NEET : Biology (Botany) : 2020- Exam Mode

Natality – Population attribute
Mortality – Population attribute
Species interaction – Population interaction
Sex ratio – Population attribute

In exponential growth, the initial growth is slow (lag phase) and it increases rapidly thereafter at an exponential rate in log or exponential phase.

The roots that originate from the base of the stem are fibrous roots.

Typhoid fever in humans is caused by pathogenic bacterium Salmonella typhi.
Pneumonia is caused by Streptococcus Pneumoniae and Haemophilus influenzae.
Filariasis or elephantiasis is caused by the filarial worm, Wuchereria bancrofti and Wuchereria malayi.
Malaria is caused by different species of Plasmodium.

Option (1) is the Answer because ART in which embryos are transferred, include ZIFT and IUT i.e. Zygote Intrafallopian Transfer and Intra Uterine Transfer respectively, both are embryo transfer (ET) methods.
Option (2), (3) and (4) are incorrect because in GIFT (Gamete Intrafallopian Transfer), gamete is transferred into the fallopian tube of female who cannot produce ova. ICSI is Intra cytoplasmic sperm injection in which sperm is directly injected into the ovum.

ABO blood groups are controlled by the gene I. The gene I has three alleles I^A , I^B and i. The alleles I^A and I^B produce a slightly different form of the sugar while allele i does not produce any sugar. Because humans are diploid organisms, each person can possess at the most any two of the three I gene alleles.

Ligases join the two DNA molecules.

Phenylketonuria – Autosomal recessive disorder
Thalassemia – Autosomal recessive disorder
Haemophilia – X linked recessive disorder
Sickle cell anaemia – Autosomal recessive trait, caused due to mutation in gene present on chromosome no. 11

(a) Locusta is a gregareous pest.
(b) In Echinoderms, adults are radially symmetrical but larvae are bilaterally symmetrical.
(c) Scorpions respire through book lungs.
(d) Bioluminescence is well marked in ctenophores.

Plasmodium enters the human body as sporozoites (Infectious stage) through the bite of Infected Female Anopheles mosquito.

Inulin is a fructan (polysaccharide of fructose). Adjacent fructose units are linked through glycosidic bond.
Insulin is a protein composed of 51 aminoacids. Adjacent aminoacids are attached through peptide bond.

The plant parts which consist of two generations one within the other are pollen grains inside the anther and embryo sac inside the ovule.
Pollen grain is haploid inside the diploid anther.
Embryo sac is haploid inside the diploid ovule.

N₂ + 8e^– + 8H⁺ + 16ATP     —- (Mg⁺⁺)–> 2NH₃ + H₂ + 16ADP + 16Pi
Ammonia and Hydrogen.

During G1 phase the cell is metabolically active and continuously grows but does not replicate its DNA.
DNA synthesis takes place in S phase. Nuclear division occurs during Karyokinesis.
Reorganisation of all cell components takes place in M-Phase.

Cuboidal epithelium with brush border of microvilli is found in proximal convoluted tubule of nephron (PCT).

These are not involved in ingestion of food particles.

Golgi bodies are site of formation of glycoproteins and glycolipids in eukaryotic cells.

The separated DNA fragments can be visualized only after staining the DNA with Ethidium bromide followed by exposure to UV radiation.

The correct option is {Higher H+ conc. in alveoli favours the formation of oxyhaemoglobin} because higher H+ concentration favours the dissociation of oxygen from oxyhaemoglobin in tissues.
In the alveoli, high pO₂, low pCO₂, lesser H+ concentration and lower temperature favour formation of oxyhaemoglobin.

• Ray floret have inferior ovary.
• Epigynous flower are formed in family Asteraceae (e.g., Sunflower)

The correct option is 5′ – GAATTC – 3′ 3′ – CTTAAG – 5′  because the specifi palindromic sequence which is recognised by
EcoRI is

5′ – GAATTC – 3′

3′ – CTTAAG – 5′

Restriction endonucleases make cuts at specific positions within the DNA.
They function by inspecting the length of a DNA sequence.
Restriction endonuclease bind to the DNA and cut the two strands of double helix at specific points in their sugar-phosphate backbones.
They are used in genetic engineering to form recombinant molecules of DNA.
DNA ligases join the DNA fragments.

