Biology 2017-2018 HSC Science (General) 12th Standard Board Exam Question Paper Solution

The phenotypic ratio of incomplete dominance is ______.

2 : 1

1 : 2 : 1

1 : 1 : 1

1 : 1 : 2

9 : 3 : 3 : 1

1 : 1

3 : 1

Nucleoside is a nucleotide without________.

(A) Sugar

(B) Nitrogen base

(C) Hydrogen bond

(D) Phosphate group

Which of the following is white button mushroom?

(A) Agaricus bisporus

(B) Pleurotus Florida

(C) Volvariella volvacea

(D) Candida species

Brown rust of wheat is caused by ______.

viruses

bacteria

fungi

aphids

The reaction centre of P.S. II is ________.

(A) Chl-a, 700

(B) Chl-a, 680

(C) Chl-a, 673

(D) Chl-a, 650

The enzymes required for synthesis of ATP are located on

(A) oxysomes

(B) cristae

(C) matrix

(D) ribosomes

In a food chain, the herbivores are represented by

(A) producers

(B) primary consumers

(C) secondary consumers

(D) decomposers

What is leaching?

Define chemoautotrophs.

Name the cell organelle in which Krebs’ cycle occurs.

What is deforestation?

Give the microbial source of Vit. B₁₂

What is primary treatment of sewage?

Sketch and label a pollen grain of angiosperms.

Enlist the basic steps involved in recombinant DNA technology

Give two examples of microbial pesticides with their hosts.

Give the significance of respiration

Explain energy pyramid

Describe the structure of a nucleosome.

Describe the steps of PCR technique.

Describe different steps involved in tissue culture technique

Sketch and label T. S. of a leaf showing Kranz anatomy.

With the help of a neat and labelled diagram, describe the development of the female gametophyte of angiosperms.

Explain the law of independent assortment with a suitable example.

_________ is used for desalination of brackish water.

Reverse osmosis

Ion – exchange

Adsorption

Electrodialysis

Which of the following is mesodermal is the origin?

Retina

Enamel of teeth

Heart

Liver

______ is an exotic breed of cow

(A) Gir

(B) Sindhi

(C) Sahiwal

(D) Jersy

_______ maintains basic metabolic rate.

(A) Thyroxine

(B) ADH

(C) GH

(D) Oxytocin

Which of the following is an example of ZW – ZZ type of mechanism of sex determination?

Honeybee

Fish

Bird

Human being

Transfer of gene between the population that differ genetically from one another is called _____.

(A) Gene mutation

(B) Gene flow

(C) Genetic drift

(D) Genetic recombination

In the given diagram of vaccine manufacturing process ‘A’ is ____________.

Antigen

Antibody

Antitoxin

Antibiotics

Longer toes and long prehensile tail indicate which adaptation?

What does IUCD indicate?

Name of the valve between the left atrium and left ventricle and give its significance.

Give the use of bovine growth hormone

State any two symptoms of Down’s syndrome.

Distinguish between ape and man.

Sketch and label structure of Antibody

Name the causative organism and preventive measures for Typhoid

Draw Diagram of the causative organism of typhoid (Salmonella typhi)

State the economic importance of lac culture.

All organisms produce more young ones. Comment

Describe agranulocytes with the help of diagrams.

Define the following term and give one example:

Parasitism

Describe the structure of chromosomes with a suitable diagram.

Define ‘genomics’. Give any ‘two’ applications of it.

Sketch and label the structure of Malpighian body.

Describe the T.S. of human testis

Write a note on human sperm

Draw labelled diagrams of the following: Eye

Describe the anatomy of the human eye.

Explain the mechanism of vision.