NEET-UG 2009 Question Paper Solutions

Let v be the relative velocity of scooter w.r.t. bus.

v = vₛ − v_B

1000/100 = 10 ms⁻¹

v_B = 10 ms⁻¹

∴ vₛ = v + v_B

= 10 + 10 = 20 ms⁻¹

∴ Velocity of scooter = 20 ms⁻¹

𝐅⃗ = 6î − 8ĵ + 10k̂

|𝐅⃗| = √(6² + (−8)² + 10²) = √(36 + 64 + 100) = 10√2 N

(∵ F = √(Fₓ² + Fᵧ² + F𝓏²))

Given, a = 1 ms⁻²

∴ F = ma

⇒ m = F/a

⇒ m = 10√2/1 = 10√2 kg

Net force,

F = T − mg

ma = T − mg

2000a = 28000 − 20000 = 8000

a = 8000/2000 = 4 ms⁻² ↑

m = mass per unit length

∴ Mass flowing per second = mv

Rate of K.E. = ½(mv)v² = ½mv³

When the body is thrown upwards, its K.E. is converted into P.E.

The loss of energy due to air friction is the difference of K.E. and P.E.

½mv² − mgh

= ½ × 1 × 400 − 1 × 18 × 10

= 200 − 180

= 20 J

Momentum of first part

⇒ 1 × 12 = 12

Momentum of second part

⇒ 2 × 8 = 16

Resultant momentum,

= √((12)² + (16)²) = 20

Then M₁ be the mass of third part M · 4 = 20

M = 20/4 = 5 kg

The position vector of the centre of mass of two particle system is given by

𝐑⃗ cm = (m₁ 𝐫⃗₁ + m₂ 𝐫⃗₂)/(m₁ + m₂)

= 1/4 [−8î − 4ĵ + 4k̂]

= −2î − ĵ + k̂

In absence of external torque, L = Iω = constant

I₁ω₁ = I₂ω₂,

I₁ = MR²,

I₂ = MR² + 2mR²

(Moment of inertia of a thin circular ring about an axis vertical to its plane = MR²)

∴ ω₂ = (I₁/I₂)ω

= (M/(M + 2m))ω

τ vector = 𝐫⃗ × 𝐅⃗

𝐫⃗ · τ vector = 0

𝐅⃗ · τ vector = 0

Since, τ vector is perpendicular to the plane of 𝐫⃗ and 𝐅⃗, hence the dot product of τ vector with 𝐫⃗ and 𝐅⃗ is zero.

Moment of inertia of a thin rod of length l about an axis passing through centre and perpendicular to the rod

= (1/12)Ml²

Thus moment of inertia of the frame,

Ml²/12 + Ml²/4 = (4Ml²)/12 = Ml²/3

Total M.I. = 4 × Ml²/3

= 4Ml²/3

According to Kepler's law, the areal velocity of a planet around the sun always remains constant.

SCD : A₁ – t₁ (areal velocity constant)

SAB : A₂ – t₂

A₁/t₁ = A₂/t₂

t₁ = t₂ × A₁/A₂

(given A₁ = 2A₂)

= t₂ × 2A₂/A₂

∴ t₁ = 2t₂

dQ/dt = kA(T₁ − T₂)/L

[(T₁ − T₂) is the temperature difference]

According to Stefan's law

E = σT⁴

T₁ = 500 K

T₂ = 1000 K

E₂/E₁ = (T₂/T₁)⁴ = (1000/500)⁴ = 16

∴ E₂ = 16 × 7 = 112 cal/cm²s

According to first law of thermodynamics

Q = ΔU + W

ΔU = Q − W

= 2 × 4.2 × 1000 − 500

= 8400 − 500

= 7900 J

In an isochoric process volume remains constant whereas pressure remains constant in isobaric process.

acceleration,

a = −kX,

where,

X = x + a.

In simple harmonic motion acceleration is directly proportional to the displacement from the mean position. Also the acceleration is in the opposite direction of displacement.

Speed,

v = ω√(a² − x²), x = a/2

∴ v = ω√(a² − a²/4)

= ω√(3a²/4)

= (2π/T) × (a√3/2)

= πa√3/T

Restoring force,

f' = −kx

where x is the extension produced in the spring.

Weight of the mass acting downward = Mg.

In equilibrium

kx = Mg

or

x = Mg/k

A = 2 cm,

ω/k = 128 ms⁻¹,

5λ = 4,

λ = 4/5 m

y = A sin(kx − ωt),

k = 2π/λ

⇒ (2π × 5)/4

= 31.4/4

= 7.85

y = 0.02 m sin(7.85x − 1005t)

ω = 128 × 7.85

= 1005

The frequency of vibration of a string is given by,

f = 1/(2l) √(T/m)

where m is mass per unit length.

f₁ = 1/(2l₁) √(T/m), f₂ = 1/(2l₂) √(T/m)

f₂ − f₁ = ½ √(T/m) × (l₁ − l₂)/(l₁l₂)

√(T/m) = √(20/10⁻³) = √2 × 10² = 1.414 × 100

= 141.4

(l₁ − l₂)/(l₁l₂) = ((51.6 − 49.1) × 10²)/(51.6 × 49.1)

= (2.5 × 10²)/(50 × 50)

= 1/10

∴ f₂ − f₁ = ½ × 141.4 × 1/10 = 7 beats

From the given condition

f′ is the apparent frequency received by an observer at the hill. f″ is the frequency of reflected sound as heard by driver.

f′ = v/(v − 30) f

and

f″ = (v + 30)/v × f′

⇒ (v + 30)/(v − 30) f

= (360/300) × 600

= 720 Hz

Energy = 2 eV

⇒ eV₀ = 2 eV

⇒ V₀ = 2 volt

E = V₀/d

= 2/(4 × 10⁻⁸)

= 0.5 × 10⁸

= 5 × 10⁷ Vm⁻¹

.

