By QB365 on 23 Apr, 2021
12th Standard Biology English Medium Reproduction Organisms Important Questions
12th Standard
Biology
Part - A
In each of the following questions there are two statements. One is assertion (A) and other is reasoning (R). Mark the correct answer as
Assertion (A) : In bee society, all the members are diploid except drones.
Reason (R) : Drones are produced by parthenogenesis
Codes:
A. If both A and R are true and R is correct explanation for A
B. If both A and R are true but R is not the correct explanation for A
C. If A is true but R is false
D. If both A and R are false.
If both A and R are true and R is correct explanation for A
If both A and R are true but R is not the correct explanation for A
If A is true but R is false
If both A and R are false
Assertion and reasoning questions:
In each of the following questions there are two statements. One is assertion (A) and other is reasoning (R). Mark the correct answer as
Assertion: Viviparous animals give better protection to their off springs.
Reason: They lay their eggs in the safe places of the environment.
Codes:
A. If both A and R are true and R is correct explanation for A
B. If both A and R are true but R is not the correct explanation for A
C. If A is true but R is false
D. If both A and R are false.
If both A and R are true and R is correct explanation for A
If both A and R are true but R is not the correct explanation for A
If A is true but R is false
If both A and R are false
Conjugation is seen in _____
Vorticella
Amoeba
Reptiles
Actinosphaerium
Starfish shown ______ type of regeneration.
epimorphosis - reparative
epimorphosis (restorative)
morphallaxis
paedogenesis
Transverse binary fission is noticed in _________________
Amoeba
Planaria
Ceratium
Vorticella
The site of embryo implantation is the _____.
Uterus
Peritoneal cavity
Vagina
Fallopian tube
Assertion(A): In human male, testes are extra abdominal and lie in scrotal sacs.
Reason(R): Scrotum acts as thermoregulator and keeps temperature lower by 2oC for normal sperm production.
Codes:
(a) A and R are true, R is the correct explanation of A
(b) A and R are true, R is not the correct explanation of A
(c) A is true, R is false
(d) Both A and R are false
A and R are true, R is the correct explanation of A
A and R are true, R is not the correct explanation of A
A is true, R is false
Both A and R are false
_____ is a temporary endocine gland formed during pregnancy from the follicle.
oestrogen
corpus luteum
progesterone
relaxin
The stage where the embryo looks like a fluid filled hollow ball is called ______
trophoblast
morula
gastrula
blastocyst
Statement (1): Human pregnancy lasts for 35 weeks.
Statement (2): During gestation, embryo's heat develops during 12th week
Statement 1 is correct; statement 2 is incorrect
Statement 1 is incorrect; statement 2 is correct
Both the statements 1 and 2 are correct
Both the statements 1 and 2 are correct
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.
Match column I with column II and select the correct option from the codes given below.
Column I | Column II |
A. Copper releasing IUD | (i) LNG-20 |
B. Hormone releasing | (ii) Lippes loop IUD |
C. Non medicated IUD | (iii) Saheli |
D. Mini pills | (iv) Multiload-375 |
A | B | C | D |
(iv) | (ii) | (i) | (iii) |
A | B | C | D |
(iv) | (i) | (iii) | (ii) |
A | B | C | D |
(i) | (iv) | (ii) | (iii) |
A | B | C | D |
(iv) | (i) | (ii) | (iii) |
One of the following prevents sperm from heading off to penis as the discharge has no sperms in it.
Tubectomy
LNG - 20
Vasectomy
Cu T 380 Ag
Prevention of children from sexual offences is covered under ______ act
PCPNDT
patent act
ART
POCSO
In chorionic villus sampling test, the tissue sample is taken from _________
amniotic fluid
placental tissue
Intestinal villi
foetal liver
Down's syndrome is a genetic disorder which is caused by the presence of an extra chromosome number _____.
20
21
4
23
Which of the following is incorrect regarding ZW-ZZ type of sex determination?
It occurs in birds and some reptiles
Females are homogametic and males are heterogametic
Male produce one type of gamete
It occurs in gypsy moth
__________ is a disease where abnormal haemoglobin is produced in patients.
Phenylketonuria
Huntington's chorea
Thalassemia
Albinism
One gene 'L' controlling blood groups is named after_________.
c. B. Bridges
Henking
Landsteiner
Stevens
The fruit fly Drosophila melanogaster was found to be very suitable for experimental verification of chromosomal theory of inheritance by Morgan and his colleagues because
It reproduces parthenogenetically
A single mating produces two young flies
Smaller female is easily recognizable from largemale
It completes the life cycle in about two weeks
Which of the following is the correct sequence of event with reference to the central dogma?
