datavorous/entrance-exam-dataset huggingface dataset:
One bag contains 5 white balls and 3 black balls and a second bag contains 2 white balls and 4 black balls. One ball is drawn from the first bag and placed unseen in the second bag. What is the probability that a ball now drawn from the second bag is black?

Options:
A $\frac{15}{56}$
B $\frac{35}{56}$
C $\frac{37}{56} \quad$
D $\frac{25}{48}$

The correct answer is:
$\frac{35}{56}$

Solution:
Bag I. has 5 white $+3$ black balls. Bag II. has 2 white $+4$ black balls.
$\mathrm{P}(\text { Black })_{1 \text { st bag }}=\frac{3}{8} \& \mathrm{P}(\text { White })_{1 \text { st bag }}=\frac{5}{8}$
If one ball is drawn from bag I \& placed in bag II, bag II will have 7 balls.
If black ball is drawn, then; bag II contains. $2 \mathrm{~W}+5$ Black balls $=7$ balls $\mathrm{P}($ black ball from bag 1 and black ball from bag 2 )
$=\frac{3}{8} \times \frac{5}{7}=\frac{15}{56}$
If ball is white then bag II has $3 \mathrm{w}+4$ black balls $\mathrm{P}$ (white ball from bag 1 and black ball from bag 2)
$=\frac{5}{8} \times \frac{4}{7}=\frac{20}{56}$
$\Rightarrow$ Prob(blackball) $_{\text {bagII }}=\frac{15}{56}+\frac{20}{56}=\frac{35}{56}$

Topic: Mathematics, Probability, NDA, NDA 2008 (Phase 1)
One Dobson unit is equal to a layer of pure ozone _______ in thickness at standard temperature and pressure.

Options:
A 1 mm
B 0.1 mm
C 0.01 mm
D 0.001 mm

The correct answer is:
0.01 mm

Solution:
The thickness of the ozone in a column of air from the ground to the top of the atmosphere is measured in terms of Dobson units. The number of molecules of ozone required to produce a layer of pure ozone 0.01 mm thick at a pressure of 1 atmosphere and 0oC is one Dobson unit.

Topic: Biology, Environmental Issues, NEET
One mole of an ideal gas at standard temperature and pressure occupies 22.4 L (molar volume). What is the ratio of molar volume to the atomic volume of a mole of hydrogen? (Take the size of hydrogen molecule to be about $1 Å$ ). Why is this ratio so large?

Options:

None

Solution:
8 Volume of one mole of ideal gas,
$V_{\mathrm{g}}=22.4$ litre $=22.4 \times 10^{-3} \mathrm{~m}^3$
Radius of hydrogen molecule $=\frac{1 Å}{2}$
$$
=0.5 Å=0.5 \times 10^{-10} \mathrm{~m}
$$
Volume of hydrogen molecule $=\frac{4}{3} \pi r^3$
$$
\begin{aligned}
&=\frac{4}{3} \times \frac{22}{7}\left(0.5 \times 10^{-10}\right)^3 \mathrm{~m}^3 \\
&=0.5238 \times 10^{-30} \mathrm{~m}^3
\end{aligned}
$$
One mole contains $6.023 \times 10^{23}$ molecules.
$\therefore$ Volume of one mole of hydrogen,
$$
\begin{aligned}
V_{\mathrm{H}} &=0.5238 \times 10^{-30} \times 6.023 \times 10^{23} \mathrm{~m}^3 \\
&=3.1548 \times 10^{-7} \mathrm{~m}^3
\end{aligned}
$$
Now, $\frac{V_{\mathrm{g}}}{V_{\mathrm{H}}}=\frac{22.4 \times 10^{-3}}{3.1548 \times 10^{-7}}=7.1 \times 10^4$
The ratio is very large. This is because the interatomic separation in the gas is very large compared to the size of a hydrogen molecule.

Topic: Physics, Units and Dimensions
One mole of ethanol is produced reacting graphite, H2 and O2 together. The standard enthalpy of formation is − 277.7 kJ  mol −1 . Calculate the standard enthalpy of the reaction when 4 moles of graphite is involved.

