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The bilobed anther can produce 1600 male gametophytes.

Let the original speed of the train be x km/h

∴ (360/x - 360/x + 5) = 48/60

⇒ x² + 5x - 2250 = 0

⇒ (x +50) (x -45) = 0

∴  x = 45

Hence original speed of the train = 45km/h

No, because the two triangles with equal corresponding angles need not be congruent. In such a correspondence, one of them can be an enlarged copy of the other.

Let the four consecutive numbers in AP be (a - 3d), (a - d), (a + d) and (a + 3d)
So, according to the question.
a-3d + a - d + a + d + a + 3d = 32
4a = 32
a = 32/4
a = 8 ......(1)
Now, (a - 3d)(a + 3d)/(a - d)(a + d) = 7/15
15(a² - 9d²) = 7(a² - d²)
15a² - 135d² = 7a² - 7d²
15a² - 7a² = 135d² - 7d² 
8a² = 128d²
Putting the value of a = 8 in above we get.
8(8)² = 128d²
128d² = 512
d² = 512/128
d² = 4
d = 2
So, the four consecutive numbers are 
8 - (3*2)
8 - 6 = 2
8 - 2 = 6
8 + 2 = 10
8 + (3*2)
8 + 6 = 14
Four consecutive numbers are 2, 6, 10 and 14

Subtract 1, 2, 3 from 1251, 9377, 15628 respectively. 

1251 - 1 = 1250, 

9377 - 2 = 9375, 

15628 - 3 = 15625 

Find the HCF of 1250 and 9375 

9375 = 1250 x 7 + 625

1250 = 625 x 2 + 0 

thus 625 is the HCF 

Now, find the HCF of 625 and 15625 

15625 = 625 x 25 + 0 

Thus 625 is the number that divides 1251, 9377 and 15628 leaving the remainders 1, 2 and 3 respective.

Number of cards left in the deck of 52 cards = 52 – 3 = 49

Number of queens in the deck = 3

P (Getting a queen) = 3/49

In 1 hour, minute hand completes one round means makes a circle. Radius of the circle (r ) = 15 cm

Circumference of circular clock = 2πr

= 2 x 3.14 x 15 = 94.2 cm

Therefore, the tip of the minute hand moves 94.2 cm in 1 hour.

In 1945 the Allied forces included the US, UK, USSR and France.

(a) Element of electric heater- high melting point

(b) Element of fuse wire - low melting point

Let focal length of converging and diverging lenses be + f and - f respectively.

Power of converging len P₁ = 1/f, Power of diverging lens P₂ = - 1/f

∴ Power of combination P = P₁ + P₂ = 1/f - 1/f = 0

∴ Focal length of combination F 1/P = 1/0 = ∞ (infinite)​

F = ∞.

If cork is not formed in older stems or roots, the outer tissues will rupture due to increase in girth which expose the interior to dessication and infection.

∠QOR + ∠QPR = 180° (Supplementary angles) 

⇒ ∠QOR + 46° = 180° 

⇒ ∠QOR = 180° – 46° = 134°.

angQOR = 360^o -2×90^o -46^o =134^o

∠QPR = ∠50°   (Given) 

∴ ∠QOR = 180° – 50° = 130°

ΔOQR is an isosceles triangle. 

From ΔOQR

∠OQR = ∠ORQ = (180 - 130)/2 

= 50/ 2 

= 25°

Camels can walk easily in the desert because of their wide feet. Their wide feet allow the weight of their body to act on a larger surface of land reducing the pressure exerted on the land by the camel. We can say this as we know that pressure exerted and area are inversely proportionate. 

Hot spots are placed within the mantle where rocks melt to generate magma.

(i) X – Violet 

Y – Red 

(ii) This happens due to the following reasons: 

(a) Due to difference in speed of different colours 

(b) Due to difference in wavelength and frequency 

(c) Due to refractive index of glass is different for different colours of light.