Transcription, Translation, Replication
Transcription, Replication, Translation
Duplication, Translation, Transcription
Replication, Transcription, Translation
Which of the following statements is not true about DNA replication in eukaryotes?
Replication begins at a single origin of replication.
Replication is bidirectional from the origins.
Replication occurs at about 1 million base pairs per minute
There are numerous different bacterial chromosomes, with replication occuring in each at the same time.
Escherichia coli fully labeled with N14 medium. The two strands of DNA molecules of the first generation bacteria have
Different density and do not resemble parent DNA
Different density but resemble parent DNA
Same density and resemble parent DNA
Same density but do not resemble parents DNA
Whose experiment finally provided convincing evidence that DNA is the genetic material?
Griffith experiment
Avery, Macleod and McCarty's experiment
Hershey-Chase experiment
Urey-Miller's experiment
Which one of the following is wrongly matched?
Transcription - Copying information from DNA to RNA
Translation - Decoding information from mRNA to protein
Replication - Making of DNA copies
Splicing - Joining of exons with introns
The wings of birds and butterflies is an example of
Adaptive radiation
convergent evolution
divergent evolution
variation
Which period was called “Age of fishes”?
Permian
Triassic
Devonian
Ordovician
Emergence of modern birds occurred in _____________ period.
Devonian
Silurian
Jurassic
Cretaceous
All the following provided the energy for chemical reaction in the primitive earth Except:
Rain
Lightning
UV radiations
volcanic activity
Darwin's finches in Galapagos islands and Australian Marsupials are the example of
Industrial mechanism
Reproductive isolation
Genetic recombination
Adaptive recombination
Exo-erythrocytic schizogony of Plasmodium takes place in _______
RBC
Leucocytes
Stomach
Liver
Spread of cancerous cells to distant sites is termed as
Metastasis
Oncogenes
Proto-oncogenes
Malignant neoplasm
___________is a genetic disease
Rickets
Cystic fibrosis
Tuberculosi
Candidiasis
________________ test is done to confirm typhoid.
ELISA
Western blot
Widal test
Southern blot
Which one of the following pairs is wrong.
Amoebiasis - Home fly
African sleeping sickness - Tsetse flies
Kala-azar - Sand fly
Malaria - female Anopheles mosquito
Cry toxins obtained from Bacillus thuringiensis are effective against for______
Mosquitoes
Flies
Nematodes
Bollworms
Cyclosporin – A is an immunosuppressive drug produced from _______
Aspergillus niger
Manascus purpureus
Penicillium notatum
Trichoderma polysporum
Lactobacillus helps to produce________
Citric acid
Milk
Acetic acid
Butyric acid
The cry toxin affects_______system of insect pests
Nervous system
Respiratory system
Digestive system
Reproductive system
Select the correct statement from the following
Primary treatment of sewage involves biological oxidation
Excreta of cattle is commonly called Gobur
Delta endotoxin of Bacillus thuringiensis is encoded by pen-genes
Trichoderma is a free-timing bacteria very common in root ecosystem
How many amino acids are arranged in the two chains of Insulin
Chain A has 12 and Chain B has 13
Chain A has 21 and Chain B has 30 amino acids
Chain A has 20 and Chain B has 30 amino acids
Chain A has 12 and chain B has 20 amino acids.
Which one of the following statements is true regarding DNA polymerase used in PCR?
It is used to ligate introduced DNA in recipient cells
It serves as a selectable marker
It is isolated from a Virus
It remains active at a high temperature
_________is not linked to IPR.
Patents
Copy rights
GI
trademarks
All the following are recombinant vaccines. Except
Traditional vaccines
Submit recombinant vaccines
Attenuated recombinant vaccines
DNA vaccines
__________is an example for DNA vaccine
MMR
Hepatitis B
BCG
oral polio
The relationship between sucker fish and shark is__________
Competition
Commensalism
Predation
Parasitism.
What type of human population is represented by the following age pyramid?
Vanishing population
Stable population
Declining population
Expanding population
Van't Hoffs rule describes the impact of ____________ on the environment.
Light
Temperature
Water
Soil
Type of response in hibernation and aestivation.