Options:
A − 277.7 kJ/mol
B − 555.4 kJ/mol
C − 138.85 kJ/mol
D − 69.42 kJ/mol

The correct answer is:
− 555.4 kJ/mol

Solution:
2 C(s) +  1 2 O 2 (g) + 3  H 2 (g)→ C 2 H 5 OH(l);   ΔH f  = −277.7 kJ
By doubling the reaction,
4 C(s) +  O 2 (g) + 6  H 2 (g)→2  C 2 H 5 OH;   ΔH f  = 2 ×​ −277.7
=− 555.4 kJ

Topic: Chemistry, Thermodynamics (C), NEET
One of endangered species of Indian medicinal plants is that of:

Options:
A Ocimum
B garlic
C Nepenthes
D Podophyllum.

The correct answer is:
Podophyllum.

Solution:
Podophyllum is one of the endangered species of Indian medicinal plants which used to remove benign (not cancer) growths, such as certain kinds of warts. It works by destroying the tissue of the growth.

Topic: Biology, Biodiversity and its Conservation, NEET, NEET 2007
One of the angles of a triangle is $1 / 2$ radian and the other is $99^{\circ}$. What is the third angle in radian measure?

Options:
A $\frac{9 \pi-10}{\pi}$
B $\frac{90 \pi-100}{7 \pi}$
C $\frac{90 \pi-10}{\pi}$
D None of these

The correct answer is:
None of these

Solution:
Let $\angle \mathrm{A}=\frac{1}{2}$ radian, $\angle \mathrm{B}=99^{\circ}=\frac{99^{\circ} \times \pi}{180^{\circ}}=\frac{11 \pi}{20}$
We know that, $\angle \mathrm{A}+\angle \mathrm{B}+\angle \mathrm{C}=\pi$
(by angle sum property of triangle) $\Rightarrow \frac{1}{2}+\frac{11 \pi}{20}+\angle \mathrm{C}=\pi$
$\Rightarrow \quad \angle C=\pi-\frac{11 \pi}{20}-\frac{1}{2}=\frac{9 \pi-10}{20}$
Hence, the third angle in radian is $\frac{9 \pi-10}{20}$.

Topic: Mathematics, Trigonometric Ratios & Identities, NDA, NDA 2010 (Phase 2)
One of the ex situ conservation methods for endangered species is

Options:
A wildlife sanctuaries
B biosphere reserves
C cryopreservation
D national parks.

The correct answer is:
cryopreservation

Solution:
Ex situ conservation is the preservation of components of biological diversity outside their natural habitats for example: in zoos, aquaria, botanical gardens and gene banks. They are the most conventional methods of ex-situ conservation, all of which house whole, protected specimens for breeding and reintroduction into the wild when necessary and possible. Rest of the given options are examples of in situ conservation.

Topic: Biology, Biodiversity and its Conservation, AIIMS, AIIMS 2005
One of the major difficulties in the biological control of insect pest is that

Options:
A the predator develops a preference to other diets and may itself become a pest
B the predator does not always survive when transferred to a new environment
C the method is less effective as compared with the use of insecticides
D the practical difficulty of introducing the predator to specific areas.

The correct answer is:
the predator develops a preference to other diets and may itself become a pest

Solution:
The predator develops a preference to other diets and can give unforeseen negative results that could outweigh all benefits. For example, when the mongoose was introduced in Hawaii in order to control the rat population, it preyed on the endemic birds of Hawaii, especially their eggs, more often than it ate the rats. As most of the birds feed on insect and keep insect population low. The mangoose who destroy birds acts as secondary pest.

Topic: Biology, Organisms and Populations, AIIMS, AIIMS 2008
One of the roots of a quadratic equation with real coefficients
is $\frac{1}{(2-3 \mathrm{i})}$. Which of the following implications is/are true?
1) The second root of the equation will be $\frac{1}{(3-2 i)}$.
2) The equation has no real root.
3) The equation is $13 x^{2}-4 x+1=0$. Which of the above is/are correct?

