ISC Biology Semester-1 Specimen Paper Solved 2022 Class-12 for practice. Step by step solutions of ISC Class-12 specimen model sample paper . During solutions of semester-1 Biology specimen paper we explain with figure , graph, table whenever necessary so that student can achieve their goal in next upcoming exam of council. Visit official website CISCE for detail information about ISC Board Class-12.
.ISC Biology Semester-1 Specimen Paper Solved 2022 Class-12
| Board | ISC |
| Class | 12th (XII) |
| Subject | Biology |
| Topic | Semester-1 ISC Specimen Paper Solved |
| Syllabus | on bifurcated syllabus (after reduction) |
| session | 2021-22 |
| Question Type | MCQ/ Objective (as prescribe by council) |
| Total question |
Total=50 |
| Max mark |
70 |
ISC Biology Semester-1 Specimen Paper Solved 2022 Class-12
Question 1
Which of the following steps in transcription is catalysed by RNA polymerase?
(a) Initiation
(b) Elongation
(c) Termination
(d) All of the above
Answer-
(d) All of the above
Explanation
There is single DNA-dependent RNA polymerase that catalyses transcription of all types of RNA in bacteria. RNA polymerase binds to promoter and initiates transcription (Initiation). It uses nucleoside triphosphates as substrate and polymerises in a template dependent fashion following the rule of complementarity.
Question 2
In a DNA strand the nucleotides are linked together by
(a) glycosidic bonds
(b) phosphodiester bonds
(c) peptide bonds
(d) hydrogen bonds
Answer-
(b) phosphodiester bonds
explanation
Two nucleotides are linked through 3 5 phosphodiester linkage to form a dinucleotide. More nucleotides are joined in a similar manner to form a polynucleotide chain.
Question 3
If the sequence of nitrogen bases of the coding strand of DNA in a transcription unit
is: 5’ – ATGAATG – 3’, the sequence of bases in its RNA transcript would be:
(a) 5’ – AUG A AUG – 3’
(b) 5’ – UACUU AC – 3’
(c) 5’ – CAUUCAU – 3’
(d) 5’ – GUAAGUA – 3’
Answer-
It includes coding and template strands of DNA in which template strand forms the RNA and follows the base pairing rule except for uracil in place of thymine in RNA strand.
Question 4
In E. coli the lac operon gets switched on when
(a) lactose is present and it binds to the repressor
(b) repressor binds to operator
(c) RNA polymerase binds to the operator
(d) lactose is present and it binds to RNA polymerase
Answer-
The repressor protein binds to the operator region of the operon and prevents RNA polymerase from transcribing the operon. In the presence of an inducer, such as lactose or allolactose,
Question 5
(a) 5’- end
(b) 3’ – end
(c) anticodon site
(d) DHU loop
tRNA has anticodon loop that has bases complementary to the code, it also has an amino acid acceptor end by which it binds to amino acids. The site lies at the 3′ end opposite the anticodon in tRNAs are specific for each amino acid
Question 6
Which of the following provides the most satisfactory evidence in the favour of the organic
evolution?
(a) Fossils
(b) Neoteny
(c) Connecting links
(d) None of above
Fossils are the preserved remains or traces of animals, plants, and other organisms from the remote past. Thus, they provides evidence of evolution.
Question 7
Which era is dubbed as the age of prokaryotic microbes?
(a) Phanerozoic
(b) Proterozoic
(c) Precambrian
(d) Archeozoic
Answer-
The geological time scale of life on earth is divided into four major units: Eons, Eras, Periods, and Epochs.
Question 8
The presence of gill slits in the embryos of all vertebrates supports the theory of:
(a) Recapitulation
(b) Organic evolution
(c) Metamorphosis
(d) Biogenesis
Answer–
Explanation
Question 9
(b) Carbon dioxide, hydrogen, water vapour and ammonia
(c) Ammonia, methane, hydrogen and water vapour
(d) Hydrogen, ammonia and methane and helium
Answer-
Miller and Urey provided first proof for chemical synthesis of proteins by amino acids. They simulated the primitive earth conditions as proposed by Oparin and synthesized simple organic compounds (amino acids, fatty acids sugars etc) from a mixture of methane, hydrogen, water vapour and ammonia.