The electric field at a point is equal to negative of potential gradient at that point.

𝐄⃗ = −∂V/∂r

= −[ (∂V/∂x)î + (∂V/∂y)ĵ + (∂V/∂z)k̂ ]

= [(2xy + z³)î + ĵx² + k̂3xz²]

In series combination of capacitors

V_eff = V + V + V = 3V

1/C_eff = 1/C + 1/C + 1/C

⇒ C_eff = C/3

Thus, the capacitance and breakdown voltage of the combination will be C/3 and 3V.

Length of wire = 2πr = 2π(0.1) = 0.2π m

Resistance of complete circle/wire = 12 × 0.2π = 2.4π Ω

∴ Resistance of each semi-circle = 1.2π Ω

Hence, equivalent resistance,

R Subscript (AB) = 1.2π/2 = 0.6π Ω

Applying Kirchhoff’s rule in loop abcfa

ε₁ − (i₁ + i₂)R − i₁r₁ = 0.

The terminal potential difference of a cell is given by

V + Ir = E

or

V = V_A − V_B

V = E − Ir

⇒ dV/dI = −r

Also for, i = 0 then V = E

∴ slope = −r, intercept = E

The magnetic force acting on the charged particle is given by

𝐅⃗ = q(𝐯⃗ × 𝐁⃗)

= (−2 × 10⁻⁶)[{(2î + 3ĵ) × 10⁶} × (2ĵ)]

= −4(2k̂) = −8k̂

∴ Force is of 8 N along negative z-axis.

The time period of the charged particle is given by,

T = 2πm/qB

Thus, time period is independent of both v and R.

G = 60Ω, I_g = 1.0 A, I = 5 A.

Let S be the shunt resistance connected in parallel to galvanometer.

I_g G = (I − I₉)S

S = I_g G/(I − I_g)

= (1/(5 − 1)) × 60

= 15Ω

Thus by putting 15Ω in parallel, the galvanometer can be converted into an ammeter.

Work done

= MB(cos θ₁ − cos θ₂)

= MB(cos 0° − cos 60°)

= MB(1 − 1/2)

= (2 × 10⁴ × 6 × 10⁻⁴)/2

= 6 J

Diamagnetic substances do not have any unpaired electron. And they are magnetised in direction opposite to that of magnetic field. Hence, when they are brought to north or south pole of a bar magnet, they are repelled by poles.

The induced emf will remain constant only in the case of rectangular and square loops. In case of the circular and the elliptical loops, the rate of change of area of the loops during their passage out of the field is not constant, hence induced emf will not remain constant for them.

Induced emf in the loop is given by

e = −B · dA/dt

where A is the area of the loop.

e = −B · d/dt (πr²)

= −Bπ2r · dr/dt

r = 2 cm = 2 × 10⁻² m

dr = 2 mm = 2 × 10⁻³ m

dt = 1 s

e = −0.04 × 3.14 × 2 × 2 × 10⁻² × (2 × 10⁻³)/1 V

= 0.32π × 10⁻⁵ V

= 3.2π × 10⁻⁶ V

= 3.2π μV

Power dissipated in series LCR;

P = I²R

= ε²/(Z²) R

= ε²R/[R² + (ωL − 1/ωC)²]

Comparing with the equation of wave.

Eᵧ = E₀ cos(ωt − kx)

ω = 2πf = 2π × 10⁶

∴ f = 10⁶ Hz

2π/λ = k = π × 10⁻² m⁻¹

∴ λ = 200 m

The number of photoelectrons emitted is proportional to the intensity of incident light.
Saturation current ∝ intensity.

Retarding potential depends on the frequency of incident radiation but is independent of intensity.

λ = 667 × 10⁻⁹ m, P = 9 × 10⁻³ W

P = Nhc/λ, N = No. of photons emitted/sec.

N = (9 × 10⁻³ × 667 × 10⁻⁹)/(6.6 × 10⁻³⁴ × 3 × 10⁸)

= (9 × 6.67 × 10⁻¹⁰)/(3 × 6.6 × 10⁻²⁶)

= 3 × 10¹⁶ /sec

The kinetic energy of the projectile is given by

½mv² = Ze(2e)/(4πɛ₀r₀)

= Z₁Z₂/(4πɛ₀r₀)

Thus energy of the projectile is directly proportional to Z₁Z₂.

n(n − 1)/2 = 6

n² − n − 12 = 0

(n − 4)(n + 3) = 0

or n = 4

A radioactive substance when emits one alpha particle (⁴₂He), its mass number reduces by 4 and charge no. reduces by 2 and after emission of two β-particles its charge no. increase by 2 thus the charge no. i.e. atomic number remains the same.

.

