Science [2 Mark Questions]

No, the position of a star as seen by us is not its true position that is the apparent position. The stars appear slightly higher than the actual position because the light coming from the stars suffers refractions due to different layers of atmosphere which is due to different refractive indices value. It seems as if stars are slightly higher than they actually appear.

The characteristics of energy transfer in biosphere are :
i. The ultimate source of energy is sun and is converted from one form to another.
ii. Energy gets continuously transferred through food chain and energy flow is unidirectional.
iii. There is loss of some energy during transfer from one trophic level to the next.
iv. Only 10% of energy is transferred from one trophic level to the next. The solar energy trapped by producers does not revert
back to the sun.
v. At each trophic level, some of the energy is utilized by organisms, rest is lost to environment and only 10% is available to the
next trophic level.

The phenomenon of progressive increase in concentration of certain harmful non-biodegradable chemicals such as DDT at
different levels of food chain is called biological magnifications.
The concentration of harmful chemicals will be different at different trophic levels as the amount of such substances go on
increasing progressively at each trophic level. It will be lowest in the first trophic level and highest in the last trophic level of the
food chain.

i. The lens is a converging lens.
ii. Such an image is obtained in a magnifying glass and in a lens to correct hypermetropia defect of eye.
iii. The image is virtual, erect and enlarged and is formed behind the concave mirror.

There are five steps in the process of nutrition inHuman beings.
1. Ingestion: The process of taking food into the body is called ingestion.Humans have holozoic mode of nutrition.They engulf
solid particles
2. Digestion: the process in which the food containing large, insoluble molecules is broken down into small, water soluble
molecules is called digestion.
3. Absorption: The process in which the digested food passes through the intestinal wall into blood stream is called absorption.
4. Assimilation: The process in which the absorbed food is taken in by the body cells and used for energy, growth and repair is
called assimilation.
5. Egestion: The process in which the undigested food is removed from the body is called egestion.

i. Sperms are produced in seminiferous tubules present in testers of male reproductive system by process known as
spermatogenesis.
ii. Sperm consists of 2 main parts head and tail, both of which are connected by neck. The long tail also known as flagellum of
sperms helps in quick movement or motility of sperms through the female reproductive tract through wave like motion
iii. Sperms are delivered from the site of their production by vas deferens, also known as sperm duct to the urethra in order to
allow the passage of semen outside the body. Movement of sperm is facilitated by prostatic fluid.

Ethanoic acid :