NEET 2020 — Botany

All 44 Botany questions we hold from this paper, of the 180 on the site for this sitting — every option and the answer key. 4 marks each, −1 for a wrong answer.

Botany

45 questions, one correct option each. +4 for a correct answer, −1 for a wrong one, nothing for a blank.

Q1 open Organisms and Populations · Population attributes, growth models and interactions

Which of the following is not an attribute of a population?

A.Sex ratio
B.Natality
C.Mortality
D.Species interaction✓

The worked solution is part of a paid pack.

Q2 open Plant Growth and Development · Phases of growth and differentiation

The process of growth is maximum during:

A.Log phase✓
B.Lag phase
C.Senescence
D.Dormancy

The worked solution is part of a paid pack.

Q3 open Morphology of Flowering Plants · Root, stem and leaf: modifications

The roots that originate from the base of the stem are:

A.Fibrous roots✓
B.Primary roots
C.Prop roots
D.Lateral roots

The worked solution is part of a paid pack.

Q4 open Principles of Inheritance and Variation · Mendel's laws and deviations

Identify the wrong statement with reference to the gene 'I' that controls ABO blood groups.

A.The gene (I) has three alleles
B.A person will have only two of the three alleles
C.When $I^{A}$ and $I^{B}$ are present together, they express the same type of sugar✓
D.Allele 'i' does not produce any sugar

The worked solution is part of a paid pack.

Q5 open Principles of Inheritance and Variation · Sex determination, mutation, genetic disorders

Select the correct match.

A.Haemophilia – Y-linked
B.Phenylketonuria – Autosomal dominant trait
C.Sickle cell anaemia – Autosomal recessive trait, chromosome-11✓
D.Thalassemia – X-linked

The worked solution is part of a paid pack.

Q6 open Sexual Reproduction in Flowering Plants · Post-fertilisation: embryo, seed, fruit; apomixis

The plant parts which consist of two generations, one within the other:

(a) Pollen grains inside the anther

(b) A germinated pollen grain with two male gametes

(d) An embryo sac inside the ovule

A.(a) only
B.(a), (b) and (c)
C.(c) and (d)
D.(a) and (d)✓

The worked solution is part of a paid pack.

Q7 open

The product(s) of the reaction catalysed by nitrogenase in the root nodules of leguminous plants is/are:

A.Ammonia alone
B.Nitrate alone
C.Ammonia and oxygen
D.Ammonia and hydrogen✓

The worked solution is part of a paid pack.

Q8 open Cell Cycle and Cell Division · Phases of the cell cycle

Identify the correct statement with regard to the $G_{1}$ phase (Gap 1) of interphase.

A.DNA synthesis or replication takes place
B.Reorganisation of all cell components takes place
C.The cell is metabolically active and grows, but does not replicate its DNA✓
D.Nuclear division takes place

The worked solution is part of a paid pack.

Q9 open Cell: The Unit of Life · Cell theory, prokaryotic and eukaryotic cells

Which of the following statements about inclusion bodies is incorrect?

A.They are not bound by any membrane
B.These are involved in ingestion of food particles✓
C.They lie free in the cytoplasm
D.These represent reserve material in the cytoplasm

The worked solution is part of a paid pack.

Q10 open Cell: The Unit of Life · Cell membrane, cell wall and endomembrane system

Which is the important site of formation of glycoproteins and glycolipids in eukaryotic cells?

A.Endoplasmic reticulum
B.Peroxisomes
C.Golgi bodies✓
D.Polysomes

The worked solution is part of a paid pack.

Q11 open Morphology of Flowering Plants · Inflorescence, flower and floral formula

Ray florets have:

A.An inferior ovary✓
B.A superior ovary
C.A hypogynous ovary
D.A half-inferior ovary

The worked solution is part of a paid pack.

Q12 open Microbes in Human Welfare · Sewage treatment, biogas, biocontrol and biofertilisers

Which of the following is put into the anaerobic sludge digester for further sewage treatment?

A.Primary sludge
B.Floating debris
C.Effluents of primary treatment
D.Activated sludge✓

The worked solution is part of a paid pack.

Q13 open

Match the following, concerning essential elements and their functions in plants.

Element	Function
(a) Iron	(i) Photolysis of water
(b) Zinc	(ii) Pollen germination
(c) Boron	(iii) Required for chlorophyll biosynthesis
(d) Manganese	(iv) IAA biosynthesis

Select the correct option:

A.(a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
B.(a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)
C.(a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)✓
D.(a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)

The worked solution is part of a paid pack.