λₘₐₓ = hc/E

= (6.6 × 10⁻³⁴ × 3 × 10⁸)/(2.5 × 1.6 × 10⁻¹⁹)

= 5000 Å

The wavelength detected by photodiode should be less than λₘₐₓ. Hence it can detect a signal of wavelength 4000 Å.

d = (√3/2)a

3.7 = (√3/2)a

a = (2 × 3.7)/√3

= 4.3 Å

ΔI Subscript (E) = ΔI Subscript (B) + ΔI Subscript (C)

β = ΔI Subscript (C)/ΔI Subscript (B)

ΔI Subscript (C) = (10 − 5) × 10⁻³

= 5 × 10⁻³ A

ΔI Subscript (B) = (200 − 100) × 10⁻⁶

= 100 × 10⁻⁶ A

β = (5 × 10⁻³)/(100 × 10⁻⁶)

= (5/100) × 1000

= 50

the correct one is (ii), (iv) and (iii).

The drugs which are used to reduce anxiety and for the treatment of mental diseases, are called tranquilizers. These drugs are also known as psychotherapeutic drugs. Luminal, Seconal and Equanil are two commonly used tranquilizers.

No. of milli equivalent of HCl

= 20 × 0.05 = 1.0

No. of milli equivalent of Ba(OH)₂

= 30 × 0.1 × 2 = 6.0

After neutralization, no. of milli equivalents in 50 mL of solution

= (6 − 1) = 5

Total volume of the solution = 20 + 30 = 50 mL

∴ No. of equivalent of OH⁻ in 50 mL is

[OH⁻] = (5 × 1000/50) × 10⁻³ = 0.1 M

H₂ + ½O₂ ⟶ H₂O

10 g 64 g

(5 mol) (2 mol)

In this reaction oxygen is the limiting agent. Hence, amount of H₂O produced depends on the amount of O₂ taken.

∵ 0.5 mol of O₂ gives H₂O = 1 mol

∴ 2 mol of O₂ gives H₂O = 4 mol

Neoprene is a polymer of chloroprene.

Thyroxine is the only hormone among the given choices that contains iodine. Its structure is as follows:

The DNA sequence that codes for a specific protein is called a Gene and thus every protein in a cell has a corresponding gene.

Nitric acid acts as a base by accepting a proton.

Secondary amine with (NaNO₂ + HCl) gives a nitroso product.

This reaction is an example of Hell–Volhard–Zelinsky reaction. In this reaction acids containing α–H on treatment with X₂/P give di-halo substituted acid.

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1,2–Diols, when treated with an aqueous solution of periodic acid, give aldehyde or ketones.

.

.

.

In nucleophilic substitution, a nucleophile provides an electron pair to the substrate and the leaving group departs with an electron pair.

Since Cr³⁺ in the complex has unpaired electrons in the d orbital, hence will be coloured.

Ti = [Ar]3d²4s²; Ti⁴⁺ = 3d⁰

Cr = [Ar]3d⁵4s¹;  Cr³⁺ = 3d³

Zn = [Ar]3d¹⁰4s²;  Zn²⁺ = 3d¹⁰

Sc = [Ar]3d¹4s²;  Sc³⁺ = 3d⁰

The octahedral coordination compounds of the type MA₃B₃ exhibit fac-mer isomerism.

In TiF₆²⁻ – Ti is in +4 O.S.; 3d⁰ – colourless

In CoF₆³⁻ – Co is in +3 O.S.; 3d⁶ – coloured

In Cu₂Cl₂ – Cu is in +1 O.S.; 3d¹⁰ – colourless

In NiCl₄²⁻ – Ni is in +2 O.S.; 3d⁸ – coloured

Mn – 3d⁵4s²

The no. of various oxidation states possible are +2, +3, +4, (+5), +6, +7.

Standard reduction potential of halogens are positive and decreases from fluorine to iodine. Therefore, halogens act as strong oxidising agent and their oxidising power decreases from fluorine to iodine.

MI > MBr > MCl > MF.

As the size of the anion decreases covalency decreases.

When concentration of A is doubled, rate is doubled. Hence order with respect to A is one.

When concentrations of both A and B are doubled, rate increases by 8 times hence order with respect to B is 2.

∴ rate = k[A]¹[B]²

For a first order reaction

t₁/₂ = 0.693/k

k = 0.693/1386

= 0.5 × 10⁻³ s⁻¹

Rate of disappearance of Br⁻ = Rate of appearance of Br₂

⇒ −1/5 d[Br⁻]/dt = 1/3 d[Br₂]/dt

⇒ d[Br₂]/dt = −3/5 d[Br⁻]/dt

Rate of disappearance of H₂ = Rate of formation of NH₃

⇒ −1/3 d[H₂]/dt = 1/2 d[NH₃]/dt

⇒ −d[H₂]/dt = 3/2 d[NH₃]/dt

= 3/2 × 2 × 10⁻⁴

= 3 × 10⁻⁴ mol L⁻¹ s⁻¹

Cu²⁺ + 2e⁻ ⟶ Cu; ΔG° = −nE°F

= −2 × F × 0.337 = −0.674F  ...(i)

Cu⁺ ⟶ Cu²⁺ + e⁻; ΔG° = −nE°F

= −1 × F × (−0.153) = 0.153F  ...(ii)

On adding eqn (i) & (ii)

Cu⁺ + e⁻ ⟶ Cu;

ΔG° = −0.521F = −nE°F;

Here n = 1

∴ E° = +0.52 V

As Q = i × t

∴ Q = 4.0 × 10⁴ × 6 × 60 × 60 C

= 8.64 × 10⁸ C

Now since 96500 C liberates 9 g of Al

8.64 × 10⁸ C liberates

= (9/96500) × 8.64 × 10⁸ g Al

= 8.1 × 10⁴ g of Al

Degree of dissociation,

α = Λ/Λ∞ = 8.0/400 = 2 × 10⁻²

Kₐ = Cα²/(1 − α)

