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 Bihar Board 12th Biology Model Question Paper 5 in English Medium

Bihar Board 12th Biology Model Question Paper 5 in English Medium

Time : 3 Hours 15 Min
Total Marks : 70

Instructions for the candidates:

1. Candidates are required to give answers in their own words as far as practicable.
2. Figures in the right-hand margin indicate full marks.
3. While answering the questions, the candidate should adhere to the word limit as for as practicable.
4. 15 Minutes of extra time has been allotted for the candidates to read the questions carefully.
5. This question paper is divided into two sections: Section – A and Section – B
6. In Section – A, there are 35 objective type questions which are compulsory, each carrying 1 mark. Darken the circle with blue/black ball pen against the correct option on OMR Sheet provided to you. Do not use Whitener/Liquid/ Blade/Nail on OMR Sheet otherwise result will be treated as invalid.
7. In Section – B, there are Non-objective type questions. There are 18 Short answer type questions, out of which any 10 questions are to be answered. Each question carries 2 marks. Apart from this, there are 6 long answer type questions, out of which any 3 of them are to be answered. Each question carries 5 marks
8. Use of any electronic device is prohibited.

Objective Type Questions

There are 1 to 35 objective type questions with 4 options. Choose the correct option which is to be answered on OMR Sheet. (35 x 1 = 35)

Question 1.
Pollination by birds is called
(a) Entomophily
(b) Cheiropterophily
(c) Ornithophily
(d) All of the above
Answer:
(c) Ornithophily

Question 2.
Which one is the hotspot of biodiversity?
(a) Eastern Ghat
(b) Western Ghat
(c) Aravalli Hills
(d) None of the above
Answer:
(b) Western Ghat

Question 3.
Who is considered as Father of Genetics?
(a) Morgan
(b) Darwin
(e) Hugo-de-Vries
(d) Mendel
Answer:
(d) Mendel

Question 4.
Noise pollution is measured in
(a) Heartz
(b) Fathoms
(c) Decibels
(d) Nanometer
Answer:
(c) Decibels

Question 5.
Indicator of water pollution is
(a) Entamoeba histolytica
(b) E. Coli
(c) Vibrio cholera
(d) All of the above
Answer:
(b) E. Coli

Question 6.
mRNA formation takes place in
(a) Ribosome
(b) Nucleus
(c) Cytoplasm
(d) Mitochondria
Answer:
(b) Nucleus

Question 7.
Cancer affecting connective tissue is called
(a) Lymphoma
(b) Sarcoma
(c) Carcinoma
(d) None of the above
Answer:
(b) Sarcoma

Question 8.
IgM antibody is found in
(a) Serum
(b) Saliva
(c) Blood
(d) All of the above
Answer:
(c) Blood

Question 9.
How many Peptide chains are found in each antibody molecule?
(a) 4
(b) 3
(c) 2
(d) None of the above
Answer:
(a) 4

Question 10.
Green plants are known as producers, which convert
(a) Chemical energy into light energy.
(b) Light energy into chemical energy
(c) All of the above
(d) None of the above
Answer:
(b) Light energy into chemical energy

Question 11.
Which of the following cry gene prevents crop from borer
(a) Cry AC
(b) Cry / Ab
(c) Cry // Ab
(d) All of the above
Answer:
(d) All of the above

Question 12.
Human blood groups are
(a) A, B, AB, O
(b) A, B, C, O
(c) B, C, O
(d) None of the above
Answer:
(a) A, B, AB, O

Question 13.
Khorana got Nobel prize for
(a) Discovery of RNA
(b) Discovery of DNA
(c) Chemical synthesis of gene
(d) None ‘
Answer:
(c) Chemical synthesis of gene

Question 14.
Secondary pollutant is
(a) CO
(b) C02
(c) PAN
(d) None of these
Answer:
(c) PAN

Question 15.
Chipko movement is launched for protection of
(a) Grass land
(b) Forest
(c) Animal Community
(d) All of the above
Answer:
(b) Forest

Question 16.
TTxttis
(a) Test cross
(b) Back cross
(c) Hybridization
(d) None of the above
Answer:
(a) Test cross

Question 17.
How many types of DNA polymerases are associated with eukaryotic cell ?
(a) 2
(b) 3
(c) 4
(d) 5
Answer:
(d) 5

Question 18.
Example of In Situ conservation is
(a) Zoological garden
(b) Botanical garden
(c) Biological safari park
(d) All of the above
Answer:
(d) All of the above

