Answer: B) Adrenaline Explanation: Heparin is a hormone secreted by the liver. This is anticoagulant in its property. It prevents cloting of blood inside the heart and blood vessels. Heart attack is the result of a block in the blood vessels supplying blood to the walls of the heart.

Answer: C) iodine Explanation: Goitre is characterized by the swelling of the neck region. This is due to the enlargement of the thyroid gland which secretes hormone thyroxine. Thyroxine has iodine as an integral part of it. If there is not sufficient iodine in one's  diet, the thyroid gland swells up.

Answer: A) addition of cells Explanation: Plants grow in size both in height and in grith. Enlargement  of cells already present cannot contribute much to the growth. Only addition of more and more cells could increase the size of the plant considerably.

Answer: A) once Explanation: Plants are of different types. Some grow well and then produce fruits before they die. In other words they fruit only once in their life. Such plants are said to be monocarpic. Other plants produce fruits every season. These are called polycarpic plants.

Answer: C) a perennial herb Explanation: Plantain plant is a herb, because it does not have an aerial stem - what appears as a stem is really the leaves with sheathing bases. As the piant lives for several years it is called perennial herb

Answer: B) within the fruit Explanation: Vivipary means germination even when attached to the mother plant. Usually the saline marsh plants (Halophytes) have their seeds growing even when they are inside the fruits attached to the tree.

Answer: D) Nucleotides Explanation: Genes: The DNA is the genetic material. The DNA is made of several nucleotides. A nucleotide means, one nitrogenous base one sugar molecule and a phosphate molecule. These Nucleotides occur in sequences and several nucleotides form one gene ( a functional gene is called a cistron)

Answer: D) one pest by another Explanation: Biological Control: This method is very effective. One pest is destroyed by another organism. For example the aphids are killed by lady beetle. The prickly pear is eradicted by cochineal insect. Here the advantage is, one does not use harmful chemicals which may get into the host plants.