≈ Cα²

= 1/32 × (2 × 10⁻²)²

= 1.25 × 10⁻⁵

ΔT_f = 0 − (−0.00732) = 0.00732

ΔT_f = i × K_f × m

i = ΔT_f /(K_f × m)

= 0.00732/(1.86 × 0.002)

= 2

Since lithium metal crystallises in a body centred cubic crystal

r = a√3/4

= (351 × 1.732)/4

= 151.98 pm

Since Cu metal crystallises in a face centred cubic lattice

∴ r = a/(2√2)

r = 361/(2√2) = 127.6 ≈ 128 pm

Alkenes with double bonds cannot undergo free rotation and can have different geometrical shapes with two different groups on each end of the double bond.

So the IUPAC name of the compound is 1-butene-3-yne.

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Hydrolysis of substituted chlorosilanes yield corresponding silanols which undergo polymerisation.

NaOH is a strong alkali. It combines with acidic and amphoteric oxides to form salts. Since CaO is a basic oxide hence does not react with NaOH.

PO₄³⁻ = x + 4(−2) = −3; x − 8 = −3; x = +5

SO₄²⁻ = x + 4(−2) = −2; x − 8 = −2; x = +6

Cr₂O₇²⁻ = 2x + 7(−2) = −2; 2x − 14 = −2; 2x = 12; x = +6

Ammonium chloride is a salt of weak base and strong acid. In this case, hydrolysis constant, Kₕ can be calculated as

Kₕ = K_w /K_b

= (1 × 10⁻¹⁴)/(1.77 × 10⁻⁵)

= 5.65 × 10⁻¹⁰

(CH₃)₃B is electron deficient, thus behave as a Lewis acid.

Given,

CH₃COOH ⇌ CH₃COO⁻ + H⁺;

Kₐ₁ = 1.5 × 10⁻⁵  ...(i)

HCN ⇌ H⁺ + CN⁻;

Kₐ₂ = 4.5 × 10⁻¹⁰

or

H⁺ + CN⁻ ⇌ HCN;

K′ₐ₂ = 1/Kₐ₂

= 1/(4.5 × 10⁻¹⁰)  ...(ii)

∴ From (i) and (ii), we find that the equilibrium constant (Kₐ) for the reaction,

CN⁻ + CH₃COOH ⇌ CH₃COO⁻ + HCN,

Kₐ = Kₐ₁ × K′ₐ₂

= (1.5 × 10⁻⁵)/(4.5 × 10⁻¹⁰)

= (1/3) × 10⁵

= 3.33 × 10⁴

ΔG = ΔH − TΔS

At equilibrium, ΔG = 0

⇒ 0 = (170 × 10³ J) − T(170 JK⁻¹)

⇒ T = 1000 K

For spontaneity, ΔG is −ve, which is possible only if T > 1000 K.

Enthalpy of reaction

= ΣB.E. Subscript (Reactant) − ΣB.E. Subscript (Product)

= [B.E. Subscript (C=C) + 4B.E. Subscript (C−H) + B.E. Subscript (H−H)]

− [B.E. Subscript (C−C) + 6B.E. Subscript (C−H)]

= [606.1 + (4 × 410.5) + 431.37] − [336.49 + (6 × 410.5)]

= −120.0 kJ mol⁻¹

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We find that in the given molecules hybridisation is

BF₃ → sp²

NO₂⁻ → sp²

NH₂⁻ → sp³

H₂O → sp³

Due to intermolecular hydrogen bonding in methanol, it exist as associated molecule.

The stability of +1 oxidation state increases from aluminium to thallium i.e.

Al < Ga < In < Tl

The smaller the atomic size, larger is the value of ionisation potential. Further the atoms having half filled or fully filled orbitals are comparatively more stable, hence more energy is required to remove the electron from such atoms.

The number of subshell is (2l + 1). The maximum number of electrons in the subshell is

2(2l + 1) = (4l + 2)

m = 2l + 1, thus for l = 2, m = 5, hence values of m will be −2, −1, 0, +1, +2.

Therefore for l = 2, m cannot have the value −3.

K.E per atom

= [(4.4 × 10⁻¹⁹) − (4.0 × 10⁻¹⁹)] / 2

= (0.4 × 10⁻¹⁹) / 2

= 2.0 × 10⁻²⁰ J

Late blight is caused by the fungus Phytophthora infestans. Late blight appears on potato or tomato leaves as pale green, water-soaked spots, often beginning at leaf tips or edges. The circular or irregular leaf lesions are often surrounded by a pale yellowish-green border that merges with healthy tissue. Lesions enlarge rapidly and turn dark brown to purplish-black.

Mannitol is a food stored in Fucus. Fucus is a genus of brown alga in the clas Phaeophyceae to be found in the intertidal zones of rocky seashores almost everywhere in the world. Primary chemical constituents of this plant include mucilage, algin, mannitol, beta-carotene, zeaxanthin, iodine, bromine, potassium, volatile oils, and many other minerals.

Pinus plant is monoecious i.e. both male and female cone are present in same plant but on different branches. Pinus, with over 100 species, is the largest genus of conifers and the most widespread genus of trees in the Northern Hemisphere.

