

Which of the options has correct identification of ‘P’, ‘Q’ and ‘R’ in the illustration of ‘Central Dogma’ given below?

P – Replication, Q – rRNA, R – Transcription

P – Translation, Q – mRNA, R – Transcription

P – Replication, Q – mRNA, R – Translation

P – Transcription, Q – mRNA, R – Translation

Study the following diagram of Transverse Section of a young anther of an angiosperm:

Select the option where parts ‘A’, ‘B’ and ‘C’ are correctly identified.

A – Connective, B – Endothecium, C – Pollen grain.

A – Endothecium, B – Connective, C – Pollen grain.

A – Pollen grain, B – Connective, C – Endothecium.

A – Endothecium, B – Pollen grain, C – Connective.

Select the option that gives the correct identification of ovum, morula and blastocyst in a human female reproduction system, as shown in the following diagram:

Ovum – B, Morula – D, Blastocyst – F

Ovum – A, Morula – B, Blastocyst – G

Ovum – A, Morula – E, Blastocyst – G

Ovum – B, Morula – D, Blastocyst – G

Study the table given below:

Select the option where contraceptive/contraceptive method are correctly matched with their mode of action.

A – III, B – II, C – I, D – IV

A – II, B – III, C – I, D – IV

A – III, B – I, C – IV, D – II

A – IV, B – III, C – II, D – I

Identify the category of genetic disorder depicted in the pedigree chart given below:

X-Linked recessive

X-Linked dominant

Autosomal recessive

Autosomal dominant

ELISA technique is based on the principle of ______.

DNA replication

Antigen-antibody interaction

Pathogen–antigen interaction

Antigen–protein interaction

Homologous organs indicate ______.

Convergent evolution

Divergent evolution

Adaptive radiation

Natural selection

The ‘molecular scissors’ fall in the category of ______.

Cleaving enzyme

Endonuclease

Exonuclease

Restriction enzymes

Which of the chromosome in a human possesses the least number of genes?

21^st chromosome

16^th chromosome

X-chromosome

Y-chromosome

Given below are the list of the commercially important products and their source organisms. Select the option that gives the correct matches. 

(A) - (i), B - (ii), (C) - (iii), (D) - (iv)

(A) - (iii), B - (iv), (C) - (ii), (D) - (i)

(A) - (iv), B - (iii), (C) - (ii), (D) - (i)

(A) - (ii), B - (iv), (C) - (i), (D) - (iii)

Assertion (A): Plasmids are autonomously replicating circular extra-chromosomal DNA.

Reason (R): Plasmids are usually present in Eukaryotic cells.

Both (A) and (R) are true and (R) is the correct explanation of (A).

Both (A) and (R) are true and (R) is not the correct explanation of (A).

(A) is true, but (R) is false.

(A) is false, but (R) is true.

Assertion (A): Patents are granted by government to an inventor.

Reason (R): Patents prevents others from commercial use of an invention.

Both (A) and (R) are true and (R) is the correct explanation of (A).

Both (A) and (R) are true and (R) is not the correct explanation of (A).

(A) is true, but (R) is false.

(A) is false, but (R) is true.

Assertion (A): A given fig species can be pollinated only by its partner’ wasp.

Reason (R): The wasp pollinates the fig inflorescence while searching for suitable egg laying sites.

Both (A) and (R) are true and (R) is the correct explanation of (A).

Both (A) and (R) are true and (R) is not the correct explanation of (A).

(A) is true, but (R) is false.

(A) is false, but (R) is true.

Assertion (A): Some aquatic ecosystems have inverted biomass pyramids.

Reason (R): More energy is required by the organisms occupying higher trophic levels.

Both (A) and (R) are true and (R) is the correct explanation of (A).

Both (A) and (R) are true and (R) is not the correct explanation of (A).

(A) is true, but (R) is false.

(A) is false, but (R) is true.

What is artificial insemination in ART?

Under what conditions is the person medically advised to go for artificial insemination in ART?

Why does a patient of ADA - deficiency require repeated infusions of genetically engineered lymphocytes?

Suggest a possible permanent remedy for ADA deficiency.

Study the graph given below that represents the changes in the thickening of the uterine wall in women ‘X’ and women ‘Y’ over a period of one month:

What does the graph with respect to woman ‘X’ and woman ‘Y’ indicate? Give suitable reason.