Options:
A 1 and 2 only
B 3 only
C 2 and 3 only
D 1,2 and 3

The correct answer is:
2 and 3 only

Solution:
If one root is $\frac{1}{2-3 i}$ ie, $\frac{2+3 i}{4+9}=\frac{2}{13}+\frac{3}{13}$, then another
root will be $\frac{2}{13}-\frac{3 i}{13}$ ie, $\frac{1}{2+3 i}$. [Since complex roots are conjugate] So, statement $(1)$ is not correct. Since, quadratic equation has two roots thus this equation has only imaginary roots. Statement (2) is correct. The equation is $\mathrm{x}^{2}-($ Sum of roots $) \mathrm{x}+($ Product of roots $)=0$
Sum of roots $=\frac{1}{2-3 i}+\frac{1}{2+3 i}=\frac{4}{13}$
Product of roots $=\frac{1}{2-3 \mathrm{i}} \times \frac{1}{2+3 \mathrm{i}}=\frac{1}{13}$
$\Rightarrow \quad x^{2}-\frac{4}{13} x+\frac{1}{13}=0 \Rightarrow 13 x^{2}-4 x+1=0$
$\Rightarrow$ So, statement 3 is correct. Thus, (2) and (3) statements are correct.

Topic: Mathematics, Sequences and Series, NDA, NDA 2006 (Phase 1)
One of the roots of the quadratic equation $a x^{2}+b x+c=0$, $a \neq 0$ is positive and the other root is negative. The condition for this to happen is

Options:
A $a>0, b>0, c>0$
B $a \geq 0, b < 0, c>0$
C $a < 0, b>0, c < 0$
D $a < 0, c>0$

The correct answer is:
$a \geq 0, b < 0, c>0$

Solution:
Since one root of $a x^{2}+b x+c=0, a \neq 0$ is positive and another root is negative which is possible only if $a>0$, $b < 0, c>0$

Topic: Mathematics, Quadratic Equation, NDA, NDA 2011 (Phase 1)
One of the roots of
$\left|\begin{array}{ccc}x+a & b & c \\ a & x+b & c \\ a & b & x+c\end{array}\right|=0$ is

Options:
A $a b c$
B $a+b+c$
C $-(a+b+c)$
D $-a b c$

The correct answer is:
$-(a+b+c)$

Solution:
$\left|\begin{array}{ccc}x+a & b & c \\ a & x+b & c \\ a & b & x+c\end{array}\right|=0$
Applying, $C_{1} \rightarrow C_{1}+C_{2}+C_{3}$
$\left|\begin{array}{ccc}(a+b+c+x) & b & c \\ (a+b+c+x) & x+b & c \\ (a+b+c+x) & b & c+x\end{array}\right|=0$
$\begin{array}{l}
(a+b+c+x)\left|\begin{array}{ccc}
1 & b & c \\
1 & x+b & c \\
1 & b & x+c
\end{array}\right|=0 \\
C_{2} \rightarrow C_{2}-C_{1}, C_{3} \rightarrow c_{3}-C_{1} \\
(a+b+c+x)\left|\begin{array}{lll}
1 & b & c \\
0 & x & 0 \\
0 & 0 & x
\end{array}\right|=0 \\
(a+b+c+x) 1 \cdot x^{2}=0 \\
x=0,-(a+b+c) \quad(\because x \neq 0)
\end{array}$

Topic: Mathematics, Determinants, NDA, NDA 2014 (Phase 1)
One radian is approximately equal to which one of the following?

Options:
A $90^{\circ}$
B $180^{\circ}$
C $57^{\circ}$
D $47^{\circ}$

The correct answer is:
$57^{\circ}$

Solution:
1 radian is approximately equal to $57^{\circ}$

Topic: Mathematics, Trigonometric Ratios & Identities, NDA, NDA 2009 (Phase 1)
One root ofthe equation $x^{2}=p x+q$ is reciprocal of the othe and $\mathrm{p} \neq \pm 1$. What is the value of q?

