2. Assertion and Reason type question.
(a) Assertion : In some animals young ones are different from the adults.
Reason: They undergo direct development.
(b) Assertion : If thyroxine is not released by thyroid gland goitre occurs.
Reason: Thyroid glands bulge out and swells up as thyroxine is not released
Answers
Answer:
Organisms reproduce for perpetuation of species because individuals have a limited life span. Organisms may reproduce sexually as well as asexually. The sexual reproduction involves formation of haploid gametes through the process of reduction division or meiosis. The haploid gametes fuse during fertilization to form diploid zygote. Thus, restoring the normal ploidy. The asexual reproduction does not involves gamete formation through meiosis or their fertilization. The vegetative propagation in plants is a type of asexual reproduction in which plant body is propagated directly from some vegetative part of adult plant.
Therefore, the correct answer is option A.
2)The correct statement is- 'The pineal gland secretes a hormone melatonin which helps to regulate sleep pattern. Parathyroid Gland release hormone which regulates the level of calcium in the blood with the help of calcitonin which is produced in the thyroid gland.'
So the correct option is 'ii and v only'.