January 27, 2015

Senior Inter Botany Imp Questions - Mineral Nutrition Chapter

Q: How do you categorize a particular essential element as a macro or
micronutrient?
A: The essential elements present in planet tissues in large amounts
(i.e., more than 10 m mole / Kg-1 of dry matter) are called
macronutrients. Those present in plant tissues in very small amounts
(i.e. less than 10 m mole / Kg-1 of dry matter) are called
micronutrients or trace elements.

Q: Give two examples of essential elements that act as activators for enzymes.
A: Essential elements activate or inhibit enzymes. Some examples for
essential elements
that act as activators for enzymes are
1) Mg2+- Ribulose bisphosphate carboxylase - Oxygenase
2) Zn2+ - Alcohol dehydrogenase
3) Mn2+ - IAA oxidase
4) Mo - Nitrogenase

Q: Name the essential mineral elements that play an important role in
photolysis of water.
A: Calcium (macronutrient), Manganese and chlorine (micronutrients)
play essential role in photolysis (or splitting) of water during light
reaction leading to the evolution of Oxygen.

Q: Out of the 17 essential elements which elements are called
non-mineral essential elements? Name the amino acids in which Sulphur
is present.
A: Among the 17 essential elements Carbon, Hydrogen and Oxygen are
non- mineral macro essential elements. They are obsorbed from CO2 and
H2O. Methionine and cysteine (amino acids) contain Sulphur.

Q: When is an essential element said to be deficient?
A: The concentration of the essential element below which plant growth
in retarded is termed as critical concentration. An essential element
is said to be deficient when present below the critical concentration.

Q: Name two elements whose symptoms of deficiency first appear in
younger leaves.
A: Deficiency symptoms first appear in younger leaves whenever the
elements are relatively immobile. Ex: Sulphur and calcium.

Q: Explain the role of the pink colour pigment in the root nodule of
legume plants. What is it called?
A: Pink colour pigment in the root nodule of the legume plants in
called Leguminous haemoglobin or leg haemoglobin. It protects
nitrogenase from Oxygen as the enzyme is sensitive to Oxygen. Thus it
acts as Oxygen scavenger.

Q: Name the essential elements present in nitrogenase enzyme. What
type of essential elements are they?
A: The essential elements present in the nitrogenase enzyme are Fe and
Mo, Both are micro mineral elements.

10th Physical Sciences Imp Questions - Human Eye - New Syllabus

In morning and evening times except red light all colours scatter more
and vanish before they reach our eye. Since scatering of red light is
very small, it reaches us. So sun appears red in colour during sun
rise and sun set.

Q: How do you appreciate the working of ciliary muscle in the eye? (4 Marks)

A: The ciliary muscle to which eye lens is attached helps the eye lens
to change its focal length by changing the radii of curvature of the
eye lens.

When the eye is focussed on a distant object, the ciliary muscles are
relaxed so that the focal length of the eye lens has its maximum value
which is equal to its distance from the retina. The parallel rays
coming into the eye are then focussed on to the retina and we see the
object clearly. When the eye is focussed on a closer object, the
ciliary muscles are strained and focal length of eye-lens decreases.

The ciliary muscles adjust the focal length in such a way that the
image is formed on retina and we see the object clearly. This process
of adjusting focal length is called "accommodation". This is a
wonderful arrangement the nature provided in the eye. If this is not
provided we would not have lead the present comfortable life with
regard to our vision.

Q: Explain briefly the reason for the blue of the sky. (2 Marks)

A: When we look at the sky in a direction perpendicular to the
direction of the Sun rays the sky appears blue. If our angle of view
is changed, the intensity of blue colour also changes. Molecules of N2
and O2 are the causes for the blue colour of the sky.

The sizes of these molecules are comparable to the wavelength of blue
colour light. So these molecules act as scattering centres for the
blue colour of light. So the sky appears blue.

Q: How can you correct the defect 'hypermetropia'? (2 Marks)

A: Eye lens can form a clear-image on the retina when any object is
placed beyond near point. To correct the defect of hypermetropia, we
need to use a lens which forms an image of an object beyond near
point, when the object is better near point and least distance of
distinct vision. This is possible only when a double convex lens is
used.

Q: Explain the basic process in scattering of light. (1 Mark)

A: Scattering of light is a complex phenomenon. Atoms or molecules
which are exposed to light absorb light energy and emit some part of
the light energy in different directions. This is the basic process
happens in scattering of light.

Junior Inter Zoology - Essay Question from Ecology and Environment

Q: Give an account of energy flow in ecosystem.
A: Except for the deep sea ecosystem, sun is the only source of energy
for all ecosystems on earth. Of the incident solar radiation, less
than 50% of it is photosynthetically active radiation. The producers
(i.e., green plants) fix the solar energy to synthesise food materials
from CO2 and H2O. They trap 2 to 10% of PAR and it sustains the entire
living world.

The heterotrophs depend on producers for their food either directly or
indirectly. The first law of thermodynamics (law of conservation of
energy) states that energy is neither created nor destroyed, but is
transformed from one form to another. Thus the solar energy that is
traped by the producers is converted into chemical energy. Further,
ecosystems also follow the second law of thermodynamics, which states
that no process involving energy transformation will spontaneously
occur unless there is degradation of energy.

As per this law energy dispersed is in the form of unavailable heat
energy, and constitutes the entropy. The organisms need a constant
supply of energy to synthesise molecules they need. The transfer of
energy through a food chain from one trophic level to the next is
called energy flow. The amount of energy available decreases at
successive trophic levels.

When organism dies, the energy in it becomes source of energy for
decomposers. According to 10% law (proposed by Lindeman), during the
transfer of energy from one trophic level to the next, only about 10%
of the energy is stored. The remaining is lost during transfer. The
energy transfer in a food chain can be illustrated as shown below.