Options:
A $q=-1$
B $\mathrm{q}=1$
C $q=0$
D $\mathrm{q}=\frac{1}{2}$

The correct answer is:
$q=-1$

Solution:
Let the roots of the equation $x^{2}-p x-q=0$ be and $\frac{1}{\alpha}$
$\Rightarrow$ Product of roots $=\alpha \cdot \frac{1}{\alpha}=-\frac{\mathrm{q}}{1}$
$1=-\mathrm{q} \Rightarrow \mathrm{q}=-1$

Topic: Mathematics, Quadratic Equation, NDA, NDA 2008 (Phase 1)
Organisms called Methanogens are most abundant in a

Options:
A cattle yard
B polluted stream
C hot spring
D sulphur rock

The correct answer is:
cattle yard

Solution:
Methanogens are present in the gut of several ruminants animals such as cows and buffaloes and they are responsible for the production of methane (biogas) from the dung of these animals. Thus, they are most abundant in a cattle yard.

Topic: Biology, Microbes in Human Welfare, NEET, NEET 2011 (Screening)
Organisms called methanogens are most abundant in

Options:
A Sulphur rock
B Cattle yard
C Polluted stream
D Hot spring

The correct answer is:
Cattle yard

Solution:
Methanogenic archaea reside primarily in the rumen and the lower segments of the intestines of ruminants, where they utilize the reducing equivalents derived from rumen fermentation to reduce carbon dioxide, formic acid or methylamines to methane (CH4).

Topic: Biology, Biological Classification, NEET
Organs which differ in origin but perform similar functions :

Options:
A analogous
B homologous
C vetigial
D none of these

The correct answer is:
analogous

Solution:
The organs which have similar function but are different in their structure and origin are called analogous organs.
The organs which have same fundamental structure and origin but function may be similar or different, are called homologous organs.
The organs which are present in reduced form and do not correspond to the fully developed functional organs to related animals are called vestigial organs.

Topic: Biology, Evolution, JIPMER, JIPMER 2006
Out of 7 consonants and 4 vowels, words are to be formed by involving 3 consonants and 2 vowels. The number of such words formed is :

Options:
A 25200
B 22500
C 10080
D 5040

The correct answer is:
25200

Solution:
Number of words $=5 ! \times{ }^{7} \mathrm{C}_{3} \times{ }^{4} \mathrm{C}_{2}$
$=120 \times \frac{7 !}{4 ! 3 !} \times \frac{4 !}{2 ! 2 !}=25200$

Topic: Mathematics, Permutation Combination, NDA, NDA 2014 (Phase 1)
Out of 15 points in a plane, $\mathrm{n}$ points are in the same straight line. 445 triangles can be formed by joining these points. What is the value of $n ?

Options:
A 3
B 4
C 5
D 6

The correct answer is:
5

Solution:
Here, ${ }^{15} \mathrm{C}_{3}-{ }^{\mathrm{n}} \mathrm{C}_{3}=445$
$\Rightarrow{ }^{\mathrm{n}} \mathrm{C}_{3}=\frac{15 !}{3 ! 12 !}-445$
$\Rightarrow{ }^{n} C_{3}=10$
${ }^{3} \mathrm{C}_{3}=1 ;{ }^{4} \mathrm{C}_{3}=4 ;{ }^{5} \mathrm{C}_{3}=10$
$\Rightarrow n=5$

Topic: Mathematics, Permutation Combination, NDA, NDA 2016 (Phase 2)
Out of 32 persons, 30 invest in National Savings Certificates and 17 invest in shares. What is the number of persons who
invest in both?

Options:
A 13
B 15
C 17
D 19

The correct answer is:
15

Solution:
Let $\mathrm{N}=$ National savings certificates $\mathrm{S}=$ Shares Total no. of persons $=32$ No. of persons who invest in National savings certificates $=30$ No. of persons who invest in shares $=17$
Therefore $n(N \cup S)=32, n(N)=30, n(S)=17$
We know that,
$n(N \cup S)=n(N)+n(S)-n(N \cap S)$
$\Rightarrow 32=30+17-n(N \cap S)$
$\Rightarrow n(N \cap S)=47-32=15$

Topic: Mathematics, Sets and Relations, NDA, NDA 2010 (Phase 1)
Out of the following four dimensional quantities. which one qualifies to be called a dimensional constant?

