Which of the following is not correct for rods? I. Twilight vision is the function of the rods II. It is responsible for daylight vision sometimes III. The rods contain a protein called rhodopsin IV. Rods are photoreceptor cells Choose the correct option

Rod cells are responsible for night or twilight vision only. Both (a) and (b), i.e., cones and rods

The correct Option is "Only II"

Which of the following is not correct regarding the properties of ionic compounds?

Ionic compounds are good conductor of electricity in molten or in solution state. However, they are bad-conductor in solid state.

Ionic compounds have high metling and boiling points

Their reaction velocity in aqueous medium is very high

The correct Option is "Ionic compounds in their molten and aqueous solutions do not conduct electricity"

They are highly soluble in polar solvents

Which of the following is not correct for gasrtulation?

Gasrtulation is characterized by the presence of archenteron, three germinal layers (ectoderm, mesoderm, and endoderm) and morphogenetic movements.

The correct Option is "Some blastomeres and blastocoel degenerate"

Which of the following is not correct with respect to bond length of the species?

$\begin{array}{l} {{\rm{O}}_2} < {\rm{O}}_2^ - \\ Bond\,order\\ {{\rm{C}}_2} = 2\\ {\rm{C}}_2^{2 - } = 3\\ {{\rm{B}}_2} = 2\\ {\rm{B}}_2^ + = 1.5\\ {\rm{L}}{{\rm{i}}_2} = 1\\ {\rm{Li}}_2^ + = 0.5\\ {{\rm{N}}_2} = 3\\ {\rm{N}}_2^ + = 2.5\\ {{\rm{O}}_2} = 2\\ {\rm{O}}_2^ - = 1.5 \end{array}$

${{\rm{C}}_2} > {\rm{C}}_2^{2 - }$

${\rm{Li}}_2^ + > {\rm{L}}{{\rm{i}}_2}$

The correct Option is "${{\rm{O}}_2} > {\rm{O}}_2^ - $"

Which of the following is not correct?

$2{\rm{N}}{{\rm{a}}_2}{{\rm{S}}_2}{{\rm{O}}_3} + {{\rm{I}}_2} \to {\rm{N}}{{\rm{a}}_2}{{\rm{S}}_4}{{\rm{O}}_6} + 2{\rm{NaI}}$ sodium thiosulphate sodium tetrathionate

Iodine oxidises sodium thiosulphate to sodium tetrathionate.

Sodium thiosulphate is soluble in water.

Ozone is used to identify the presence of unsaturation in alkenes.

The correct Option is "Sodium thiosulphate reacts with iodine to form sodium sulphate."

Which of the following is not correct for the allotropic forms of carbon

Diamond is diamagnetic as there is no unpaired electron.

${C_{60}}$ molecule has a shape like soccer ball and called Buckminster fullerene

Graphite is thermodynamically most stable allotropic form of carbon

Graphite fibres embedded in plastic material form high strength, lightweight composites

The correct Option is "In diamond each carbon atom undergoes $S{P^3}$ hybridisation and is paramagnetic."

Which of the following is not correct?

The unit of electrochemical equivalent (Z) is g/C. $w = Z.i.t$ $\therefore Z = \frac{w}{{i.t}}{\rm{g}}/C$

Aqueous solution of NaCl is an electrolyte.

The correct Option is "The units of electrochemical equivalent are g-coulomb."

In the Nernst equation, n represents the number of electrons transferred in the electrode reaction.

Standard reduction potential of hydrogen electrode is zero volt.

$2{N_2}{O_5}\;\leftrightharpoons\;4N{O_2} + {O_2}$ For the above reaction which of the following is not correct above rates of reaction?

