NDA Diversity, heredity and evolution previous year questions with solutions

Answer: (c) Both 1 and 2

Method. Characteristics of living things

School reading (Class 10 Science, life processes): growth and repair and metabolism mark living things, so both statements hold. Non-living things can increase in size by accretion (Class 11 ch 1), but that is external addition, not growth from within, and no non-living thing repairs itself or has metabolism.

Non-living things can enlarge by accretion (Class 11 Biology ch 1), but that is not growth in the biological sense, and no non-living thing repairs itself; statement 1 stands.

Answer: (b) Panchanan Maheshwari

Method. Indian botanists

Panchanan Maheshwari, the Delhi embryologist, popularised embryological characters in taxonomy (standard Indian botany history; named fact, Class 11-12 Biology level). Linnaeus used sexual characters, Birbal Sahni was a palaeobotanist (NS12-A100), Bentham and Hooker devised a natural system.

Answer: (b) Amoeba proteus

Method. Binomial nomenclature rules

Genus name begins with a capital letter, species name entirely in small letters, both in italics when printed (NS12-A95). So Amoeba proteus is right; (a) capitalises the species, (c) does not capitalise the genus, (d) underlines and italicises together and capitalises the species.

Answer: (a) Phylum — Class — Order — Family — Genus

Method. Hierarchy of classification

Class 9 Science ch 12 (NS12-A89, A90): Kingdom, Phylum, Class, Order, Family, Genus, Species, each lower level sharing more features. Only (a) keeps Order above Family and Genus below Family.

Answer: (c) Can carry out photosynthesis

Method. Features of fungi (negative stem)

Fungi are heterotrophs that absorb food; they have chitin walls, mycelium of filaments and spores (NS12-A42, A45). They have no chlorophyll, so (c) is not a feature.

Answer: (c) Viruses can synthesize their food through photosynthesis.

Method. Viruses (negative stem)

The 'not true' statement is (c): viruses have no cell structure or chlorophyll and cannot photosynthesise. (a) and (b) are true, since viruses are obligate parasites that reproduce only in a host cell, and (d) is true, since outside a host they behave as inert crystallisable chemicals (standard, Class 11 Biology).

Answer: (c) Monera and Protista both

Method. Kingdoms and cell number

Monera (bacteria) and Protista are unicellular (NS12-A32, A38). Fungi include multicellular forms such as mushrooms and moulds (NS12-A42), so (d) is wrong. School reading: colonial protists are still treated as unicellular.

Answer: (b) chitin

Method. Fungal cell wall composition

Fungal cell walls are made of chitin (Class 9 Science ch 12, NS12-A42); plant cell walls are cellulose (NS12-A48). Cholesterol is an animal membrane lipid and glycogen is a storage carbohydrate, not wall materials.

Answer: (d) Bryophytes

Method. Ploidy of plant bodies

Bryophyte plant body is the haploid gametophyte, the dominant phase. Pteridophytes, gymnosperms and angiosperms have a diploid sporophyte as the dominant plant body (standard, Class 11 Biology, plant kingdom; compare NS12-A54).

Answer: (d) Specialized water-conducting tissues are present.

Method. Bryophytes (negative stem)

Bryophytes have no specialised water-conducting (vascular) tissue; xylem and phloem begin in pteridophytes (NS12-A54, A57, A63). The plant body is a gametophyte, held by rhizoids, and they are the 'amphibians' of the plant kingdom (NS12-A56). So (d) is the incorrect statement.

Answer: (a) Bryophytes

Method. Plant groups

Bryophytes need water for reproduction (the male gamete swims to the egg) though they live on land, hence the 'amphibians' of the plant kingdom (NS12-A56). Pteridophytes also need water but are the first vascular plants.

Answer: (d) Gymnosperms

Method. Gymnosperms

Gymnos means naked, spermos seed: gymnosperms such as pine and cycads bear naked seeds and are evergreen woody plants (NS12-A59). Angiosperms have seeds enclosed in fruit; pteridophytes bear no seeds (NS12-A57).

