NIOS Biology Solved Question Paper October 2021 Set A
1 MARK QUESTIONS
1. Parthenocarpy is:
(A) Production of seeds with pollination and fertilisation
(B) A type of asexual reproduction
(C) Development of plants by micropropagation
(D) Development of fruit from unfertilized ovary
2. Name the group which includes spiny-skinned marine animals which has tube feet for locomotion.
(A) Porifera
(B) Reptilia
(C) Echinodermata
(D) Arthropoda
3. Priya is unable to see in dim light. Lack of which nutrient is she suffering from?
(A) Protein
(B) Vitamin A
(C) Vitamin C
(D) Vitamin B
4. From which part of the plant does guttation take place?
(A) Lenticels
(B) Cuticle
(C) Stomata
(D) Hydathodes
5. Bt. crops are:
(A) Transgenic crops
(B) Hybrid crops
(C) Crops which are pest-resistant
(D) Crops on which Bacillus thuringiensis forms gall
6. Choose an organism which transmits Malaria in humans:
(A) Female culex mosquito
(B) Aedes mosquito
(C) Plasmodium
(D) Female Anopheles
7. __________ is an autosomal disorder.
(A) Down’s syndrome
(B) Turner’s syndrome
(C) Sickle cell anemia
(D) Haemophilia
8. Ginger and Turmeric are examples of:
(A) Tuberous root
(B) Rhizome
(C) Tuber
(D) Sucker
2 MARKS QUESTIONS
9. (a) Name a naturally occurring growth inhibitor found in a wide variety of plants.
(b) Define the term Vernalisation.
Ans:
Abscisic acid
Low temperature treatment, which stimulates early flower formation in some plants, is called vernalisation.
10. Draw a neat diagram of Amoeba and label the following:food vacuole, pseudopodium and contractile vacuole.
Ans:
11. Mention any four activities which help in maintaining sustainable development.
Ans:
Reducing excessive use of resources and enhancing resource conservation.
Recycling and reuse of waste materials.
Scientific management of renewable resources, especially bio-resources.
Planting more trees.
Green grassy patches are to be interspersed between concrete buildings.
Using more environmentally friendly materials or biodegradable materials.
Use of technologies which are environmentally friendly and based on efficient use of resources.
12. Name any two disorders of the musculoskeletal system which are hereditary.
Ans:
Myasthenia gravis is caused by a gene on the X chromosome and so is hereditary. The muscles slowly waste away, and the patient gradually becomes immobile, and in the last stages, even the jaw muscles do not work, and the patient is unable to eat.
Muscular dystrophy is an autosomal dominant disorder. In this hereditary disorder, muscles waste away, and the person becomes immobile.
13. State the four characteristics of the muscle fibres.
Ans: The muscle fibres have the following characteristics:
Excitability (respond to stimulus)
Extensibility (stretch)
Contractility (contract)
Elasticity (move back to the original position)
14. Define the following terms:
(a) Ecotone
(b) Ecological succession
Ans:
An ecotone is a transitional zone between two ecosystems.
The process by which communities of plant and animal species in an area are replaced by another over a period of time is known as ecological succession.
15. Draw a neat and labelled diagram of a stomatal apparatus of a dicot leaf.
Ans:
16. (a) Give an example each of broad-spectrum antibiotics and narrow-spectrum antibiotics.
(b) State any two drawbacks of using antibiotics.
Ans: a)
Broad-spectrum antibiotic: Chloramphenicol
Narrow-spectrum antibiotic: Penicillin
b) Drawbacks of using antibiotics
Some people are allergic to a particular antibiotic.
Some disease-causing bacteria undergo mutation and become resistant to a particular antibiotic to which they were sensitive earlier.
17. Briefly explain double fertilisation in Angiosperms.
Ans: One sperm fuses with the egg (syngamy) and forms a diploid zygote. The other sperm fuses with the secondary nucleus to form the primary endosperm nucleus, which is triploid in nature. Since two types of fusion, syngamy and triple fusion, take place in an embryo sac, the process is termed double fertilisation.