Equisetum is a vascular cryptogam. Equisetum is the only living genus in the Equisetaceae, a family of vascular plants that reproduce by spores rather than seeds. They are commonly known as horse tails.

Ustilago has a haplontic life cycle. This is a simplest and most primitive type of life cycle. The other pattern of life-cycle have originated from this type. This type is found in all Chlorophyceae. In such cases, the somatic phase (plant) is haploid (gametophyte) while the diploid phase (sporophyte) is represented by zygote. During germination the zygote (2n) divides meiotically producing haploid (n) zoospores, which develop into individual plant. Here, the unicellular or filamentous gametophyte (n) alternates with one-celled zygote or sporophyte (2n).

Aschelminthes is bilaterally symmetrical and triploblastic. These are mostly aquatic, free living or parasitic. Their body is three layered which is ectoderm, mesoderm and endoderm.

Lampreys and hagfishes are unusual, jawless fish that comprise the order Cyclostomata, so named because of the circular shape of the mouth. The brains of lampreys and hagfishes differ a lot, but they also show a large number of similarities, as do all craniate brains.

In flowering plants, placentation occurs where the ovules are attached inside the ovary. An example of axile placentation is citrus. In this type of placentation the ovary is sectioned by radial spokes with placentas in separate locules.

The given floral formula is of tobacco. It belong to the family Solanaceae. The flower is actinomorphic, bisexual and has superior ovary. Soyabean and sunhemp have monocarpellary pistil and tulip has trimerous flower and perianth.

Reduction in vascular tissue, mechanical tissue and cuticle is characteristic of hydrophytes.

Palisade parenchyma is absent in leaves of sorghum. It is a leaf tissue composed of columnar cells containing numerous chloroplasts in which the long axis of each cell is perpendicular to the leaf surface. The palisade parenchyma is usually directly beneath the epidermis of the upper surface of the leaf.

Anatomically fairly old dicotyledonous root is distinguished from the dicotyledonous stem by position of protoxylem. In dicot root the protoxylem is located near the periphery of the vascular cylinder while in dicot stem the protoxylem is located near the centre of vascular bundle i.e. the xylem is endarch.

The annular and spirally thickened conducting elements generally develop in the protoxylem when the root or stem is maturing.

In barley stem, vascular bundles are closed and scattered. They are open only for a hours in the day time and never open at night. e.g. Cereals.

Ciliated epithelium has simple columnar epithelial cells, but in addition, they possess fine hair-like outgrowths, cilia, on their free surfaces. These cilia are capable of rapid, rhythmic, wavelike beatings in a certain direction. This movement of the cilia in a certain direction causes the mucus, which is secreted by the goblet cells, to move (flow or stream) in that direction.

The cell junctions known as tight, adhering and gap junctions are found in epithelial tissue. Epithelial tissue covers the whole surface of the body. It is made up of cells closely packed and ranged in one or more layers. This tissue is specialised to form the covering or lining of all internal and external body surfaces.

The kind of tissue that forms the supportive structure in our pinna (external ears) is also found in tip of the nose. External pinna is made up of elastic cartilage. It is the passage towards middle ear.

If a live earthworm is pricked with a needle on its outer surface without damaging its gut, the fluid that comes out is coelomic fluid because coelomic fluid lies between body wall and alimentary canal.

In Pheretima two pairs of testes sacs are situated in the 10th and 11th segments. Each testes sac of the 10th segment encloses a testes and a seminal funnel. Each testes sac of the 11th segment encloses a testes, a seminal vesicle and a seminal funnel.

Plasmodesmata are connections between adjacent cells. Plasmodesmata are narrow channels that act as intercellular cytoplasmic bridges to facilitate communication and transport of materials between plant cells.

The cytoskeleton is made up of three kinds of protein filaments: actin filaments (also called microfilaments), intermediate filaments and microtubules whose major constituents are actin and tubulin respectively.

Stroma in the chloroplasts of higher plant contains light independent reaction enzymes. Within the stroma are stacks of thylakoids, the sub-organelles which are the site of photosynthesis.

Middle lamella is mainly composed of calcium pectate. Calcium is deposited in plant cell walls during their formation—it is required for the stability and function of cell membranes and acts as a type of “cementing agent” in the cell walls in the form of calcium pectate.

In schematic break-up of the phases/ stages of cell cycle, D synthetic phase is the correct indication of the stage/phase in the cell cycle.

Synapsis is the pairing of two homologous chromosomes that occurs during prophase I (zygotene stage) of meiosis. The two chromosomes move together and pair corresponding along their lengths as they lie side to side. The resulting structure is called a bivalent.

Guard cells help in transpiration. Transpiration is the evaporation of water from the aerial parts of plants, especially leaves but also stems, flowers and roots. Stomatal opening allows the diffusion of carbon dioxide and oxygen during photosynthesis.

Manganese is essential for many plant functions.

Some of them are:

• The assimilation of carbon dioxide in photosynthesis.

• It is involved in the Hill Reaction where water is split during photosynthesis.

• It aids in the synthesis of chlorophyll and in nitrate assimilation.

• Manganese activates fat forming enzymes.

• It functions in the formation of riboflavin, ascorbic acid, and carotene.

• It functions in electron transport during photosynthesis.

Frankia is a symbiotic nitrogen fixer in root nodules of several non-legume plants like Casuarina and Alnus.

Oxygenic photosynthesis occurs in Oscillatoria. It is a genus of filamentous cyanobacteria which is named for the oscillation in its movement.