Question 19.
Which of the following is diploid ?
(a) Male gamete
(b) Ovum
(c) Zygote
(d) All of the above
Answer:
(c) Zygote

Question 20.
Pattern of any population depends on
(a) Density
(b) Distribution
(c) Specific structure
(d) All of the above
Answer:
(d) All of the above

Question 21.
Montreal Protocol is related to control the deleterious effect of
(a) Acid rain
(b) Ozone depletion
(c) Deforestation
(d) Global warming
Answer:
(b) Ozone depletion

Question 22.
Fertilization takes place in
(a) Ovary
(b) Uterus
(c) Fallopian tube
(d) All of the above
Answer:
(c) Fallopian tube

Question 23.
Hugo de-Vries worked on which plant ?
(a) Pea
(b) Evening Primrose
(c) Both
(d) None
Answer:
(b) Evening Primrose

Question 24.
Salmonella is associated with
(a) Polio
(b) T.B,
(c) Typhoid
(d) All of the above
Answer:
(c) Typhoid

Question 25.
AIDS is identified first of all in
(a) USA
(b) France
(c) Russia
(d) All of the above
Answer:
(a) USA

Question 26.
Bones of fore limbs of Bat, and humans are
(a) Homologous
(b) Analogous
(c) Both
(d) None
Answer:
(a) Homologous

Question 27.
Which enzyme is used to join cut ends of DNA?
(a) Ligase
(b) Cellulose
(c) Pectinase
(d) None of the above
Answer:
(a) Ligase

Question 28.
Which of the following serve as biofertilizer in paddy fields?
(a) Yeast
(b) Bacteria
(c) Cyano bacteria
(d) Fungi
Answer:
(c) Cyano bacteria

Question 29.
Which of the following is used in preparing Cheese?
(a) Viruses
(b) Algae
(c) Fungi
(d) Micorobes
Answer:
(d) Micorobes

Question 30.
Statins used for lowering blood cholesterol level
are extracted from
(a) Yeast
(b) Algae
(c) Virus
(d) All of the above
Answer:
(a) Yeast

Question 31.
Microbes are found in
(a) air
(b) water
(c) soil
(d) All of the above
Answer:
(d) All of the above

Question 32.
Ranikhet disease is connected with
(a) Pigs
(b) Cow
(c) Fish
(d) Hens
Answer:
(d) Hens

Question 33.
Induced breeding is done in case of
(a) Apiculture
(b) Pisci culture
(c) Lac culture
(d) Sericulture
Answer:
(b) Pisci culture

Question 34.
Taichung Native-1 is a variety of
(a) Rice
(b) Wheat
(c) Maize
(d) None
Answer:
(a) Rice

Question 35.
Zeba cattle is
(a) Goat
(b) Cat
(c) Cow
(d) Sheep
Answer:
(c) Cow

Non-Objective Type Questions

Short Answer Type Questions

In this section, there are 18 short answer type question (each carryies 2 marks) out of which answers any ten (10) questions. (10 x 2 = 20)

Question 1.
What is co-dominance? Explain with example.
Answer:
In co-dominance both dominant alleles of a gene express themselves equally in F, hybrids. The phenotype ratio matches with genotypic ratio i.e, 1: 2: 1 in F2 generation of offspring. Example of co-dominance can be seen in goat colour in

Question 2.
What is significance of double fertilization?
Answer:
Significance of double fertilization:
(i) Double fertilization is very important in angiospermic plants. If only syngamy occurs in plants and triple fusion does not occur, only 3 zygote will be formed. Endosperm will not be formed and this will result seed with undeveloped embryo or seed without embryo.

(ii) Endosperm is formed due to double fertilization. This provides nutrition to embryo and it contains maternal and paternal chromosomes. A body shows physiological aggressiveness due to hybrid vigour in inner endospermic cells.

Question 3.
What is radio-active pollution? What are the sources of radio-active pollution?
Answer:
Radio-active Pollution: Certain elements such as Radium, Thorium, Uranium emit protons (Alpha particles), electrons (Beta particles) and Gamma particles by disintegration of atomic nuclei. This phenomenon is called radio-activity and these elements are known as radio-active. When the radio-active radiations contaminate to water, air, soil and food materials it is called radio-active pollution.

Question 4.
Define Commensalism and Parasitism.
Answer:
Commensalism: An interaction between two species in which one is benefitted and the other one is neither harmed nor benefitted.
e.g. Orchids growing on trunk/branch of a tree.