Biodiversity hotspots cover less than 2% of Earth’s land area. Strict protection of these areas can reduce the rate of ongoing extinctions. Explain.

Name any two biodiversity hot spots in India.

Differentiate between grazing food chain and detritus food chain.

What is brood parasitism? Explain with the help of an example.

With reference to flower colour two independent crosses were made, one between true breeding garden pea plants and another between true breeding Antirrhinum plants. Write the phenotypes of their F₁-progeny. Justify your answer giving reason.

Draw a well labelled diagram of sectional view of male gametophyte/microspore of an angiosperm and write the functions of any two parts labelled. (Any four labels).

1. Name the group of drugs whose skeletal molecule is shown below:             [1]
   
2. How are such drugs consumed?             [1]
3. Name the human body organ affected by the consumption of these drugs.              [1]

Explain the role of transgenic animals in production of biological products.

Explain the role of transgenic animals in studying diseases.

Explain the role of transgenic animals in chemical safety testing.

The schematic representation as above is showing the linking of two DNA fragments.

1. Name ‘A’ and ‘B’ fragments.      [1]
2. Write the ‘palindrom’ recognised by EcoRI.        [1]
3. Where does EcoRI cut the palindrome? Write the events followed thereafter to form a recombinant DNA.       [1]

How do the Mycorrhiza organisms act as bio-fertilisers? Explain.

How do the Anabaena organisms act as bio-fertilisers? Explain.

How do the Rhizobium organisms act as bio-fertilisers? Explain.

Whose skulls ‘A’, ‘B’, and ‘C’ are shown below? Which of the two are more similar to each other?

Name the ape-like primates that existed 1.5 million years ago.

Name the man-like primates that existed 1.5 million years ago.

Read the following passage:

1. Name this RNA product transcribed from the DNA that subsequently translates into a polypeptide of 400 amino acids. Mention the enzyme responsible for transcribing this type of RNA from the DNA.     [1]
2. Name and explain the process the RNA molecule transcribed from 8000 nucleotide long DNA undergoes to be able to translate a polypeptide of 400 amino acids.     [2]
3. Write the number of RNA polymerases involved in the transcription of DNA in a prokaryote and eukaryotes.     [1]
   OR
   Mention the difference in the site of transcription in a prokaryote and eukaryote cell.     [1]

Read the following passage:

Study the population growth curves shown in the given graph and answer the questions that follow:

1. Identify the growth curves ‘A’ and ‘B’.     [1]
2. Mention what does the dotted line in the graph indicate and state its importance also.      [1]
   OR
   Growth curve ‘B’ shows a different pattern from that of growth curve ‘A’. Justify giving one reason.      [1]
3. 
   
   1. Which one of the two curves is more “realistic” and why?      [1]
   2. Which one of the two curves is relevant in present days with respect to human population in our country and why?     [1]

Explain the menstruation phases in the menstrual cycle of a human female.

Explain the follicular phases in the menstrual cycle of a human female.

Explain the luteal phases in the menstrual cycle of a human female.

'A proper understanding of the menstrual cycle can help immensely in family planning.' Do you agree with the statement? Provide reasons for your answer.

Why does endosperm development precede embryo development in angiosperm seeds?

State the role of endosperm in mature albuminous seeds.

Draw a labelled diagram showing the different embryonic stages of a dicot plant, up to a fully mature embryo.

Describe the life cycle of HIV from the time of its entry into the human body till full blown AIDS sets in.

Write the symptoms of malaria in humans.

Explain what causes malaria in human symptoms.

Describe the different steps in the sexual mode of reproduction in the life cycle of a malarial parasite from the time of its initiation till where it is completed and ready to start a fresh cycle.

Study the schematic diagram given below and answer the questions that follow:

1. Identify the polarity from 'X' to '`bar(X)`' in the mRNA segment shown. Mention how many more amino acids can be added to the polypeptide that is being translated and why.        [1.5]
2. Write the initiating codon for translation, its anticodon and the amino acid it codes for.        [1.5]
3. Explain the charging of an adaptor molecule. Why this molecule needs to be charged?         [1]

Why is sickle-cell anaemia, a human blood disorder so named?

Explain the genetic basis that results in the expression of sickle-cell anaemia disorder.

Work out a cross to explain how normal parents may have a sickle-cell anaemic child.