Suspend
Regulate
Migrate
Conform
Pick out the eurythermal organism
Fish
Frog
Tiger
Lizards
Select the correct linear equation describing the species - area relationship.
loc C = log S + Z log A
Z 10gA= log S + log C
log S = log C + Z log A
log C = log S ± Z log A
Tilapia fish (Oreochromis mossambicus) is exotic breed from_______
Mexico
South Africa
Canada
Central America
Right to Clean Water is a fundamental right, under the Indian Constitution
Article 12
Article 21
Article 31
Article 41
Which among the following awards instituted by the Government of India for individuals or communities from rural areas that have shown extraordinary courage and dedication in protecting Wildlife?
Indira Gandhi Paryavaran Puraskar
Medini Puruskar Yojana
Amrita Devi Bishnoi Award
Pitambar Pant National Award
Average human consumption of oxygen per day is_________
280 L
550 L
620 L
730 L
The intensity of noise is measured in_______
Dobson
Hertz
Decibel
Frequency
According to noise pollution rules 2000, the permissible level of noise in commercial area is ________ during day and ________during night
55 db, 65 db
65 db, 55 db
70 db, 60 db
75 db, 65 db
Part - B
Define isogamy.
During which stagesidoes multiple fission occur is plasmodium.
How is polyspermy avoided in humans?
Draw a labeled sketch of a spermatozoan.
Describe the location and shape of the uterus.
Define the terms
(a) Insemination
(b) Fertilization.
Define Tubectomy and Vascetomy.
Name any four national level health care programmes run by Indian Government
What is haplodiploidy?
What is Lyonisation?
What is Lyon's hypothesis?
Comment on Trisomy-21.
Give reasons: ‘Genetic code is universal’.
Mention any two ways in which single nucleotide polymorphism (SNPs) identified in human genome can bring revolutionary change in biological and medical science.
What is TATA box? State its function
Mention the inhibitory role of tetracycline and streptomycin in bacterial translation
Name the types of natural selection.
Write a brief note on Homo sapiens with respect to evolution.
Name two RNA viruses which cause diseases in humans.
What causes shivering in malarial patient?
What is "clot buster"?
The first antibiotic was extracted from fungus. Who had done it? And also mention the fungal species used.
Name the disease that are treated by using interferons.
Define the terms (a) Totipotency (b) Unipotency
StateIordon's rule.
What is ecosphere?
Name any four biogeographic zones in India.
Mention any two species that had become extinct very recently.
Define the term eutrophication.
Complete the following:
(a) Smoke +_____ = Smog
Part - C
Why is the offspring formed by asexual reproduction referred as a clone?
Give the definition for (a) Arrhenotoky (b) Thelytoky (c) Amphitoky
Mention the importance of the position of the testes in humans.
Menstrual hygiene is essential for women. Why?
Expand the following
a) ZIFT
b) ICSI
How LNG-20 act as contraceptive?
What is male heterogamety?
What is the chemical reaction that is affected in people suffering from Albinism?
Distinguish between structural gene, regulatory gene and operator gene
What is 'Wobbling' in tRNA?
Taking the example of Peppered moth, explain the action of natural selection. What do you call the above phenomenon?
What are coprolites? Mention its role in phylogeny.(or) Write a short note on Coprolites.
Name the diseases for which vaccines were developed by Louis Pasteur
How do statins help to control cholesterol levels?
Explain how ADA deficiency can be corrected
State any two uniqueness of ELISA test.
People leaving in high altitudes show increased RBC count. Give reason.
Why do we find a decrease in biodiversity distribution, if we move from the tropics towards the poles?
Give examples of any three National Parks in Tamil Nadu.
Write a brief note on Chipko movement.
Part - D
Write notes on binary fission in animals.
Describe the structure of human ovary.
What is ART? Explain any two for ART.
Discuss the methods adopted for the improvement of human race.
How the DNA is packed in an eukaryotic cell?
Explain the events in life cycle of plasmodium in the secondary host/Man
How microbes are used in Gobar gas production?
Explain in detail about stem cell therapy. (or) What are the multipotent cells involved in replenishing adult tissue ? What is the rich source for it?
Explain structural and behavioural adaptations seen in organism.
Write a note on extinction and its types
How radioactive waste are managed? Suggest few methods of disposal of radioactive waste.(or) write an essay on Radioactive waste management.