Parasitism: An interaction between two species where parasite not only obtains food from its host but also completes its life cycle on the host. e.g. Bacteria, Fungi etc.

Question 5.
What are the ways for controlling amoebiosis?
Answer:
Amoebiosis is caused by a protozoan parasite Entamoeba histolytica, in which pain in stomach and stool with mucus and blood are seen as specific symptom.
Following are the control major of amoebiosis:

1. Patient should take rest and after some interval electrolytic fluid must be taken.
2. For control of disease, emetin, vioform, chinoform and diodoquin should be taken as drug and antibiotics like Terramycine, Erythromycine, Metronidazole and Aureomycin may be helpful in treatment and control of this disease.

Question 6.
What is Jumping Gene (Transposons)?
Answer:
These are capable of changing their locations from one place to another, so it is called jumping genes. It is a mobile fragment of DNA that can change position in a genome, a cause of sequence insertions and deletions in some organisms.

Question 7.
Name four living fossils.
Answer:
A living fossil is a living animal of ancient origin with many primitive characters. A living fossil has been living as such from the time of origin without many changes.
Examples are:

• Peripatus of phylum Arthropoda.
• Limulus of phylum Arthropoda.
• Latimeria-a bony fish.
• Sphenodon-a reptile.

Question 8.
Write any four benefits of micro-propagation.
Answer:
Benefits of micro-propagation:

• By such method crop production increases.
• By such method storage of germplasm can be taken place.
• By Meristem tip culture method disease resistant plants are produced.
• Micropropagation is also beneficial in conservation of biodiversity.

Question 9.
What is fishery? Name few common freshwater and marine edible fishes.
Answer:
Fishery: It is an industry concerned with catching, processing or selling of fish, shell fish or other aquatic animals.
Freshwater edible fishes:

• Catla
• Rohu
• Cirrhina mrigala.

Marine water edible fishes: (a) Hilsa (b) Sardines (c) Mackerel (d) Pomfrets.

Question 10.
Write short notes on gene cloning.
Answer:
The production of living structures genetically identical to their parent structure is known as gene cloning. It is therefore an exact copy of a single living parent. Gene cloning is the act of making copies of single gene. Once a gene is identified clones can be used.

Question 11.
Why is the Human Genome Project called a megaproject?
Answer:
Human Genome Project is called a mega project because it is aimed to sequence every base in human genome. It has developed the ways of mapping the human genome at increasing fine level of precision and to store this information in database and develops tools for data analysis. The magnitude and the requirements for this project are more for opening up new areas and avenues.

Question 12.
What are the functions of t-RNA in the protein synthesis?
Answer:

1. It carries specific amino acids from the cytoplasm to the ribosomal sites for the formation of polypeptide chain according with the sequence specified by m-RNA.
2. The t-RNA charged with the amino acid serves as a adaptor molecule to decode the information on the m- RNA.
3. It comes to elongate the polypeptide chain by the addition of several newly synthesised amino acids.

Question 13.
Define homologous orgAnswer: Give examples.
Answer:
These are the organs of similar structure and origin but dissimilar in functions and form.This is due to common ancestary.
Examples:
(i) The forelimbs of a frog, the wings of a bird, legs of a horse, the hands of a man and the flipper of a whale are homologous organs because all of them have similar pattern of basic plan (pentadacty) i.e. same number of bones, muscles, nerves and blood vessels etc. but they do the different functions such as hopping (frog), flying (bird), running (horse), graping (man) and swimming (whale).

(ii) Phylloclade of Opuntia and Cladode of Ruscus are homologous organs as both are modified stems. Similarly, a thorn of Bougainvillea and a tendril of Cucurbita are homologous as both arise in axillary position.

Question 14.
What is green revolution? List two factors that have led green revolution in India.
Answer: Green revolution is the enormous increase in the food production due to intensive cultivation by use of improved varieties of seeds and fertilizers.
The factors that contributed to the green revolution in India are:

• The development and introduction of high yielding varieties of crop and extension of the high yielding varieties over large area in the country.
• Transfer of technology of scientific farming from research farm to village farmers.

Question 15.
What do you understand by restriction enzyme?
Answer:
Restriction enzymes: These enzymes are nucleases which cut DNA into short pieces containing identifiable genes at specific sites. These pieces are then introduced into plastids, yeasts or plant cells.
Ex. ECORI, Hind-III.