Cyclic photophosphorylation results in the formation of ATP. This process is called photophosphorylation, which occurs in two different ways. Adenosine triphosphate (ATP) is considered by biologists to be the energy currency of life.

All energy-releasing pathways whether aerobic (requiring oxygen) or anaerobic (not requiring oxygen) begin with a pathway called glycolysis, which occurs in the cytoplasm (cytosol). Aerobic respiratory pathway is thus appropriately termed as amphibolic.

NAA is a synthetic auxin. Some of the most widely used weed killers are synthetic auxins. Synthetic auxin analogs include 1–naphthaleneacetic acid (NAA), 2,4–dichlorophenoxy acetic acid (2,4-D) and 2,4,5-trichlorophenoxy acetic acid (2,4,5-T).

Abscisic acid (ABA), also known as abscisin II and dormin, is a plant hormone. It functions in many plant developmental processes, including bud dormancy. Abscisic acid is a derivative of carotenoids. It was called “abscisin II” originally because it was thought to play a major role in abscission of fruits. At about the same time another group was calling it “dormin” because they thought it had a major role in bud dormancy. The name abscisic acid (ABA) was coined as a compromise between the two groups.

Synapsis is the pairing of two homologous chromosomes that occurs during prophase I (zygotene stage) of meiosis. The two chromosomes move together and pair corresponding along their lengths as they lie side to side. The resulting structure is called a bivalent.

Young infant may be feeding entirely on mother’s milk which is white in colour but the stools which the infant passes out is quite yellowish because of the bile pigments passed through bile juice. Bile pigments are any of several coloured compounds derived from porphyrin that are found in bile; principally bilirubin and biliverdin. Bile pigment is produced regularly when old red blood cells are broken down, mainly by the spleen. In some blood-disorders where the red cells are destroyed, more bile pigment is produced.

Fructose and amino acids are absorbed through intestinal mucosa with the help of carrier ions like Na⁺. Carbohydrates are absorbed as monosaccharides (simple sugars such as glucose, fructose, and galactose that cannot be further broken down by hydrolysis) or as disaccharides (such as sucrose, lactose, maltose, and dextrin that can be hydrolyzed to two monosaccharides). These simpler molecules, however, must be obtained by the breaking down of polysaccharides, complex carbohydrates that contain many monosaccharides. Chief among these is amylase, a starch that accounts for 20 percent of dietary carbohydrate.

Fat and cellulose is the pair of food components in human that reaches the stomach totally undigested.

If breast feeding is replaced by less nutritive food low in proteins and calories; the infants below the age of one year are likely to suffer from Marasmus. It is a form of malnutrition that occurs when there is not enough protein in the diet. This disease is more common in very poor countries. It often occurs during a drought or other natural calamities, or during political unrest. These conditions are responsible for a lack of food, which leads to malnutrition.

The ABO blood group system is the most important blood type system (or blood group system) in human blood transfusion. It is named ABO and not ABC, because blood group O (or blood group zero in some countries) individuals do not have either A or B antigens on the surface of their RBCs, but their blood serum contains IgM anti-A antibodies and anti-B antibodies against the A and B blood group antigens. Therefore, a group O individual can receive blood only from a group O individual, but can donate blood to individuals of any ABO blood group (i.e. A, B, O or AB).

Lymph is a mobile connective tissue comprising lymph plasma and lymph corpuscles. Its composition is just like blood plasma except that it lacks RBCs and large plasma proteins.

Red blood cells are the most common type of blood cell and delivering oxygen to the body tissues via the blood. There is no DNA in mature RBC. The reticulocyte which is the immediate precursor of the mature RBC evolves into mature RBC within 24 hours of release into the peripheral circulation.

Globulins contained in human blood plasma are primarily involved in defence mechanism of body. Globulin is one of the two types of serum proteins, the other being albumin. Globulins can be divided into three fractions based on their electrophoretic mobility.

In a standard ECG, the P-wave is a small upward wave that indicates the depolarisation of the atria. This is caused by the activation of SA node.

Uric acid is the chief nitrogenous component of the excretory product of cockroach. Animals which live in dry conditions have to conserve water in their bodies. Therefore, they synthesise crystals of uric acid from ammonia. Uric acid crystals are non-toxic and can be retained in the body for a considerable time. Uricotelic animals include insects, reptiles and birds.

Sensory stretch receptors are responsible for the stretch reflex. If these are removed then autonomic nervous system control will not be there and micturition will continue. Micturition is the expulsion of urine from the urinary bladder.

The pelvic girdle is formed by two innominate bones consists of three separate bones ilium, ischium and the pubis.

Elbow joint is an example of hinge joint. The elbow is a hinge joint; it can open and close like a door. Hinge joint is a form of diarthrosis (freely movable joint) that allows angular movement in one plane only, increasing or decreasing the angle between the bones e.g. elbow joint, knee joint etc.

Hypothalamus part of human brain is concerned with the regulation of body temperature. The hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions. The hypothalamus is small cone-shaped structure, projects downward, ending in the pituitary.

Alzheimer disease in humans is associated with the deficiency of acetylcholine. Acetylcholine is the neurotransmitter produced by neurons referred to as cholinergic neurons. Acetylcholine plays a role in skeletal muscle movement, as well as in the regulation of smooth muscle and cardiac muscle. Acetylcholine is synthesised from choline and acetyl coenzyme-A through the action of the enzyme choline acetyltransferase and becomes packaged into membrane-bound vesicles.

