In Rhizopus, tubular thread-like structures bearing sporangia at their tips are called
Characters transmitted from parents to offspring are present in
Which of the following is the correct sequence of events of sexual reproduction in a flower?
In a flower, the parts that produce male and female gametes (germ cells) are
The growth of pollen tubes towards ovules is due to
The shape of guard cells changes due to change in the
Iodine is necessary for the synthesis of which hormone?
The main function of abscisic acid in plants is to
Which is the correct sequence of the components of a reflex arc?
In a neuron, conversion of electrical signal to a chemical signal occurs at/in
In a synapse, chemical signal is transmitted from
Which is the first enzyme to mix with food in the digestive tract?
The opening and closing of the stomatal pore depends upon
What prevents backflow of blood inside the heart during contraction?
During respiration exchange of gases take place in
Which is the correct sequence of air passage during inhalation?
In which part of the alimentary canal food is finally digested?
Which part of alimentary canal receives bile from the liver?
In which of the following groups of organisms, food material is broken down outside the body and absorbed?
Which is the correct sequence of parts in human alimentary canal?
Which one of the following does not increase while moving down the group of the periodic table?
Arrange the following elements in the order of their increasing nonmetallic character
Li, O, C, Be, F
Arrange the following elements in the order of their decreasing metallic character
Na, Si, Cl, Mg, Al
Which of the following gives the correct increasing order of the atomic radii of O, F and N?
Which one of the following elements exhibit maximum number of valence electrons?
The elements A, B, C, D and E have atomic number 9, 11, 17, 12 and 13 respectively. Which pair of elements belong to the same group?
According to Mendeleev's Periodic Law, the elements were arranged in the periodic table in the order of
Upto which element, the Law of Octaves was found to be applicable
Mineral acids are stronger acids than carboxylic acids because
Select the correct option:
Chlorine reacts with saturated hydrocarbons at room temperature in the
Which of the following are correct structural isomers of butane?
2 mL each of concentrated HCl, HNO3 and a mixture of concentrated HCl and concentrated HNO3 in the ratio of 3 : 1 were taken in test tubes labelled as A, B and C. A small piece of metal was put in each test tube. No change occurred in test tubes A and B but the metal got dissolved in test tube C respectively. The metal could be
If copper is kept open in air, it slowly loses its shining brown surface and gains a green coating. It is due to the formation of
Stainless steel is very useful material for our life. In stainless steel, iron is mixed with
Galvanisation is a method of protecting iron from rusting by coating with a thin layer of