$2{N_2}{O_5}\;\leftrightharpoons\;4N{O_2} + {O_2}$ $Rate = \pm \frac{1}{{\begin{array}{*{20}{c}} {stoichiometrics}\\ {coefficient} \end{array}}}\frac{{d\;product\;or\;reactant}}{{dt}}$ $\therefore Rate = \frac{{ - 1}}{2}\frac{{d\left[ {{N_2}{O_5}} \right]}}{{dt}} = + \frac{1}{4}\frac{{d\left[ {N{O_2}} \right]}}{{dt}} = \frac{{d\left[ {{O_2}} \right]}}{{dt}}$ $Or\; - \frac{{d\left[ {{N_2}{O_5}} \right]}}{{dt}} = 2\frac{{d\left[ {{O_2}} \right]}}{{dt}}$ $Or\;\frac{{ - 2d\left[ {{N_2}{O_5}} \right]}}{{dt}} = 4\frac{{d\left[ {N{O_2}} \right]}}{{dt}}$ $Or\;\frac{{d\left[ {N{O_2}} \right]}}{{dt}} = \frac{{4d\left[ {{O_2}} \right]}}{{dt}}$

$\frac{{ - d\left[ {{N_2}{O_5}} \right]}}{{dt}} = 2\frac{{d\left[ {{O_2}} \right]}}{{dt}}$

$\frac{{ - 2d\left[ {{N_2}{O_5}} \right]}}{{dt}} = \frac{{d\left[ {N{O_2}} \right]}}{{dt}}$

$\frac{{d\left[ {N{O_5}} \right]}}{{dt}} = 4\frac{{d\left[ {{O_2}} \right]}}{{dt}}$

The correct Option is "$\frac{{ - 2d\left[ {{N_2}{O_5}} \right]}}{{dt}} = 4\frac{{d\left[ {N{O_2}} \right]}}{{dt}} = \frac{{d\left[ {{O_2}} \right]}}{{dt}}$"

Which of the following is not correct regarding the ratio telescope

Radio waves can pass through dust, clouds, fog, etc, in a radio, telescope. It can detect very faint radio signal due to enormous size of its reflection. So it can be used at night and even in cloudy weather

The correct Option is "It can not work at night"

It can detect a very faint radio signal

It can be operated even in cloudy weather

It is much cheaper than optical telescope

Which of the following is not correct regarding the electrolytic preparation of ${{\rm{H}}_2}{{\rm{O}}_2}?$

${{\rm{H}}_2}{{\rm{O}}_2}$ can be prepared by electrolysis of ${\rm{50\% }}$ ${{\rm{H}}_2}{\rm{S}}{{\rm{O}}_4}$. In this method, hydrogen is liberated at cathode. ${{\rm{H}}_2}{\rm{S}}{{\rm{O}}_4}\;\leftrightharpoons\;2{{\rm{H}}^ + } + 2{\rm{HSO}}_4^ - $ At anode : $2{\rm{HS}}{{\rm{O}}_4} \to {{\rm{H}}_2}{{\rm{S}}_2}{{\rm{O}}_8} + 2{e^ - }$ ${{\rm{H}}_2}{{\rm{S}}_2}{{\rm{O}}_8} + 2{{\rm{H}}_2}{\rm{O}} \to 2{{\rm{H}}_2}{\rm{S}}{{\rm{O}}_4} + {{\rm{H}}_2}{{\rm{O}}_2}$ At cathode : $2{{\rm{H}}^ + } + 2{e^ - } \to {{\rm{H}}_2} \uparrow $

${\rm{50\% }}\;{{\rm{H}}_2}{\rm{S}}{{\rm{O}}_4}\;$ is used

The correct Option is "Hydrogen is liberated at anode"

Sulphuric acid undergoes oxidation

Which of the following is not correct?

Physical adsorption decreases with increase in temperature, whereas chemisorptions first increase and then decreases with increase in temperature.

Enthalpy of physical adsorption is less compared to enthalpy of chemical adsorption

The correct Option is "Physical adsorption increases with the increase in temperature"

Which of the following is not correct?

Milk is a naturally occurring emulsion

The correct Option is "Gold sol is a lyophilic sol"

Physical adsorption decreases with rise in temperature

Chemical adsorption is unilayered

Which of the following is not correct about carbon monoxide ?

The carboxyhaemoglobin is about ${\rm{300}}$ times more stable than oxyhaemoglobin.

It reduces oxygen carrying ability of blood.

The correct Option is "The carboxyhaemoglobin (haemoglobin bound to ${\rm{CO}}$) is less stable than oxyhaemoglobin."

It is produced due to incomplete combustion.

Which of the following is not correct?

Aniline undergoes diazotisation.