Myxoedema is caused by deficiency of thyroid hormone or thyroxine in adults. It is characterised by increase in body weight, puffy appearance, low metabolic rate, and tendency to retain water in tissues.

Vegetative propagation in mint occurs through sucker. Vegetative reproduction is a type of asexual reproduction for plants, and is also called vegetative propagation, vegetative multiplication, or vegetative cloning. It is a process by which new plant “individuals” arise and are obtained without production of seeds or spores.

The fig (*Syconus*) is an aggregate fruit, consisting of numerous seed-like pericarps enclosed within a hollow, fleshy receptacle where the flowers were attached. This fruit developed from hypanthodium inflorescence.

Cotyledons and testa respectively are edible parts in groundnut and pomegranate. A cotyledon is a significant part of the embryo within the seed of a plant. Upon germination, the cotyledon may become the embryonic first leaves of a seedling. Testa is often thick or hard outer coat of a seed.

An example of a seed with endosperm, perisperm, and caruncle is castor. Castor seed is the source of castor oil, which has a wide variety of uses. The seeds contain between 40% and 60% oil that is rich in triglycerides.

Human seminal plasma is a complex mixture of proteins, glycoproteins, peptides, glycolipids, and prostaglandins secreted by organs of the male reproductive tract. The components of this fluid have been implicated in the suppression of immune response, agonistic effects on sperm-egg binding, and promotion of successful implantation of the human embryo. Seminal plasma in humans is rich in fructose, calcium and certain enzymes.

The human male reproductive system consists of a number of sex organs that are a part of the human reproductive process. In diagram of human, the point indicated by A, B, C, D are vas deferens, seminal vesicle, prostate and bulbourethral gland.

The corpus luteum is essential for establishing and maintaining pregnancy in females. In the ovary, the corpus luteum secretes estrogens and progesterone, which are steroid hormones responsible for the thickening of the endometrium and its development and maintenance, respectively.

Fertilization of ovum is the most likely root cause when menstruation is not taking place in regularly cycling human female. In order for fertilization to occur, one of these sperm must attach itself to the ovum and penetrate its outer surface. The fertilized ovum will then continue travelling down the fallopian tube, taking several days until it reaches the uterus. When it arrives, it attaches itself to the lining of the uterus and continues to grow. If the ovum is not fertilized it will die and the progesterone and estrogen hormone levels will drop. Without these hormones the prepared uterus lining breaks up and is released through the vagina. This is known as a “period”.

Foetal ejection reflex in human female is induced by fully developed foetus and placenta. When a woman is in a lithotomy or semi-sitting position, The Foetal Ejection Reflex is impaired and the increased vascularity caused by the sacrum's inability to move as the baby descends can be intolerable.

A change in the amount of yolk and its distribution in the egg will affect pattern of cleavage. The pattern of cleavage is influenced by the amount of yolk in the egg. In eggs with less yolk, cleavages are equal, and the resulting blastomeres are cells of similar size. If the yolk is localized, such as in frog eggs, then cleavages are unequal; the cells derived from the yolky region (the vegetal pole) are larger than those derived from the region without yolk (the animal pole).

The chart shows the inheritance of a condition like phenylketonuria as an autosomal recessive trait. Parents need to be heterozygous as two of their children are known to be sufferer of the disease. It cannot be recessive sex linked inheritance because then the male parent would also be sufferer.

By introducing bone marrow cells producing ADA into cells at early embryonic stages, the genetic defect adenosine deaminase (ADA) deficiency may be cured permanently. It is due to mutation.

Sickle cell anaemia is caused by a change in a single base pair of DNA. Sickle cell anaemia is controlled by a single pair of alleles, Hbᴬ and Hbˢ and the genotype HbˢHbˢ show the diseased phenotype. Sickle cell disease or sickle cell anaemia (or drepanocytosis), is a life-long blood disorder characterised by red blood cells that assume an abnormal, rigid, sickle shape. Sickling decreases the cells flexibility and results in a risk of various complications.

Baldness is a sex influenced trait. The dominance of alleles may differ in heterozygotes of the two sexes.

A point mutation is a simple change in one base of the gene sequence. This is equivalent to changing one letter in a sentence, such as in this example, where we change the ‘c’ in cat to an ‘h’.

Original: The fat cat ate the wee rat.

Point Mutation: The fat hat ate the wee rat.

Theodor O. Diener discovered the Potato Spindle Tuber Viroid (“PSTVd”), the first viroid ever identified, in 1971. PSTVd is a small, circular RNA molecule. Dr. Diener discovered that the pathogen causing potato spindle tuber disease is not a virus, as previously believed, but a much smaller, free RNA molecule.

The genetic code consists of 64 triplets of nucleotides. These triplets are called codons. With three exceptions, each codon encodes for one of the 20 amino acids used in the synthesis of proteins. That produces some redundancy in the code. Most of the amino acids being encoded by more than one codon. The genetic code can be expressed as either RNA codons or DNA codons.

Splicing is the removal of introns and joining the exons in a defined order in a transcription unit. In molecular biology, splicing is a modification of RNA after transcription, in which introns are removed and exons are joined.

Nirenberg and Matthaei (1961) experimentally proved that a single amino acid is determined by a sequence of three nitrogen bases. The sequence of three nitrogen bases determining a single amino acid is called a triplet code. Nirenberg and Matthaei experiments cracked the DNA and discovered unequivocally that a genetic code is a triplet.