(i) X – Violet 

    Y – Red 

(ii) This happens due to the following reasons: 

(a) Due to difference in speed of different colours 

(b) Due to difference in wavelength and frequency 

(c) Due to refractive index of glass is different for different colours of light.

 Visible spectrum is the band of coloured components of a white light beam .

When a beam of light enters a prism, it gets refracted and splits into its seven constituent colours. This splitting of the light ray occurs because of the different angles of bending of each colour. Hence, each colour passing through the prism bends at different angles with the respect to the incident beam. This gives rise to the formation of the colour spectrum.

(i) The phenomenon is called dispersion. 

(ii) X — Violet Y — Red 

(iii) Different colours of white light bend through different angles with respect to the incident beam of light due to difference in speed of light of different wavelengths. 

Let us understand the use of Stokes law to derive the terminal velocity of a body falling through a viscous liquid,under gravity  

Weight of the body = mg  = Vρg  

W = 4/3 πr³ρg  

where r is the radius of the body, r is density, g is the gravity due to upward viscous drag F_v = 6phvr (Stokes law).  

where h is coefficient of viscosity, v is the velocity of body, r is radius of the body.  

Upthrust or Buoyant force F_T = weight of displaced liquid  

= Volume of body  

x density of liquid x acceleration due to gravity  

F_T = Vρg  

= 4/3 πr³σg  

When the body moves with terminal velocity,  

that is, V = V_T, total upward force = downward force  

6πη V_T r + 4/3 πr³σg = 4/3 πr³ρg  

6πη V_T r = = 4/3 πr³ (ρ - σ)g  

V_T = [2r²(ρ - σ)g]/9η

(i) Standard equation of magnetic field is

B_y = B₀sin(ωt + kx)T

Comparing this equation with the given equation, we get

B₀ = 8 x 10^-6T, ω = 2 x 10¹¹ rad s^-1, k = 2π/λ = 300π

wavelength  λ  = 2π/300π = 1/150m

(ii) E₀B₀c = 8 x 10^-6 x 3 x 10⁸ = 2.4 x 10³Vm.

According to right hand system of vector E, vector B, vector K, the electric field oscillates along negative Z-axis, so equation is

E_z = - 2.4 x 10³sin(2 x 10¹¹t + 300πx)Vm^-1.

A pencil when dipped in water in a glass tumbler appears to be bent at the interface of air and water due to phenomenon of refraction of light.

As we know, different materials have different refractive index. So, the amount of refraction for different media will be different. Hence, pencil will appear to be bent more or less depending on the refractive index of the medium.

for a dipole in external Electric field

U = -pEcosθ

(i) when θ = 0, cosθ = 1, u = -pE Minimum potential energy dipole is in stable equilibrium

(ii) when θ = π, cosθ = cosπ = -1,

and u = pE (Maximum Potential Energy)

dipole is in unstabie equilibrium.

B. Present generation fulfils its needs while considering the needs of the future generation as well.

A. Heroism and Justice 

C. Democratic Government is coping with multiple pressures through accommodation 

Belgium is a small country in Europe and share borders with France, the Netherlands, Germany and Luxembourg.

The Correct option is (A) Red

Bile juice is secreted from Liver.

Frederick Griffith (1928) conducted experiments with Streptococcus pneumoniae (bacterium causing pneumonia). He observed two strains of this bacterium—one forming smooth shiny colonies (S-type) with capsule, while other forming rough colonies (R-type) without capsule. When live S-type cells were injected into mice, they died due to pneumonia. When live R-type cells were injected into mice, they survived. When heat-killed S-type cells were injected into mice, they survived and there were no symptoms of pneumonia. When heat-killed S-type cells were mixed with live R-type cells and injected into mice, they died due to unexpected symptoms of pneumonia. 

He concluded that heat-killed S-type bacteria caused a transformation of the R-type bacteria into S-type bacteria but he was not able to understand the cause of this bacterial transformation.

Embryo is present in the womb of a mother where it is connected with the uterine wall of mother by placenta. The foetus receives oxygen, nourishment and other life supporting things from mother through this placenta.

