HALF YEARLY EXAMINATION

SUBJECT - BIOLOGY

CLASS- XII

Time: 90 Minutes M.M. : 35

Q1 Genes that code for a pair of contrasting traits are known as

       a) Dominant genes                                b) Alleles

       c) Linked genes                                    d) None of these

Q2 Which of the following characters was not chosen by Mendel?

       a) Pod shape                                           b) Pod colour

       c) Position of flower                            d) Position of pod

Q3 What is the probability of production of dwarf offsprings in a            cross between two heterozygous tall pea plant?

       a) Zero                                                b) 50%

       c) 25%                                                d) 100%

Q4 What will be the distribution of phenotypic features in the first          filial generation after a cross between a homozygous female and       a heterozygous male for a single locus?

       a) 3:1                                                b) 1:2:1

       c) 1:1                                                d) None of these

Q5 The letter T in T-lymphocyte refers to

       a) Thymus                                        b) Thyroid

       c) Thalamus                                    d) Tonsil

Q6 Which of the following is a pair of viral diseases?

       a) Typhoid, Tuberculosis                b) Ringworm, AIDS

       c) Common cold, AIDS                d) Dysentry, common cold

Q7 Blood group agglutinogen is

       a) Glycoprotein                               b) Phosphoprotein

       c) Haemoprotein                            d) Phospholipid

Q8 The vector of the Kala-azar is

       a) Aedes sp                                    b) Anopheles stephensi

       c) Culex fatigens                            d) Phlebotomus sp.

Q9 Diacetyl morphine is commonly known as

       a) Morphine                                b) Cannabis

       c) heroin                                       d) cocaine

       e) hashish

Q10 HIV mainly infects

       a) cytotoxic T-lymphocytes           b) helper lymphocytes

       c) cell-mediated- T-lymphocytes    d) killer lymphocytes

Q11 A cell- coded protein that is formed in response to infection with        most animal viruses is called

       a) interferon                                b) antigen

       c) histone                                    d) antibody

Q12 Heroin is derived from

       a) Papaver somniferum            b) Cannabis indica

       c) Thea chinensis                       d) Erythroxylon coca

Q13 B- cells are stimulated to produce antibodies by

       a) killer cells                        b) suppressor cells

       c) helper cells                        d) none of these

Q14 Type of immunoglobulin present in colostrum is

       a) IgA                                    b) IgG

       c) IgD                                    d) IgE

Q15 Excessive consumption of ethanol causes damage to the liver

       a) liver                                b) kidneys

       c) lungs                                d) heart

Q16 Animals undergo inactive stage during winter is known as

       a) aestivation                    b) hibernation

       c) adaptation                    d) acclimitisation

Q17 The population of an insect species shows an explosive increase        in numbers during rainy season followed by its disappearance at        the end of the season. What does this show??

       a) the food plants mature and die at the end of the rainy season

       b) its population growth curve is of J-type

       c) the population of its predators increase enormously

       d) S- shaped or sigmoid growth of this insect

Q18 Small fish get struck near the bottom of a shark and derives its            nutrition from it? This kind of association is called as

       a) symbiosis                    b) commensalism

       c) predation                    d) parasitism

Q19 The formula for exponential population growth is

       a) dN/dt= rN                    b) dt/dN= rN

       c) dN/rN=dt                       d) rN/dN=dt

Q20 The equation ΔNn/ ΔNt= B represents which of the following?

       a) natality                        b) growth rate

       c) mortality                    d) all of these

Q21 Logo of WWF-N is

       a) Red panda                   b) Giant panda

       c) Polar bear                   d) Tiger

Q22 If the Bengal tiger become extinct

       a) Hyaenas and Wolves will become scarce

       b) The wild areas will be safe for man and domestic animals

       c) its gene pool will be lost for ever

       d) the population of beautiful animals like deers will get                        stabilized

Q23 Extinction of a species in a food chain is compensated by

       a) food chain                b) ecological pyramid

       c) food web                   d) none of these

Q24 The Wildlife Protection Act was introduced in

       a) 1972                        b) 1981

       c) 1986                        d) 1991

Q25 List of endangered species was released by

       a) IUCN                        b) BBC

       c) WCC                        d) UN

Assertion- Reason type Questions

Directions (Q No. 26-30): Each of the following questions consists of two comments one is Assertion (A) and the other is Reason (R). Select the correct answer to these questions from the codes a, b, c and d as given below:

A. Both Assertion and Reason are true and reason is the correct explanation of Assertion.

       B. Both Assertion and Reason are true but reason is not the                    correct explanation of Assertion.

       C. Assertion is true but reason is false.

       D. Both assertion and reason are false.

Q26   Assertion (A): Mendel was successful in his hybridization                experiment.

         Reason (R): garden pea proved to be an ideal experimental                material

Q27 Assertion (A): A pair of contrasting characters is termed as                allele.

       Reason (R): Two alleles of a gene express equality in an                    individual.

Q28 Assertion (A): In some Drosophila, bilateral gynandromorphs            are found.

       Reason (R): The gynandromorphs are formed by an irregularity        in mitosis at the first cleavage of the zygote

Q29 Assertion (A): Turner’s syndrome is caused due to absence of           any one of the X and Y sex chromosome.

       Reason (R): Such individual shows masculine as well as                    feminine development.

Q30 Assertion (A): True breeding lines have stable trait inheritance            fir several generations.

       Reason (R): Mendel conducted cross-pollination experiments            on true breeding lines

Q31 Neutrophils escape from the capillaries

       a) by pushing between endothelial cells

       b) by breaking the capillary wall cells

       c) through pores in the endothelium

       d) by dissolving capillary wall

Q32 LSD is

       a) lysing diethylamide

       b) lysergic acid diethylamide

       c) lysing dimethylamide

       d) lysergic acid dimethylamide

Q33 Stimulant cocaine is obtained from

       a) Rauwolfia                b) Erythroxylon

       c) Papaver                    d) Eucalyptus

Q34 Antiviral substance produced by many vertebrates in response            to viral infection for resisting the multiplication of virus is                known as

       a) virion                        b) interferon

       c) antivirin                    d) antigen

Q35 Antibody production is assisted by

       a) monocytes                b) leucocytes

       c) lymphocytes            d) erythrocytes