HSC Science (General) इयत्ता १२ वी - Maharashtra State Board Question Bank Solutions for Biology

Give the microbial source of Vit. B₁₂

After puberty human female shows cyclic changes in her reproductive system. Explain structural and hormonal changes in the uterus.

                                      (OR)

Give reasons :
(1) Scrotal sac serves as thermoregulator.
(2) Corpus luteum gets converted into corpus albicans in absence of fertilization.
(3) Missing of menses is the first indication of pregnancy.
(4) Surgical sterilization is a permanent method of birth control. (5) Human egg is microlecithal.

Attempt any TWO of the following: 

Define ‘deforestation’. Comment on its effects

The permanent removal of forests and woodlands is called ---------------

From which microbial sources can pectinase be obtained?

Why is zona pellucid retained around the egg till it reaches the uterus?

Erythromycin is obtained from ______.

Suggest measures to conserve the forests. 

Give the names and functions of enzymes involved in lactose metabolism in E. Coli. 

Name the three ossicles of the middle ear.

Long answer question

Draw the neat labelled diagram of the human ear.

The _______ is also called the womb.

What is the source of cocaine? 

Antibiotic Chloromycetin is obtained from ______.

Most commonly used substrate for industrial production of beer is ___________.

Ethanol is commercially produced through a particular species of ______.

MOET technique is used for _____________.

What is the microbial source of vitamin B₁₂?

What is the microbial source of enzyme Invertase?

Name the enzyme produced by Streptococcus bacterium? Explain its importance in medical Science?