Question

1) Fill in the blank :
(a) Deficiency of _________ hormone causes goitre.
(b) The role of microtubule in cell division is formation of __________
(c) In a heterozygote, the gene that can not express _______ is gene.
(d) In an experiment of genetic cross of pure black hair guinea-pig and that of pure white hair, all F1, offsprings appear black. This phenomenon is called ____________ .
(e) An example of vestigial organ in plant is ________ .
(f) One of the commonest effect of cigarette smoking is __________.​

Answer 1

Answer:

a) thyroid

b)mitotic spindle

c)allele

d)heterozygous

e)cassia occidentalis, the androecium

f)cancer

Answer 2

1. Deficiency of Thyroid hormone causes Goitre.
2. In Cell-Division, Micro-tubules are responsible for the formation of 'Mitotic Spindle.' It helps in the Migration of duplicated Chromosomes during Anaphase.
3. In a Heterozygote, the gene that can not express Dominant Traits is a Recessive gene.
4. In an experiment of genetic cross of pure black hair guinea-pig and that of pure white hair, all F1, offsprings appear black. This phenomenon is called 'Law of Dominance' where one type of gene is Dominant over the other. Here, black-hair is a Dominant trait over white-hair.
5. An example of vestigial organ in plant is Gynoecium. Abortive Stamen (Stamen without Anther) is also Vestigial. Vestigial Organs are non-functional and are simple a residual part from their past ancestors.
6. One of the commonest effect of cigarette smoking is Chronic Obstructive Pulmonary Disease (COPD). However, Smoking also causes Cancer, Heart-attack, Lung-disease, Diabetes and Chronic Bronchitis.