Question

1. Find the mass of an ice cube of edge 2 cm. The density of ice
is 900kg /m^3​

Answer 1

Answer:

All children will inherit an X chromosome from their mother regardless

of whether they are boys or girls. Thus, the sex of the children will be

determined by what they inherit from their father. A child who inherits

an X chromosome from her father will be a girl, and one who inherits a

Y chromosome from him will be a boy.

28 Use of Plastic cups raised the concern towards hygiene thus they were

replaced by disposable plastic cups.

Plastic cups are non-biodegradable and harm the environment friendly.

They were thus replaced by Kulhads.

Making Kulhad made of clay on a large scale resulted in the loss of top

fertile soil.

Now, disposable paper cups are used because - the paper can be

recycled, it is biodegradable and is eco-friendly material which does not

cause environmental pollution.

3

29 - Blood passes through filtration units in the kidney called nephron

- Passes through glomerulus in the Bowman's capsule - Ultra

filtration

- Filtrate initially has glucose, amino acids, water, salts and

nitrogenous waste

- Reabsorption – Water (as per the need of the body), Glucose and

amino acids are all reabsorbed –

- Secretion of excess water, salts and urea (nitrogenous waste)

which makes up the urine

3

30

a. Heating of lead nitrate; and electrolysis of acidified water

b.

Sunlight

2AgCl(s) 2Ag(s) + Cl2 (g)

(No deduction for not mentioning state of reactants and products.)

2

1

31 (i) D, As it is on the left side of the table in group 2

(ii) C, as it is in the group 18/ Noble gas

(iii) E, as we move from left to right across a period, atomic radius

decreases