Semiconservative replication of DNA was first demonstrated in Escherichia coli. E. coli is a common type of bacteria that can get into food, like beef and vegetables. The strange thing about these bacteria is that they are not always harmful to you. E. coli normally lives inside your intestines, where it helps your body breakdown and digest the food you eat.

Peripatus is a genus of Onychophora (Velvet worms). It is said to be a living fossil because it has been unchanged for approximately 570 million years. Peripatus is a nocturnal carnivore. Peripatus is a connecting link between Annelida and Arthropoda. It feeds by trapping its prey (mostly small insects) in a white, sticky fluid it ejects from two antennae near its head. The fluid hardens on contact with the air and then the prey becomes immobilized.

In the case of peppered moth (Biston betularia) the black coloured form became dominant over the light coloured form in England during industrial revolution. This is an example of natural selection. This group is about species that gain protection from predators due to selection caused by nature.

Tetanus toxoid is a vaccine consisting of growth products of Clostridium tetani treated with formaldehyde serving as an active immunising agent. Hence it is weakened germs. The first tetanus toxoid (inactivated toxin) was produced in 1924 and was used successfully to prevent tetanus in the armed services during World War II. In the mid-1940s, tetanus vaccine was combined with diphtheria toxoid and inactivated pertussis vaccine to make the combination DTP vaccine for routine childhood immunization.

The letter T in T-lymphocyte refers to thymus. In human anatomy, the thymus is an organ located in the upper anterior portion of the chest cavity just behind the sternum. The thymus gland is a pink-grey organ that lies underneath the top of the breast bone.

The use of anti-histamines and steroids gives a quick relief from headache. Antihistamines are drugs that block the action of histamine (a compound released in allergic inflammatory reactions) at the H₁ receptor sites, responsible for immediate hypersensitivity reactions such as sneezing and itching.

Common Cold, AIDS is a pair of viral diseases. Viruses are a very common type of infectious disease. Viruses are the smallest life-form existing, since they are not even a single cell. It is almost like they are not alive at all. They are small strands of DNA-like cell material. A virus consists mostly of RNA and cannot survive without host cells.

Malignant tumours may exhibit metastasis. Cancer (medical term: malignant neoplasm) is a class of diseases in which a group of cells display uncontrolled growth (division beyond the normal limits), invasion (intrusion on and destruction of adjacent tissues), and sometimes metastasis spread to other locations in the body via lymph or blood.

Xanthomonas campestris is not used as a biopesticide. Xanthomonas campestris is a plant pathogen that causes black rot in cotton plants.

Jatropha is useful for production of bioethanol. Jatropha is a genus of approximately 175 succulent plants, shrubs and trees (some are deciduous, like Jatropha curcas L.), from the family Euphorbiaceae. The hardy Jatropha is resistant to drought and pests, and produces seeds containing 27–40% oil. Currently the oil from Jatropha curcas seeds is used for making biodiesel fuel in Philippines and in Brazil, where it grows naturally and in plantations in the southeast, and the north/northeast Brazil.

Genetic variation present among plant cells during tissue culture is called somaclonal variation. The term somaclonal variation is also used for the genetic variation present in plants regenerated from a single culture. This variation has been used to develop several useful varieties against resistance to diseases and pests, better yield, better quality etc.

Alcohol and nitrogenase pair is wrongly matched. Ethanol produces alcohol.

gene transfer without a vector

Agrobacterium tumefaciens is the causal agent of crown gall disease (the formation of tumours) in over 140 species of dicot. This disease is caused by a DNA plasmid (Ti plasmid) carried by bacterium and transferred to the plant cells. Ti plasmid has widely used in plant engineering as a vector in order to inject gene in host plant to form transgenic plant.

The inactive protoxin gets converted into active form in the insect gut.

The bacterium Bacillus thuringiensis is widely used in contemporary biology as insecticide. Bacillus thuringiensis (also known as Bt) is a Gram-positive, soil dwelling bacterium of the genus Bacillus. Bacillus thuringiensis produces a parasporal insecticidal crystal protein.

Transgenic plants are the ones generated by introducing foreign DNA into a cell and regenerating a plant from that cell.

‘A’ is more recent and shows slight reduction in growth rate.

Volvox → Hydrilla → Pistia → Scirpus → Lantana → Oak

Fish

Wheat

compulsory PUC (Pollution Under Control) certification of petrol driven vehicles which tests for carbon monoxide and hydrocarbons.

Biochemical Oxygen Demand (BOD) in a river water increases when sewage gets mixed with river water. Bio - chemical oxygen demand or biological oxygen demand (BOD) is a chemical procedure for determining how fast biological organisms use up oxygen in a body of water.

It is used in water quality management and assessment, ecology and environmental science.

lipo soluble

The Montreal Protocol

The aim of Montreal protocol was to protect the ozone layer in the stratosphere by decreasing and eventually eliminating the use of ozone depleting substances like CFCs.

forests

Gir

Spermatogonia → spermatocyte → spermatid → sperms

Development of heterospory or formation of two types of spores is important for the development of seed habit. The two types of spores are smaller male ormicrospmesmdl larger female or megaspores. Two types of spores form two. different types of gametophytes, male and female.

Frankia

Genetic diversity is the diversity in the number and types of genes as well as chromosomes present in different species and the variation in the genes and their alleles in the same species. India has more than 50,000 geneficflny diverse varieties of rice and 1000 varieties of mango.