Ethylamine and aniline both have ${\rm{N}}{{\rm{H}}_2}$ group

Ethylamine and aniline both dissolve ${\rm{HCl}}$

Ethylamine and aniline both react with ${\rm{CHC}}{{\rm{l}}_3}$ and ${\rm{KOH}}$ to form unpleasant smell

The correct Option is "Ethylamine and aniline both react with ${\rm{NaN}}{{\rm{O}}_2} + {\rm{HCl}}$ to give hydroxyl compounds in cold"

Which of the following is not correct about transition metals?

Transition metals can form ionic or covalent compounds and their melting and boiling points are high. Their compounds are generally coloured and they usually exhibit variable valency.

Their compounds are generally coloured.

They can form ionic or covalent compounds.

Their melting and boiling points are high.

The correct Option is "They do not exhibit variable valency."

Which of the following is not correct?

The formation of ozone from oxygen is an endothermic reaction not exothermic reaction. $3{O_2}\xrightarrow[{{\rm{discharge}}}]{{{\rm{Electric}}}}2{O_3};\,\,\,\Delta H = 287\,kJ$ So, statement $3{O_2}\xrightarrow[{{\rm{discharge}}}]{{{\rm{Silent}}}}2{O_3};{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} \Delta H = - 284.5\,kJ$ Is not correct statement.

Ozone undergoes addition reaction with unsaturated carbon compounds

Sodium thiosulphate reacts with ${{\rm{I}}_{\rm{2}}}$ to form sodium tetrathionate and sodium iodide.

Ozone oxidises lead sulphide to lead sulphate

Gametogenesis is the formation of

Gametes. The major reproductive events in human beings are as follows (i) Gametogenesis It is the formation of gametes. It includes spermatogenesis (formation of sperms) and oogenesis (formation of ova/eggs) (ii) Insemination It is the transfer of sperms by the male into the genital tract of the female (iii) Fertilization Fusion of male and female gametes to form zygote is called fertilization (iv) Cleavage It is rapid mitotic divisions of the zygote which convert the single celled zygote into a multicellular structure called blastocyst (blastula) (v) Implantation It is the attachment of blastocyst to the uterine wall (vi) Placentation It involves the formation of placenta which is the intimate connection between the foetus and uterine wall of the mother to exchange the materials (vii) Gastrulation It is the process by which blastocyst is changed into gastrula with three primary germ layers (viii) Organogenesis It is the formation of specific tissue, organs and organ systems from three primary germ layers (ix) Parturition (child birth) it involves expelling of the baby from the mother’s womb (uterus)

The correct Option is "Gametes"

Find out the correct statement I. Pills prevents ovulation of contraception technique II. Copper-T prevents implantation III. Vasectomy produces semen containing no sperm

Correct statements are (i) Pills prevent ovulation (ii) Copper-T prevents implantation (iii) Vasectomy causes semen having no sperm

The correct Option is "I and II"

Partial pressure of the gas is the pressure contributed by

Pressure contributed by the individual gas in a mixture of gases is called partial pressure and is represented as $\rho {{\rm{O}}_2}$ for oxygen and $\rho C{{\rm{O}}_2}$ for carbon dioxide

The correct Option is "Individual gas in a mixture"

Pressure exerted by atmosphere on gases

‘Water-vascular’ system is found in

Echinoderms have water-vascular system (ambulacral system) with tube-feet for locomotion, feeding and respiration, e.g., Cucumaria (sea cucumber).

The correct Option is "Sea-cucumber"

One of the characteristic of Hydra is

Hydra is exclusively carnivorous and obtained its food as a predator.

The correct Option is "Predation"

What is the composition of bile?

Bile is secreted by liver and stored in gall bladder. Bile is a watery fluid, having bile salts, bile pigments and sodium bicarbonate, cholesterol, mucin, lecithin fats, etc. It is mixed with the food in intestine along with the pancreatic and intestinal juices

The correct Option is "All of the above"

Injections and implants (the progesterone or progesterone oestrogen combination) are used by the females under the

Six matchstick-sized capsules containing steroids are inserted under the skin of the inner arm above the elbow. These steroid capsules slowly releases the synthetic progesterone for about five years

The correct Option is "Skin of the inner arm above elbow"

How many external rows of ciliated comb plates are usually present in the body of comb jellies?

Ctenophores, commonly known as sea walnuts or comb jellies are exclusively marine and their body bears eight external rows of ciliated comb plates, which help in locomotion.