Commensalism.

(i) Given: a = 21, b = 18 

We have a -(-b) = a =+ b 

Putting the values in L.H.S. =

a - (-b) = 21 -(-18) = 21 + 18 = 39 

Putting the values in R.H.S. 

= a + b = 21 + 18 = 39 

Since, L.H.S. = R.H.S Hence, verified

(ii) Given: a = 118, b = 125 

We have a -(-b) = a =+ b 

Putting the values in L.H.S. =

a - (-b) = 118 -(-125) = 118 + 125 = 243

Putting the values in R.H.S. 

= a + b = 118 + 125 = 243

Since, L.H.S. = R.H.S Hence, verified

(iii) Given: a = 75, b = 84

We have a -(-b) = a =+ b 

Putting the values in L.H.S. =

a - (-b) = 75 -(-84) = 75 + 84 = 159 

Putting the values in R.H.S. 

= a + b =75 + 84 = 159

Since, L.H.S. = R.H.S Hence, verified

(iv) Given: a =28, b = 11

We have a -(-b) = a =+ b 

Putting the values in L.H.S. =

a - (-b) = 28-(-11) = 28 + 11 = 39 

Putting the values in R.H.S. 

= a + b = 28 + 11 = 39 

Since, L.H.S. = R.H.S Hence, verified

Given,

the initial velocity = 0 m/s

acceleration = 4 m/s²

time = 30 s

According to laws of motion.

S = ut + 1/2 at²

S = 1/2 at²

S = 1/2 (4)(30)²

S = 1/2 x 4 x 30 x 30

s = 3600/2 m

S = 1800 m

The distance traveled before takeoff is 1800 m.

(i) Attenuation :
The loss of strength of a signal while . propagating through a medium is known as attenuation.

(ii) Demodulation :
The process of retrieval of information from the carrier wave at the receiver is termed demodulation. This is the reverse process of modulation.

Brewster’s law :
The law states that the tangent of the polarising angle of incidence of a transparent medium is equal to its refractive index. The light incident at this angle when reflects back is perfectly polarised.
p = tan i_p
The refractive index of a material depends on the colour or wavelength of light. As the polarising angle depends on refractive index (p = tan i_p ), so it also depends on wavelength of light.

It cuts the DNA between bases G and A on both the strands only when the sequence GAATTC is present in the DNA. 

The orchid bears flowers which resemble the female wasp in colour, smell as well as appearance. The male pollinators mistake them as their female counterparts. In their process of their pseudocopulating, they pollinate the flower.

5' – GAATTC – 3' 

3' – CTTAAG – 5'

EcoRI is a restriction endonuclease, obtained from an E. coli bacterium. 

R represents the name of the strain.

Ex situ is a desirable approach to protect the wild cat. The organism is protected outside their natural habitat where special care is taken to protect them. By using cryopreservation techniques, gametes of threatened species can be preserved under very low temperature.

The spleen is a large bean-shaped organ. It mainly contains lymphocytes and phagocytes. It acts as a filter of the blood by trapping blood-borne microorganisms. Spleen also has a large reservoir of erythrocytes.

(a) M is the repressor. 

(b) When repressor binds with the operator, transcription stops. 

(c) An inducer prevents the binding of repressor to operator and thus transcription starts.

Pollination in Ophrys: The petals of the Ophrys resembles the female of a bee species in size, colour and odour, etc. Male bee mistakes the Ophrys for female bee and tries to copulate. Few pollen grains adhered with the body of the male bee fall over stigma of the flower thereby leading to pollination.

The milk that comes out of the mammary glands during initial days of lactation is called colostrum. It contains several antibodies absolutely essential for developing resistance for the new-born babies.

Advantages of GMOs: 

(i) tolerant against abiotic stresses (cold, drought, salt, heat). 

(ii) reduces reliance on chemical pesticides. 

(iii) reduces post-harvest losses. 

(iv) increase efficiency of mineral usage by plants.