Q14 open Anatomy of Flowering Plants · Anatomy of dicot and monocot root, stem, leaf

Identify the incorrect statement.

A.Heartwood does not conduct water but gives mechanical support
B.Sapwood is involved in the conduction of water and minerals from root to leaf
C.Sapwood is the innermost secondary xylem and is lighter in colour✓
D.Due to the deposition of tannins, resins, oils etc., heartwood is dark in colour

The worked solution is part of a paid pack.

Q15 open Biodiversity and Conservation · Levels and patterns of biodiversity

According to Robert May, the global species diversity is about:

A.1.5 million
B.20 million
C.50 million
D.7 million✓

The worked solution is part of a paid pack.

Q16 open Molecular Basis of Inheritance · Transcription, genetic code, translation

The first phase of translation is:

A.Binding of mRNA to the ribosome
B.Recognition of the DNA molecule
C.Aminoacylation of tRNA✓
D.Recognition of an anti-codon

The worked solution is part of a paid pack.

Q17 open Biodiversity and Conservation · Levels and patterns of biodiversity

Which of the following regions of the globe exhibits the highest species diversity?

A.Western Ghats of India
B.Madagascar
C.Himalayas
D.Amazon forests✓

The worked solution is part of a paid pack.

Q18 open Anatomy of Flowering Plants · Anatomy of dicot and monocot root, stem, leaf

The transverse section of a plant part shows the following anatomical features:

(a) A large number of scattered vascular bundles surrounded by a bundle sheath

(b) Large, conspicuous parenchymatous ground tissue

(d) Phloem parenchyma absent

Identify the category of plant and its part:

A.Monocotyledonous stem✓
B.Monocotyledonous root
C.Dicotyledonous stem
D.Dicotyledonous root

The worked solution is part of a paid pack.

Q19 open

The process responsible for facilitating the loss of water in liquid form from the tip of grass blades at night and in early morning is:

A.Transpiration
B.Root pressure✓
C.Imbibition
D.Plasmolysis

The worked solution is part of a paid pack.

Q20 open

Secondary metabolites such as nicotine, strychnine and caffeine are produced by plants for their:

A.Nutritive value
B.Growth response
C.Defence action✓
D.Effect on reproduction

The worked solution is part of a paid pack.

Q21 open Photosynthesis in Higher Plants · Calvin cycle, C4 pathway, photorespiration

The oxygenation activity of the RuBisCO enzyme in photorespiration leads to the formation of:

A.2 molecules of a 3-C compound
B.1 molecule of a 3-C compound✓
C.1 molecule of a 6-C compound
D.1 molecule of a 4-C compound and 1 molecule of a 2-C compound

The worked solution is part of a paid pack.

Q22 open Microbes in Human Welfare · Microbes in household and industrial products

Match the following columns and select the correct option.

Microbe	Product
(a) Clostridium butylicum	(i) Cyclosporin-A
(b) Trichoderma polysporum	(ii) Butyric acid
(c) Monascus purpureus	(iii) Citric acid
(d) Aspergillus niger	(iv) Blood-cholesterol-lowering agent

A.(a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)
B.(a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)✓
C.(a)-(i), (b)-(ii), (c)-(iv), (d)-(iii)
D.(a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)

The worked solution is part of a paid pack.

Q23 open Plant Kingdom · Algae

Floridean starch has a structure similar to:

A.Starch and cellulose
B.Amylopectin and glycogen✓
C.Mannitol and algin
D.Laminarin and cellulose

The worked solution is part of a paid pack.

Q24 open Cell Cycle and Cell Division · Meiosis and its significance

Match the following with respect to meiosis.

Stage	Feature
(a) Zygotene	(i) Terminalisation
(b) Pachytene	(ii) Chiasmata
(c) Diplotene	(iii) Crossing over
(d) Diakinesis	(iv) Synapsis

Select the correct option:

A.(a)-(iii), (b)-(iv), (c)-(i), (d)-(ii)
B.(a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)✓
C.(a)-(i), (b)-(ii), (c)-(iv), (d)-(iii)
D.(a)-(ii), (b)-(iv), (c)-(iii), (d)-(i)

The worked solution is part of a paid pack.

Q25 open Plant Kingdom · Algae

Which of the following pairs is of unicellular algae?

A.Laminaria and Sargassum
B.Gelidium and Gracilaria
C.Anabaena and Volvox
D.Chlorella and Spirulina✓

The worked solution is part of a paid pack.