The sediment in settlement tank is called activated sludge.
A small part of the activated sludge is pumped back into aeration tank
Remaining major part of the sludge is pumped into large tank called anaerobic sludge digesters.

Inspiration is initiated by the contraction of diaphragm, which increases the volume of thoracic chamber in the anterio-posterior axis.
The contraction of external intercostal muscles increase the volume of the thoracic chamber in the dorsoventral axis.

The head holds a small proportion of a nervous system while the rest is situated along the ventral part of its body.

In vertebrata, notochord is present during embryonic period only as it is replaced by vertebral column.
In chordates, central nervous system is dorsal and hollow.

(a) Bacillus thuringiensis is a source of Cryproteins.
(b) Thermus aquaticus is a source of thermostable DNA polymerase (Taq polymerase) used in PCR.
(c) Agrobacterium tumefaciens is a cloning vector.
(d) The construction of 1st recombinant DNA molecule was performed using native plasmid of Salmonella typhimurium.

(a) Iron – Essential for the formation of chlorophyll
(b) Zinc – Needed for synthesis of auxin
(c) Boron – Have a role in pollen grain germination
(d) Manganese – Is involved in the splitting of water to liberate O₂ during photosynthesis

Incorrect statement: Sapwood is the innermost secondary xylem and is lighter in color.
Correct statement: Sapwood is outermost secondary xylem.

Option a->(ii), b->(iv), c->(iii), d->(i) is correct because

Malonate is the competitive inhibitor of catalytic activity of succinic dehydrogenase, so (a) matches with (ii) in column II.
Collagen is proteinaceous in nature and possesses peptide bonds, so (b) matches with (iv) in column II.
Chitin is a homopolymer present in the cell wall of fungi and exoskeleton of arthropods, so, (c) matches with (iii) in column II.
Abrin and Ricin are toxins, secondary metabolites, so (d) in column I matches with (i) in column II.

Meiotic division of secondary oocyte is completed after the entry of sperm in secondary oocyte which lead to the formation of a large ovum and a tiny IInd polar body.

• Robert May estimated global species diversity at about 7 million.
• Although some extreme estimates range from 20 to 50 million.

The first phase of translation involves activation of amino acid in the presence of ATP and linked to their cognate tRNA – a process commonly called as charging of tRNA or aminoacylation of tRNA.

The largely tropical Amazonian rain forest in South America has the greatest biodiversity on earth.

The correct option is : (The functional insulin has A and B chains linked together by hydrogen bonds) because functional insulin has A and B chains linked together by disulphide bridges.

All features are related to monocotyledonous stems.

• Cyclostomes have an elongated body bearing 6-15 pairs of gill slits for respiration
• Air bladder is present in bony fishes belonging to class Osteichthyes which regulates buoyancy
• Trygon, a cartilaginous fish, possesses poison sting
• Heterocercal caudal fin is present in members of class Chondrichthyes

In 1953, S.L. Miller, an American scientist created electric discharge in a closed flask containing CH₄, H₂, NH₃ and water vapor at 800°C.

Embryological support for evolution was disapproved by Karl Ernst von Baer, he noted that embryos never pass through the adult stages of other animals during embryonic development.

• Root pressure is positive hydrostatic pressure.
• It develops in tracheary element at night and in early morning.

A wide variety of chemical substances that we extract from plants on a commercial scale (nicotine, caffeine, quinine, strychnine, opium, etc) are produced by them (plants) as defences against grazers and browsers.

In photorespiration, O2 binds to RubisCo. As a result RuBP instead to being converted to 2 molecules of PGA bind with O2 to form one molecule each of phosphoglycerate (3 carbon compound) and phosphoglycolate ( 2 carbon compound).

Bt cotton is resistant to cotton bollworm (Insect pest). cry I Ac and cry II Ab genes have been introduced in cotton to protect it from cotton bollworm. This makes Bt cotton as biopesticide.

The correct option is (b), (c) and (d)  because :
• Herbicide resistant weeds, drug resistant eukaryotes and man-created breeds of  domesticated animals like dogs are examples of evolution by anthropogenic action.
• Darwin’s Finches of Galapagos islands are example of natural selection, adaptive radiation and founder’s effect.

Active immunity is slow and takes time to give its full effective response in comparison to passive immunity where pre-formed antibodies are administered.