Question 16.
Write short notes on plasmids.
Answer:
A plasmid is small circular double stranded DNA molecule that is distinct from a cell, chromosomal DNA.
Plasmids naturally exist in bacterial cells and they also occur in some eukaryotes. Often, the genes carried in plasmid provide bacteria with genetic advantage, such as antibiotic resistance.

Question 17.
Write short notes on organic evolution.
Answer:
The process by which changes in the genetic composition of populations of organism occur in response to environmental changes is known as organic evolution. Examples of organic evolution include organs that are different in structure but perform similar function. A Dolphin’s flipper’ and human arms are example of organic evolution.

Question 18.
Discuss the concept of IPM.
Answer:
Integrated Pest Management (IPM) aims at minimum use of pesticides to prevent agro-chemical pollution and to adopt natural methods of pest control as far as possible. The natural methods of pest control are the part of a larger agricultural strategy and these include:

1. Use of resistant varieties of crop to local pests.
2. To carry the practice of crop rotation and improved sanitation method.
3. To adopt biological control method and starvation method.
4. To grow planting or a preferred target crop to lure away insects.
5. Use of sterilization strategy, mechanical control, repellents, chemical attractants and natural insecticides etc.

Long Answer Type Questions

There are 6 long answers type question (each carrying 05 marks) out of which answers any three questions. (5 x 3 = 15)

Question 19.
Discuss the characters chosen by Mendel in garden pea. Mention the advantages of selecting this plant for experiment.
Answer:
Gregor Mendel, conducted hybridisation experiments on garden peas for seven years (1856-1863) and proposed the laws of inheritance. During Mendel’s investigations into inheritance patterns it was for the first time that statistical analysis and mathematical logic were applied to problems in biology. His experiments had a large sampling size, which have greater credibility to the data

that he collected. Also, the confirmation of his inferences from experiments on successive generations of his test plants, proved that his results pointed to general rules of inheritance rather than being unsubstantiated ideas. Mendel selected only pea plants for his experiment due to presence of many types of contrasting characters like:

• Round and wrinkled seeds
• Yellow and green seeds
• Violet and white flowers
• Inflated and constricted pods
• Green and yellow pods
• Axillary and terminal flowers
• Tall and dwarf plants

Mendel investigated characters in the garden pea plants that were manifested as two opposite traits which allowed him to set up a basic frame work of rules governing inheritance. Mendel conducted such artificial pollination/ cross pollination experiments using several true breeding pea lines.

Advantages of selecting pea plants for experiment by Mendel:

1. Due to short height of pea plants, it was easy to do experiment on that.
2. Pea plants had a short life cycle so that results could be had within a year.
3. Pea plants produced many seeds in one generation which helped in drawing correct conclusions.
4. Artificial cross-pollination could be easily achieved because androecium and gynoecium were completely enclosed.
5. Pea plants having each of the seven characters he selected were readily available.
6. Mendel took only one character at one time for his experiment.
7. Pea plants are self pollinated and pure.

Question 20.
Give an accout of Neo-Darwinism/Modern concept of evolution.
Answer:
Neo-Darwinism is the improvement of Darwin’s orginal theory of Natural Selection in order to remove its defects.
Important mechanisms for Neo-Darwinism are:
(a) Variations (b) Natural selection (c) Isolation

(a) Variations: Variations which influence evolution are the ones that develop in the genetic machinery of the germ cells. They are formed due to Mutations, Recombinations, Migrations, Hybridisation and Genetic Drift.

(b) Natural Selection: It operates through differential reproduction. Individuals with advantageous variations survives, reach maturity and leave there genes in the gene pool through differential reproduction. Repeated reproductive selection of individuals with specific traits increases the frequency of their genes in the gene pool. Individuals with harmful neutral variations are eliminated at various stages.

(c) Isolation: It is the separation of a segment of population from the rest due to apearance of a barrier. Gene pool of the isolated population changes due to genetic drift and accumulation of different types of reproduction.

Question 21.
Give a labelled diagram of the electron microscopic view of a human sperm and describe it briefly.
Answer:
The human sperm is a microscopic, long, flagellated and haploid motile cell and is formed of head, neck, middle piece and tail.

(i) Head: It constitutes the anterior region of sperm containing nucleus and acrosome. The nucleus is a narrow, flat and oval structure consisting of densely packed nuclear chromatin material. The latter is formed of DNA and nucleo protein. A small pointed sheathy acrosome is found at the anterior region of head and is derived from the golgi bodies. It contains hydrolytic enzyme-hyalourinidase which helps the sperm to penetrate into ovum during fertilization by dispersing the cells of corona radiata.