Question 10
Neo–Darwinism is:
(a) Natural selection theory
(b) Modern mutation theory
(c) Modern synthetic theory
(d) Population theory
Answer-
Neo-Darwinism is known as a modern synthetic theory. It is a combined form of the evolutionary theory of natural selection and modern population genetics.
Question 11
Trichoderma, free living fungi, present in root ecosystem are useful as:
(a) Biofertilizer
(b) Biopesticides
(c) Methanogens
(d) Vector for genetic engineering
Answer-
is a genus of fungi. It is used to treat seeds and soils to eliminate pathogens. These species have long been recognized as biological agents to control plant diseases.
Question 12
During spermatogenesis, the second maturation division results in the formation of:
(a) 8 haploid spermatids
(b) 2 diploid spermatids
(c) 4 haploid spermatids
(d) 16 haploid spermatids
Answer
Correct option is (c) 4 haploid spermatids
Explanation
Meiosis begins with a cell called a primary spermatocyte. At the end of the first meiotic division, a haploid cell is produced called a secondary spermatocyte. This haploid cell must go through another meiotic cell division. The cell produced at the end of meiosis is called a spermatid. When it reaches the lumen of the tubule and grows a flagellum (or “tail”), it is called a sperm cell. Four sperm result from each primary spermatocyte that goes through meiosis
Question 13
What is the effect of high pH on sperm?
(a) High activity leading to early death
(b) Sluggish, longer life
(c) High activity, longer life
(d) No effect
Answer
Correct option is (c) High activity, longer life
Explanation
Since pH affects the metabolic rate and the motility of sperm, and consequently alters the vitality of sperm
Question 14
If temperature is reduced to 0°C, what will happen to spermatozoa?
(a) All will die
(b) No change
(c) Shedding of tail
(d) Temporary inactivation
Answer
Correct option is (d) Temporary inactivation
Explanation
Sperms depend on catabolism of fructose for their energy demand. At a temperature of zero degree celsius, the process of respiration stops because respiration is an enzymatic process. This will temporarily inactivate the sperms.
Question 15
Select the incorrect statement about gametes:
(a) Sperm begin developing before puberty
(b) Sperm do not develop successfully at 37°C
(c) Sperm are made in the seminiferous tubules
(d) Sperm are capable of movement
Answer
Correct option is (a) Sperm begin developing before puberty
Explanation
after attaning puberty sperm bigin to develop
Question 16
In industries, citric acid is obtained from which of the following the microbe?
(a) Aspergillus niger
(b) Clostridium botulinum
(c) Saccharomyces cerevisiae
(d) Trichoderma polysporum
Answer
Correct option is (a) Aspergillus niger
Explanation
Question 17
(b) Clearing of fruit juices
(c) Blood cholesterol lowering agents
(d) Meat tenderisers
Answer
Correct option is (c) Blood cholesterol lowering agents
Question 18
Biological name of the common yeast used in baking industry is:
(a) Saccharomyces cerevisiae
(b) Clostridium butylicum
(c) Trichoderma polysporum
(d) Propionibacterium shermanii
Answer
Correct option is (a) Saccharomyces cerevisiae
Explanation
Baker’s yeast is the common name for the strains of yeast commonly used in baking bread and other bakery products, serving as a leavening agent which causes the bread to rise (expand and become lighter and softer) by converting the fermentable sugars present in the dough into carbon dioxide and ethanol. Baker’s yeast is of the species Saccharomyces cerevisiae, and is the same species (but a different strain) as the kind commonly used in alcoholic fermentation, which is called brewer’s yeast. Baker’s yeast is also a single-cell microorganism found on and around the human body.
Question 19
Which of the following microbes is used in the production of Swiss cheese?
(a) Aspergillus niger
(b) Mucor
(c) Monascus purpureus
(d) Penicillium notatum
Answer
Correct option is ……………….
Explanation
Swiss cheese is formed by the bacterium Propionibacterium sharmanii.
Question 20
Which of the following can be used as biofertilizer?
(a) Anabaena
(b) Nostoc
(c) Oscillatoria
(d) All the above
Answer
Correct option is .(d) All the above.
Explanation
Blue-Green Algae are a type of photosynthetic bacteria consisting either of single cells or colonies which is also known as the Cyanobacteria. Cyanobacteria contain only one type of chlorophyll, Chlorophyll a, a green pigment. In addition, they also contain pigments such as carotenoids, phycobilin.
Examples of cyanobacteria: Nostoc, Oscillatoria, Spirulina, Microcystis, Anabaena.
Question 21
The abbreviation ‘HIV’ stands for:
(a) Human immune virus
(b) Hepatitis virus
(c) Human Immuno deficiency virus
(d) Highly infectious virus
Answer
Correct option is .(c) Human Immuno deficiency virus
Question 22
The abbreviation snRNA stands for:
(a) Small nuclear RNA
(b) Small nucleus and RNA
(c) Small nucleolar RNA
(d) Sub-nuclear RNA
Answer
Correct option is (a) Small nuclear RNA
Question 23
The fact that DNA is the genetic material was proved by:
(a) Meselson and Stahl
(b) Sutton and Boveri
(c) Watson and Crick
(d) Hershey and Chase
Answer
Correct option is (d) Hershey and Chase
Question 24
The term biodiversity was coined by:
(a) Wilson
(b) R Mishra
(c) Rio de Janeiro
(d) Oparin
Answer
Correct option is ……………
Explanation
The term biodiversity was coined by Walter G. Rosen in the year 1986.
Question 25
Bt cotton is a/an ______ resistant variety of cotton.
(a) Insecticide
(b) Pest
(c) Insect
(d) Disease
Answer
Correct option is (b) Pest
Explanation
Question 26
Bt cotton has been produced by transferring genes of _____ into the cotton plant.
(a) Escherichia coli
(b) Pseudomonas putida
(c) Bacillus tumorigenes
(d) Bacillus thuringiensis
Answer
Correct option is (d) Bacillus thuringiensis
Explanation
Bt cotton has been genetically modified by the insertion of one or more genes from a common soil bacterium, Bacillus thuringiensis. These genes encode for the production of insecticidal proteins, and thus, genetically transformed plants produce one or more toxins as they grow
Question 27
The enzyme pectinase is obtained from:
(a) Bacillus aureus
(b) Bacillus cereus
(c) Trichoderma
(d) Claviceps
Answer
Correct option is……….
Explanation
Pectinases can be extracted from fungi such as Aspergillus niger. The fungus produces these enzymes to break down the middle lamella in plants so that it can extract nutrients from the plant tissues and insert fungal hyphae.
Question 28
The enzyme ___ is used to remove the turbidity and clear the fruit juices:
(a) Zymase
(b) Pectinase
(c) Amylase
(d) Papain
Answer
Correct option is.(b) Pectinase
Explanation
Question 29
(a) Chemical
(b) biological
(c) mechanical
(d) physical
Answer
Correct option is.(b) biological
Explanation
Question 30
(a) Reproductive
(b) Endocrine
(c) Excretory
(d) All the above
Answer
Correct option is.(b) Endocrine
Explanation
The corpus luteum (CL) is a dynamic endocrine gland within the ovary that plays an integral role in regulation of the menstrual cycle and early pregnancy. The CL forms from cells of the ovarian follicle wall during ovulation. The precise origin of the cells that comprise the CL remains controversial
Question 31
The hormone _(A)__, released by __(B)__ helps in the release of milk from the mammary
glands
(a) Oxytocin, placenta
(b) Prolactin, posterior pituitary
(c) Prolactin, ovary
(d) Oxytocin, posterior pituitary
Answer
Correct option is.(b) Prolactin, posterior pituitary
Explanation
Prolactin (PRL) released from lactotrophs of the anterior pituitary gland in response to the suckling by the offspring is the major hormonal signal responsible for stimulation of milk synthesis in the mammary glands
Question 32
If the mother is homozygous for blood group B, and the father is heterozygous for blood group A, their offspring will be of ___ and ___ blood groups:
(a) A, B
(b) O, B
(c) B, AB
(d) A, AB
Answer
Correct option is.(c) B, AB
Explanation
if father is heterozygous (I I”) and mother is homozygous (I I); the total different types of possible combinations by three alleles (I, I and I) will be (I I and II). But if mother is heterozygous (I I) and father is homozygous (I I); the total different types of possible combinations by three alleles (I, I and I) will be (I I and II).
Question 33
The vermiform appendix is ____ organ in humans.
(a) A homologous
(b) An analogous
(c) A vestigial
(d) An over-specialised
Answer
Correct option is. (c) A vestigial
Explanation
Question 34
The sperm of Drosophila contains _____ number of chromosomes:
(a) 4
(b) 46
(c) 23
(d) 8
Answer
Correct option is. (a) 4
Explanation
In Drosophila melanogaster there are 4 homologous pairs of chromosomes: 2 pairs of large autosomes, ( one slightly smaller than the other pair), 1 pair of very small autosomes, and a pair of sex chromosomes ( X, Y ).
Question 35
(a) It is irreversible
(b) It causes loss of secondary sexual characters in males
(c) It leads to absence of sperm in the semen
(d) This process involves bilateral cutting and ligating of the sperm ducts
Answer
Correct option is. (d) This process involves bilateral cutting and ligating of the sperm ducts
Explanation
Question 36.
Which of the following statements is correct?
(a) Down’s syndrome is caused due to trisomy of 22nd chromosome
(b) Haemophilia is an autosomal recessive disorder
(c) The life on the Earth appeared about 3.5 million years ago
(d) In angiosperms, the endosperm is triploid
Answer
Correct option is. (d) In angiosperms, the endosperm is triploid
Explanation
Most angiosperms have a Polygonum-type embryo sac with two polar nuclei and produce a triploid (3n) endosperm as in Arabidopsis. In a few species, more than two polar nuclei are present in the central cell leading to the formation of endosperm with a ploidy higher than 3n
Question 37
Identify the correct match from the columns and mark the correct option:
……………
(a) A-q-iv, B-p-iii, C-r-ii, D-s-i
(b) A-s-iv, B-p-iii, C-q-ii, D-r-i
(c) A-q-i, B-r-ii, C-s-iii, D-p-iv
(d) A-q-iv, B-r-ii, C-p-i, D-s-iii
Answer
Correct option is. ……
Explanation
Question 38
Match Column – I with Column – II and select the correct option from the choices given below:
………………….
Matching codes:
(a) A-3, B-1, C-2, D-4
(b) A-1, B-4, C-3, D-2
(c) A-2, B-1, C-4, D-43
(d) A-4, B-3, C-2, D-1
Answer
Correct option is. ……
Explanation
Question 39
Which of the following is odd one out with reference to evolution?
(a) Flippers of whale
(b) Wings of pigeon
(c) Forelimbs of rabbit
(d) Wings of butterfly
Answer
Correct option is.(d) Wings of butterfly
Explanation
Wings of butterfly is not originate from pectoral girdle as a) Flippers of whale (b) Wings of pigeon and (c) Forelimbs of rabbit so they are common
Question 40
Which of the following is odd one out with reference to geological time scale?
(a) Proterozoic
(b) Mesozoic
(c) Jurassic
(d) Coenozoic
Answer
Correct option is.(c) Jurassic
Explanation
other than Jurassic rest are geological ERA
Question 41 to 50 available soon
Also visit
- ISC Specimen Paper Semester-1 Solved Class-12
- ISC Class-12 Textbook Solutions, Paper, Notes , Syllabus
- ISC Board Paper Class-12 Solved Previous Year Question
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Hello,it is very helpful.
But , when will you post Q.41 to q.50
Today is our biology exam at 2: 00 a.m. What will we do afterwards??????
please focus on sem-2