Options:
A Acceleration due to gravity
B Surface tension of water
C Weight of a standard kilogram mass
D Velocity of light in vacuum

The correct answer is:
Velocity of light in vacuum

Solution:
The velocity of light in vacuum is $3 \times 10^{8} \mathrm{~m} / \mathrm{s}$, which is a dimensional constant.

Topic: Physics, Units and Dimensions, COMEDK, COMEDK 2017
Out of the following four dimensional quantities, which one qualifies to be called a universal constant?

Options:
A Acceleration due to gravity
B Surface tension of water
C Weight of a standard kilogram mass
D The velocity of light in vacuum

The correct answer is:
The velocity of light in vacuum

Solution:
The velocity of light in vacuum is independent of any other constant so it is a universal constant.
c=3×108 m s-2

Topic: Physics, Units and Dimensions, NEET
Out of the following graphs, which graph shows the correct relation (graphical representation) for LC Parallel resonant circuit?

Options:
A
B
C
D

The correct answer is:

Solution:
At parallel resonance, current is minimum.

Topic: Physics, Alternating Current, MHT CET, MHT CET 2017
Out of the fundamental forces in nature, maximum and minimum range is respectively for

Options:
A gravitational force, weak nuclear force.
B gravitational force, electromagnetic force.
C strong nuclear force, electromagnetic force.
D electromagnetic force, gravitational force.

The correct answer is:
gravitational force, weak nuclear force.

Solution:
Gravitational force,weak nuclear force

Topic: Physics, Electromagnetic Waves, MHT CET, MHT CET 2020 (14 Oct Shift 2)
Outof 500 first year students, 260 passed in the first semester and 210 passed in the second semester. If 170 did not pass in either semester, how many passed in both semesters?

Options:
A 30
B 40
C 70
D 140

The correct answer is:
140

Solution:
Let $\mathrm{A}=$ no. of students passed in the first semester. $\mathrm{B}=$ no. of students passed in second semester Given, $n(A)=260, n(B)=210$
$\mathrm{n}(\overline{\mathrm{A}})=$ no. of students did not pass in first semester.
$=500-260=240$
Similarly, $\mathrm{n}(\overline{\mathrm{B}})=500-210=290$
Thus, we have $\mathrm{n}(\overline{\mathrm{A}} \cup \overline{\mathrm{B}})=170$,
$\mathrm{n}(\overline{\mathrm{A}})=240, \mathrm{n}(\overline{\mathrm{B}})=290$
$\mathrm{n}(\overline{\mathrm{A}} \cup \overline{\mathrm{B}})=\mathrm{n}(\overline{\mathrm{A}})+\mathrm{n}(\overline{\mathrm{B}})-\mathrm{n}(\overline{\mathrm{A}} \cap \overline{\mathrm{B}})$
$\Rightarrow 170=240+290-\mathrm{n}(\overline{\mathrm{A}} \cap \overline{\mathrm{B}})$
$\Rightarrow \mathrm{n}(\overline{\mathrm{A}} \cap \overline{\mathrm{B}})=360$
So, n (students passed in both semester) $=500-360=140$

Topic: Mathematics, Sets and Relations, NDA, NDA 2012 (Phase 1)
Oxidation potential of unimoles of calomel is

Options:
A $+0.25 \mathrm{~V}$
B $0.00 \mathrm{~V}$
C $+0.287 \mathrm{~V}$
D $-0.28 \mathrm{~V}$

The correct answer is:
$-0.28 \mathrm{~V}$

Solution:
Calomel is used as a secondary reference electrode. Since $\mathrm{Hg}$ is less reactive than $\mathrm{H}$, its standard reduction potential is positive. Hence, its standard oxidation potential must be negative, $i e,-0.28 \mathrm{~V}$. [As standard reduction potential = $-$ standard oxidation potential.]

Topic: Chemistry, Electrochemistry, MHT CET, MHT CET 2010
$\mathrm{P}(2,2)$ is a point on the parabola $\mathrm{y}^{2}=2 \mathrm{x}$ and $\mathrm{A}$ is its vertex. $\mathrm{Q}$ is another point on the parabola such that $\mathrm{PQ}$ is perpendicular to AP. What is the length of PQ?