(ii) Neck: It is very short or indistinguishable region lying in between head and middle piece. It contains the proximal and distal centriole with 9 + 0 arrangement of micro-tubules. The proximal centriole forms the spindle in the first cleavage divison of the fertilised ovum. The distal centriole gives rise to many fine micro-tubules which run upto sperm tail by passing through middle piece.

(iii) Middle piece: It is a cylindrical region lying behind the neck. It contains number of mitochondrial spiral (nebenkern) which encircles the axial fdament arising from distal centriole. The mitochondrial spiral contains the oxidative enzymes which provide energy for movement of sperm by the process called oxidative phosphorylations.

(iv) Tail: It is the longest part of the sperm and is formed of main central axial filament and the outer protoplasmic sheath with small amount of cytoplasm. At the posterior end of tail, the axial filament is naked without any sheath and is called as end piece. The tail undulates rapidly and provides mobility to the sperm with the head forward in the fluid medium.

Question 22.
What is deforestation? Write its causes and effects.
Answer:
Deforestation is the conversion of forest areas to non-forest ones. It is a serious threat to the quality of life, national economy and future of environment. According to an estimate, almost 40>percent forests have been lost in the tropics, compared to only one percent in the temperate region. The present-scenario of deforestation is particularly grim in India.

The main cause of decrease in forest cover in India is deforestation due to expansion of agriculture, urbanization, industrialization, excessive commercial use of timber, fuel, wood etc. The causes of deforestation are population explosion, fires, pests, grazing and gnawing mammals, weather, jhum cultivation, etc.

Effects of deforestation are as follows:

1. Soil erosion has increased;
2. Flood and droughts have become more frequent;
3. Pattern of rain fall is changing;
4. Land slides and avalanches are on the increase;
5. Climate has become warmer;
6. Forest dwilling species are becoming extinct;
7. Consumption of CO2 and production of O2 are getting adversely affected.

Question 23.
Give an account of Apiculture.
Answer:
The maintenance of hives of honey bees for the production of honey is called bee keeping or apiculture.
Bee keeping is a small scale industry for the production of honey which have following economic importance:

• Bee keeping gives honey which is an important nutritive substance.
• Bee-hives gives bee-wax which is utilized in making polishes.
• Bee keeping helps in pollination of various crops useful for mankind

Question 24.
Write short notes on Homology and Analogy organ, vestigial organ, Atavism and Connecting links.
Answer:
(i) Homology and Analogy: The organs of similar structure and origin but dissimilar in functions and forms are called as homologous organs and this phenomenon is called homology. The presence of homologous organs implies a common evolutionary origin of amphibians, reptiles, birds and mammals from some ancient fish ancestor. The homologous structures seen in successive generations indicate actual relationship and the possessors are the diverse descendants of common ancestry (Divergent evolution).

The organs that perform the same function but differ in their origin and structure, are called as analogous organs and the phenomenon is called analogy. The wings of an insect are analogous to those of birds and bats because they perform the same function but have dissimilar structure and origin. The wings of an insect are modified outgrowth of the body wall whereas wings of birds and bats are forelimbs.

These organs have arisen in evolutionary process through adaptation of quite different organisms to a similar mode of life (Convergent evolution). On the same line, the similarities in proteins are genes performing a given function among diverse organisms give clues to common ancestry. These biochemical similarities point to the same shared ancestry as structural similiarities among diverse organisms.

(ii) Vestigial organs: These are the reduced and functionless organs which are of no use to the possessor but they still persists generation after generation in reduced form in an individual. They were complete and functional in the ancestors e.g. appendix in man is considered as the remnant of large intestine (caecum) but it is considered to be storage organ for cellulose digestion in herbivorous mammals. The vestigial organs which used to perform a normal function in the ancestor but during the course of evolution, they have been reduced to vestiges.

(iii) Atavism: It is reappearance of ancestral characters other than parents in the newly born offspring, which have either completely disappeared or reduced. The reappearance of short tail in some babies, multiple mammals in some individuals and dense hairy body etc. are the examples of atavism. The reappearance of such ancestral characters favour evolution.

(iv) Connecting links: The organisms which possess the characters of two different groups of organisms are known as connecting links e.g., duckbilled platypus and spiny ant-eater serve as a connecting link between the mammals and reptiles. Similarly lung fishes (Protopterus) is a connecting link between fishes and amphibians.

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