Question

Give the biological technical terms for the following.
(i) Chemical found in the blood which act against antigens
(ii) A constituent that causes pollution
(iii) The onset of menstruation in a young girl
(iv) Structure which connects the placenta with the foetus
(v) The fluid present between the layers of meninges
(vi) Permanently open structures seen on the bark of an old woody stem
(vii) The biological process which is the starting point of the food chain
(viii) The change in an organism resulting due to stimulus
(ix) An Antiseptic substance present in tears
(x) A solution in which the relative concentration of water molecules and the solute on either side of the cell membrane is the same

Answer 1

(i) Immunoglobulin (Ig) are glycoprotein molecules that are produced by plasma cells which functions as antibodies and act against antigens.

(ii) Any substance that pollutes anything, water or atmosphere is called as pollutant.

(iii) The first occurrence or onset of menstruation in a young girl is called as menarch.

(iv) Umbilical cord is found in placental mammals. It is the connecting link between the developing embryo or fetus and the placenta which helps in exchange of gas between fetus and mother, transpotation of food etc.

(v) Cerebrospinal fluid is a clear watery fluid which fills the space between the layers of meninges. It absorbs the shock and prevents the brain from mechanical injury.

(vi) Lenticels are lens shaped openings in big woody trunks of trees for gaseous exchange.

(vii) Photosynthesis is the starting point of food chain. By the process of photosynthesis, autotrophs prepare their food which is then transferred to the food chain via herbivorous.

(viii) Reflex action is an involuntary and nearly instantaneous movement or change in an organism in response to a stimulus.

(ix) Lysozymes are present in a number of secretions, such as tears, saliva, human milk and mucus. They act as antiseptic substance by breaking down bacterial cell walls.

(x) Isotonic solution is a solution which has same osmotic pressure on either side of cell membrane.