Options:
A $\sqrt{2}$
B $2 \sqrt{2}$
C $4 \sqrt{2}$
D $6 \sqrt{2}$

The correct answer is:
$6 \sqrt{2}$

Solution:
Equation of parabola is $y^{2}=2 x$, so vertex lies at origin So, co-ordinates of vertex are $\mathrm{A}(0,0)$. Let $\left(x_{1}, y_{1}\right)$ be the co-ordinates of the point $Q$
$\therefore \quad y_{1}^{2}=2 x_{1}$ $. .(\mathrm{i})$
and slope of $\mathrm{PQ}=\frac{\mathrm{y}_{1}-2}{\mathrm{x}_{1}-2}$
[co-ordinates of $\mathrm{P}$ is $(2,2)$ as given]
Also, slope of $\mathrm{AP}=\frac{2-0}{2-0}=1$
Since, $\mathrm{PQ}$ and $\mathrm{AP}$ are perpendicular to each other, hence, slope of AP $\times$ Slope of $P Q=-1$
So, $1 \times\left(\frac{y_{1}-2}{x_{1}-2}\right)=-1$
$\Rightarrow \quad y_{1}-2=-x_{1}+2$
$\Rightarrow x_{1}+y_{1}=4 \Rightarrow x_{1}=4-y_{1}$
Putting value of $\mathrm{x}$, in equation (i)
$y_{1}^{2}=8-2 y_{1}$ or $y_{1}^{2}+2 y_{1}-8=0$
$\Rightarrow \quad y_{1}=-4$ and 2
Hence, co-ordinates of point $\mathrm{Q}$ are $(8,-4)$.
So, required length $P Q=\sqrt{(8-2)^{2}+(-4-2)^{2}}$
$=\sqrt{36+36}=\sqrt{72}=6 \sqrt{2}$

Topic: Mathematics, Parabola, NDA, NDA 2006 (Phase 1)
Ph-C≡C-CH3→Hg2+/H2SO4aqA

The major product (A) formed is -

Options:
A
B

C

D

The correct answer is:

Solution:

Topic: Chemistry, Hydrocarbons, NEET
$p, q, r, s, t$, are five numbers such that the average of $p, q$ and $r$ is 5 and that of s and $t$ is 10 . What is the average of all the five numbers?

Options:
A $7.75$
B $7.5$
C 7
D 5

The correct answer is:
7

Solution:
According to question $\mathrm{p}+\mathrm{q}+\mathrm{r}=5 \times 3=15$ $+\mathrm{t}=10 \times 2=20$
From equations(i) and (ii) $20=3$
Average $\mathrm{p}, \mathrm{q}, \mathrm{r}, \mathrm{s}$ and $\mathrm{t}=\frac{35}{5}=7$

Topic: Mathematics, Sets and Relations, NDA, NDA 2014 (Phase 1)
Parenchyma is usually present in,

i) Cortex
ii) Phloem fibre
iii) Pericycle
iv) Pith
v) Hypodermis
vi) Medullary rays
vii) Xylem fibres
viii) Mesophyll tissue

Options:
A i, iii, iv, vi, viii
B i, ii, iii, iv, vi
C i, v, vi, vii
D i, ii, iv,vi

The correct answer is:
i, iii, iv, vi, viii

Solution:
Parenchyma is the most abundant tissue commonly known as filling tissue which is present in all plant parts. Phloem fibres (bast fibres) are made up of sclerenchymatous cells. The hypodermis is made up of collenchymatous or sclerenchymatous cells.

Topic: Biology, Anatomy of Flowering Plants, NEET
Periderm includes :

Options:
A cork cambium only
B cork cambium and cork
C cork and secondary cortex
D cork cambium, cork and secondary cortex

The correct answer is:
cork cambium, cork and secondary cortex

Solution:
Periderm formation occurs in the root and stems of dicots and gymnosperm in extra stelar region with the help of cork cambium. Periderm is external secondary protective tissue and compreses of cork, cork cambium and secondary cortex.