Q26 open

The Montreal Protocol was signed in 1987 for the control of:

A.Transport of genetically modified organisms from one country to another
B.Emission of ozone-depleting substances✓
C.Release of greenhouse gases
D.Disposal of e-waste

The worked solution is part of a paid pack.

Q27 open Biological Classification · Viruses, viroids and lichens

Which of the following is correct about viroids?

A.They have RNA with a protein coat
B.They have free RNA without a protein coat✓
C.They have DNA with a protein coat
D.They have free DNA without a protein coat

The worked solution is part of a paid pack.

Q28 open Morphology of Flowering Plants · Inflorescence, flower and floral formula

The ovary is half-inferior in:

A.Brinjal
B.Mustard
C.Sunflower
D.Plum✓

The worked solution is part of a paid pack.

Q29 open Ecosystem · Energy flow, ecological pyramids

Match the trophic levels with their correct species examples in a grassland ecosystem.

Trophic level	Example
(a) Fourth trophic level	(i) Crow
(b) Second trophic level	(ii) Vulture
(c) First trophic level	(iii) Rabbit
(d) Third trophic level	(iv) Grass

Select the correct option:

A.(a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)✓
B.(a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)
C.(a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)
D.(a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)

The worked solution is part of a paid pack.

Q30 open Principles of Inheritance and Variation · Mendel's laws and deviations

How many true-breeding pea plant varieties, similar except in one character with contrasting traits, did Mendel select as pairs?

A.4
B.2
C.14✓
D.8

The worked solution is part of a paid pack.

Q31 open Sexual Reproduction in Flowering Plants · Pollination and double fertilisation

In water hyacinth and water lily, pollination takes place by:

A.Insects or wind✓
B.Water currents only
C.Wind and water
D.Insects and water

The worked solution is part of a paid pack.

Q32 open Plant Growth and Development · Plant growth regulators: auxin, gibberellin, cytokinin, ethylene, ABA

Name the plant growth regulator which, upon spraying on a sugarcane crop, increases the length of the stem, thus increasing the yield of the sugarcane crop.

A.Cytokinin
B.Gibberellin✓
C.Ethylene
D.Abscisic acid

The worked solution is part of a paid pack.

Q33 open Photosynthesis in Higher Plants · Light reaction: photosystems, electron transport, photophosphorylation

In the light reaction, plastoquinone facilitates the transfer of electrons from:

A.PS II to the $Cyt b_{6} f$ complex✓
B.The $Cyt b_{6} f$ complex to PS I
C.PS I to $NAD P^{+}$
D.PS I to ATP synthase

The worked solution is part of a paid pack.

Q34 open Plant Growth and Development · Plant growth regulators: auxin, gibberellin, cytokinin, ethylene, ABA

Which of the following is not an inhibitory substance governing seed dormancy?

A.Gibberellic acid✓
B.Abscisic acid
C.Phenolic acid
D.Para-ascorbic acid

The worked solution is part of a paid pack.

Q35 open Molecular Basis of Inheritance · Transcription, genetic code, translation

Name the enzyme that facilitates the opening of the DNA helix during transcription.

A.DNA ligase
B.DNA helicase
C.DNA polymerase
D.RNA polymerase✓

The worked solution is part of a paid pack.

Q36 open Ecosystem · Structure, productivity and decomposition

In relation to the gross primary productivity and net primary productivity of an ecosystem, which one of the following statements is correct?

A.Gross primary productivity is always less than net primary productivity
B.Gross primary productivity is always more than net primary productivity✓
C.Gross primary productivity and net primary productivity are one and the same
D.There is no relationship between gross primary productivity and net primary productivity

The worked solution is part of a paid pack.

Q37 open Plant Kingdom · Bryophytes and pteridophytes

Strobili or cones are found in:

A.Salvinia
B.Pteris
C.Marchantia
D.Equisetum✓

The worked solution is part of a paid pack.

Q38 open Cell Cycle and Cell Division · Phases of the cell cycle

Some dividing cells exit the cell cycle and enter a vegetative, inactive stage. This is called the quiescent stage ( $G_{0}$ ). This process occurs at the end of:

A.M phase
B. $G_{1}$ phase✓
C.S phase
D. $G_{2}$ phase

The worked solution is part of a paid pack.

Q39 open Molecular Basis of Inheritance · DNA structure and replication

If the distance between two consecutive base pairs is 0.34 nm and the total number of base pairs of a DNA double helix in a typical mammalian cell is $6.6 \times 1 0^{9}$ bp, then the length of the DNA is approximately: