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Published on: 05/11/2020
12th Standard Biology English Medium Free Online Test One Mark Questions with Answer Key 2020 - Part Nine
Download Tamil Nadu 12th Standard Biology question papers, model tests, one-mark questions, important questions, and public exam papers in PDF format. Free study materials and answer keys for TN State Board students.
Questions + Answers key
Take MCQ Biology Test1.
Corn \(\overset { A }{ \rightarrow } \) Fermentable sugars \(\overset { B }{ \rightarrow } \) Ethanol. Find out A and B for above statement.
A - Agaricus, B - Sarcina
A - Zymomonas, B - Vinegar
A - Rhizopus, B - Aspergillus
A - Aspergillus, B - Yeast
2.
Identify the incorrect statement
Water is a universal solvent
Water has less surface tension
Water is heavier than air
When freezes water contracts
3.
Average human consumption of oxygen per day is_________
280 L
550 L
620 L
730 L
4.
Select the proper sequence indicating the increasing order of biodiversity.
Polar, Temperate and Polar
Tropics, Temperate and Polar
Temperate, Tropic and Polar
Polar, Tropic and Temperate
5.
Self-ligation is prevented by____________
DNA Polymerase
Helicase
Alkaline phosphate
DNA lipase
6.
At which stage of meiosis, does the chromosomes undergo recombination process
Leptotene stage of prophase I
Zygotene stage of prophase I
Diplotene stage of prophase I
Pachytene stage of prophase I
7.
Assertion (A): Test cross is done between F2 hybrid with F1 recessive
Reason (R): It helps to identify the homozygosity of hybrids
A and R are correct R explains A
A and R are incorrect
A is correct R is incorrect
A is incorrect R is correct
8.
Assertion (A): Carica papaya is a dioecious plant.
Reason (R): Both male and female flowers are borne on same plant.
A is correct R is incorrect.
R explains A.
Both A and R are incorrect.
Both A and R are correct. R does not explain A.
9.
Identify the incorrect statement
Carbon stored in oil is referred as Grey carbon
Carbon stored in atmosphere is referred as Blue carbon
Carbon stored in industrialized forests is referred as Green carbon
Carbon emitted from gas, died engine is referred as Black carbon
10.
The term green revolution was coined by ___________
William S Gaud
M.S. Swaminathan
Dr. B.P. Pal
Dr. N.E. Borla
11.
Which is not a true statement regarding rainwater harvesting?
Mitigates groundwater quality
Reduces soil erosion
Decreases soil salinity
No wastage of land for storing
12.
Identify the Tamil name for flaked rice
Nel
Aval
Pori
Umi
13.
According to Darwin, the organic evolution is due to
Intraspecific competition
Interspecific competition
Competition within closely related species.
Reduced feeding efficiency in one species due to the presence of interfering species.
14.
Bacillus thuringiensis forms protein crystals which contain insecticidal protein. This protein
Binds with epithelial cells of midgut of the insect pest ultimately killing it.
Is coded by several genes including the gene cry.
Is activated by acid pH of the foregut of the insect pest.
Does not kill the carrier bacterium which is itself resistant to this toxin.
15.
The unit for measuring ozone thickness _____.
Joule
Kilos
Dobson
Watt
16.
Which of the following is correct for r-selected species
Large number of progeny with small size
large number of progeny with large size
small number of progeny with small size
small number of progeny with large size
17.
Which of the following plant has a non-succulent xerophytic and thick leathery leaves with waxy coating
Bryophyllum
Ruscus
Nerium
Calotropis
18.
The Hydrochlorofluorocarbons (HCFCs) are the compounds which have the following molecules:
Hydrogen
Carbon
Chlorine
Fluorine
19.
Transgenic animals are those which have
Foreign DNA in some of their cells
Foreign DNA in all their cells
Foreign RNA in some of their cells
Foreign RNA in all their cells
20.
A contraceptive pill prevents ovulation by ______.
blocking fallopian tube
inhibiting release of FSH and LH
stimulating release of FSH and LH
causing immediate degeneration of released ovum.
21.
Which of the following statements about DNA replication is not correct?
Unwinding of DNA molecule occurs as hydrogen bonds break.
Replication occurs as each base is paired with another exactly like it
Process is known as semi conservative replication because one old strand is conserved in the new molecule.
Complementary base pairs are held together with hydrogen bonds
22.
The milk secreted by the mammary glands soon after child birth is called ______.
Mucous
Colostrum
Lactose
Sucrose
23.
AIDS virus has
Single stranded RNA
Double stranded RNA
Single stranded DNA
Double stranded DNA
24.
Which of the following is true about Rh factor in the offspring of a parental combination DdxDd (both Rh positive)?
All will be Rh-positive
Half will be Rh positive
About ¾ will be Rh negative
About one fourth will be Rh negative
25.
Test cross involves ____.
Crossing between two genotypes with recessive trait
Crossing between two F1 hybrids
Crossing the F1 hybrid with a double recessive genotype
Crossing between two genotypes with dominant trait
1.
(d)
A - Aspergillus, B - Yeast
2.
(b)
Water has less surface tension
3.
(b)
550 L
4.
(a)
Polar, Temperate and Polar
5.
(c)
Alkaline phosphate
6.
(d)
Pachytene stage of prophase I
7.
(b)
A and R are incorrect
8.
(a)
A is correct R is incorrect.
9.
(c)
Carbon stored in industrialized forests is referred as Green carbon
10.
(a)
William S Gaud
11.
(a)
Mitigates groundwater quality
12.
(b)
Aval
13.
(b)
Interspecific competition
14.
(a)
Binds with epithelial cells of midgut of the insect pest ultimately killing it.
15.
(c)
Dobson
16.
(a)
Large number of progeny with small size
17.
(c)
Nerium
18.
(c)
Chlorine
19.
(b)
Foreign DNA in all their cells
20.
(b)
inhibiting release of FSH and LH
21.
(b)
Replication occurs as each base is paired with another exactly like it
22.
(b)
Colostrum
23.
(a)
Single stranded RNA
24.
(d)
About one fourth will be Rh negative
25.
(c)
Crossing the F1 hybrid with a double recessive genotype
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Tamilnadu Stateboard 12th Standard Subjects
Maths
Chemistry
Physics
Biology
Computer Science
Business Maths and Statistics
Economics
Commerce
Accountancy
History
Computer Applications
Biology
Computer Technology
Computer Applications
Computer Science
Business Maths and Statistics
Commerce
Economics
Maths
Chemistry
Physics
Computer Technology
History
Accountancy
Tamil
English
French
Tamilnadu Stateboard Standards