Topic: Biology, Anatomy of Flowering Plants, JIPMER, JIPMER 2004
Periderm includes

Options:
A Cork
B Cork cambium
C Secondary cortex
D All of these

The correct answer is:
All of these

Solution:
The mechanism in secondary growth in the cortical region of dicot stem involves the process of dedifferentiation. Few of the cortical cells (in the form of few layers) become meristematic (cork cambium or phellogen) and cut off new cells - cork or phellem (towards the outer side) and phelloderm or secondary cortex (on the inner side). Periderm includes cork or phellem (suberised cell wall), cork cambium or phellogen and secondary cortex or phelloderm.

Topic: Biology, Anatomy of Flowering Plants, NEET
Peripheral region of secondary xylem, which is light in color and which causes conduction of water and minerals is known as

Options:
A Heartwood (duramen)
B Sapwood (alburnum)
C Spring wood
D Autumn wood

The correct answer is:
Sapwood (alburnum)

Solution:
The peripheral light coloured wood which is functional and causes movement of water and minerals is called as sap wood, and the central dark coloured wood which is non functional is called as heart wood. Sap wood consists of secondary xylem only but heart wood consists of both primary and secondary xylem.

Topic: Biology, Anatomy of Flowering Plants, NEET
Periplastidial space is found in

Options:
A between two membranes of a chloroplast.
B between two thylakoids.
C between two intergrana lamellae.
D between lumen of thylakoids.

The correct answer is:
between two membranes of a chloroplast.

Solution:
Between two membranes of chloroplast; i.e. space between primary and secondary wall of chloroplast.

Topic: Biology, Cell - The Unit of Life, NEET
Perisperm is :

Options:
A degenerate part of synergids
B peripheral part of endosperm
C degenerate part of secondary nucleus
D remnant of nucellus

The correct answer is:
remnant of nucellus

Solution:
Perisperm is the remnant of nucellus. It is found in Piperaceae and Scitaminaceae. It is formed when the nucellus is not completely used up and is present in the form of a thin layer in the seed enclosing the embryo and the endosperm.

Topic: Biology, Sexual Reproduction in Flowering Plants, JIPMER, JIPMER 2006
Phellogen and phellem respectively denote

Options:
A cork and cork cambium
B cork cambium and cork
C secondary cortex and cork
D cork and secondary cortex

The correct answer is:
cork cambium and cork

Solution:
In the dicot stem the cortical cells gets differentiated to give rise to another meristematic tissue, which is called cork cambium or phellogen. On the other side, it forms phellem (cork) and in the inner region it forms secondary cortical cells (phelloderm).

Topic: Biology, Anatomy of Flowering Plants, JIPMER, JIPMER 2017
Phellogen and phellem respectively denote

Options:
A
cork and cork cambium

B
cork cambium and cork

C
secondary cortex and cork

D
cork and secondary cortex

The correct answer is:
cork cambium and cork

Solution:
Cork cambium is also called phellogen and cork cells is called cork or phellem.

Topic: Biology, Anatomy of Flowering Plants
Photosynthetic efficiency is represented by XIncident total solar radiation.

The 'X' in this equation represents

Options:
A Gross primary productivity
B Net primary productivity
C Secondary productivity
D none of these

The correct answer is:
Gross primary productivity

Solution:
The efficiency of photosynthesis is the amount of biomass a plant can produce in a given amount of light. The amount of biomass produced by producers in an ecosystem is gross primary productivity.
Photosynthetic efficiency = Gross primary productivity / Incident total solar radiation.

Topic: Biology, Ecosystem, NEET
Phototropic curvature is the result of uneven distribution of

Options:
A gibberellin
B phytochrome
C cytokinins
D auxin

The correct answer is:
auxin

Solution:
Darwin and his son Francis used germinating oat (Avena sativa) and canary grass (Phalaris canariensis) seedling in their experiments and hypothesized that when shoots were illuminated from one side, they bent forward the light in response to an 'influence', that was transmitted downward from its source at the tip of the shoot. Paal concluded that the tip secretes a substance, which promotes the growth of part below it. In 1926, Frits Went discovered that some unidentified compound probably caused curvature of oat coleoptile towards light, ie, phototropism. The compound (auxin) found by Went is relatively abundant in coleoptile tips.

Topic: Biology, Plant - Growth and Development, NEET, NEET 2010 (Screening)