Answer: (c) Marsilea

Method. Vascular tissue in plant groups

Marsilea is a pteridophyte (aquatic fern) and has xylem and phloem (NS12-A57, A63). Cladophora is an alga, Penicillium a fungus, Anabaena a cyanobacterium: none has vascular tissue.

Answer: (d) Vascular system is not found among Bryophytes

Method. Plant classification

Bryophytes lack xylem and phloem (vascular tissue appears first in pteridophytes, NS12-A57, A63). Thallophytes have an undifferentiated thallus (NS12-A50, A54), so (a) is wrong; Funaria is a moss (bryophyte); pteridophytes are cryptogams, not phanerogams.

Answer: (b) II and III only

Method. External fertilisation

Frogs and most bony fishes shed eggs and sperm into water, so fertilisation is external. Pigeons (birds) and lizards (reptiles) have internal fertilisation, so only II and III (standard, Class 12 Biology, reproduction in organisms).

Answer: (c) Porifera

Method. Animal phyla

Sponges belong to phylum Porifera, the pore-bearers (NS12-A69). Coelenterata (Cnidaria) includes Hydra and jellyfish, Platyhelminthes the flatworms, Echinodermata the starfish.

Answer: (a) Dogfish

Method. Classes of animals

Dogfish is a (cartilaginous) fish, class Pisces. Jellyfish is a cnidarian (NS12-A71), starfish an echinoderm and silverfish an insect, so none of those is a fish despite the name.

Answer: (a) Four

Method. Ruminant stomach

Cattle, buffalo, goat and sheep are ruminants with a four-chambered stomach: rumen, reticulum, omasum and abomasum (standard, Class 11 Biology / animal husbandry; not an NCERT row of this chapter).

Answer: (a) Adenine pairs with Thymine

Method. DNA base pairing

In DNA adenine pairs with thymine (two hydrogen bonds) and guanine with cytosine (three) (standard, Class 12 Biology, molecular basis of inheritance; Class 10 C8-A25 on DNA as information source).

Answer: (b) Both chromosome number and DNA content remains constant

Method. Constancy of chromosome number

Gametes are haploid, so meiosis halves the number and fertilisation restores it; parent and offspring both have the same diploid chromosome number and DNA content (C8-A32: the DNA of the species stays stable). Neither number increases or decreases from generation to generation.

Answer: (c) Alleles

Method. Alleles

Alternative forms of the same gene are alleles (Class 10 Science ch 8, inheritance; C8-A11 on two versions of each trait, standard term). Genotype is the whole genetic constitution, isomers are chemical compounds.

Answer: (b) Maurice Hugh Frederick Wilkins

Method. Nobel Prize 1962, DNA structure

The 1962 Nobel Prize in Physiology or Medicine went to Crick, Watson and Maurice Wilkins (standard history of molecular biology). Rosalind Franklin's X-ray work was vital but she died in 1958 and the prize is not given posthumously; Chargaff (base ratios) and Levene (nucleotides) did not share it.

Answer: (a) Charles Darwin

Method. Authorship of a book

Charles Darwin wrote 'On the Origin of Species by Means of Natural Selection' (1859) (standard; Class 10 Science, evolution). Linnaeus is the binomial-nomenclature founder (NS12-A91), McClintock the discoverer of transposons.

Answer: (b) Meiosis and fertilization

Method. Genetic diversity in sexual reproduction

Meiosis shuffles and recombines chromosomes to form varied gametes, and fertilisation combines gametes from two parents (Class 10 Science ch 8, C8-A32). Mitosis and binary fission are asexual and copy the parent; conjugation is not a feature of higher organisms.

Answer: (d) more variation in offspring.

Method. Sexual reproduction and variation

Sexual reproduction combines DNA of two parents, so offspring show more variation (Class 10 Science ch 8, C8-A01, C8-A06). Variation helps some members survive environmental change, so the species persists over evolutionary time. Offspring number and 'robustness' are not what is claimed.