18. Distinguish between in situ and Ex-situ conservation of Biodiversity.
Ans:
In-situ (on-site conservation includes the protection of plants and animals within their natural habitats or in protected areas. Protected areas are areas of land or sea dedicated to the protection and maintenance of biodiversity. For example: e.g., National Parks, Wildlife Sanctuaries, Biosphere Reserves, etc.
Ex-situ (off-site) conservation is the conservation of plants and animals outside their natural habitats. These include Botanical Gardens, Zoo, Gene Banks, DNA Banks, Seed Banks, Pollen Banks, Seedling and Tissue Culture, etc.
19. Distinguish between chondrichthyes and osteichthyes with suitable examples.
Ans:
Chondrichthyes
Osteichthyes
Mouth ventral
Mouth terminal
Tail heterocercal
Tail homocercal
Skeleton cartilaginous
Skeleton bony
Five to seven pairs of gills
Four pairs of gills
Operculum (gill cover) absent
Operculum present
Example: Scoliodon (dog-fish)
Example: Labeo (Rohu)
20. List any four adaptations found in Anemophilous flowers.
Ans: Adaptations of anemophilous flowers,
Flowers are small, without colour, nectar and scent.
Flowers produce a large number of pollen grains to allow for wastage when pollen grains are carried by wind to another flower.
The pollen grains are small, light and sometimes provided with ‘Wings’.
The stigmas are comparatively large, protruding and sometimes hairy, to trap pollen grains from wind, for example, grasses and some cacti.
4 MARKS QUESTIONS
21. (a) Draw a neat diagram of the Excretory organs in humans and label the following parts:
Kidney, Ureter and Urethra
(b) Name the structural and functional units of the kidney.
Ans:
Excretory organs in humans
Structural and functional unit of the kidney: Nephrons
22. (a) List any four reasons for population explosion in India.
(b) State and define the surgical methods of family planning in human males and females.
Ans:
Reasons for the population explosion in India
Advancement in agriculture
Advancement in medicine
Religious and social customs
Industrialization
Surgical methods of family planning.
Vasectomy in males, where the vas deferens is ligated (tied) by the surgeon to prevent sperm from going out of the body.
Tubectomy in females, where the fallopian tubes are cut and ligated to prevent the ovulated egg from passing down for fertilisation.
23. (a) Draw a neat and labelled diagrammatic structure of an Antibody.
(b) Distinguish between an antigen and an antibody.
Ans:
Antibody
An antigen is any foreign molecule that can trigger a specific immune response. An antibody is a protein molecule produced in animals in response to an antigen.
24. How do Archaebacteria differ from Eubacteria? State the three types of Archaebacteria
and also mention the location they are found.
Ans: Archaebacteria include bacteria that live in unusual environments, particularly at low levels of oxygen. Eubacteria include all other bacteria, excluding cyanobacteria.
The main types of Archaebacteria are
Methanogenic bacteria that live in sewage and the intestinal tracts of animals
Thermoacidophilic bacteria that live in hot springs.
Halophilic bacteria live in salty conditions where the hot sun concentrates seawater.
25. (a) What is Hydroponics? Give any two significance of this process.
(b) Give the scientific name of any one Insectivorous plant.
Ans:
The technique of growing plants in a nutrient solution in the complete absence of soil is known as Hydroponics/water culture. It helps us to understand :
Which element is essential for the normal growth of the plant.
Which element is not essential and is absorbed along with other nutrients.
How much quantity of each mineral is essential.
Insectivorous plant: Nepenthes (Pitcher plant)
26. (a) Draw a neat diagram of the double helical structure of DNA.
(b) Who proposed this structure?
Ans:
Double helical structure of DNA
Franklin and Wilkins
6 MARKS QUESTIONS
27. (a) List any four functions of proteins in our diet.
(b) Expand the abbreviation PEM. Name the two diseases caused due to PEM.
(c) What do you understand by Hypervitaminosis? Name the two vitamins and their effect on the human body when taken regularly.
Ans:
Functions of proteins (any four)
Proteins are required for building and maintaining body tissues.
Proteins are found in all the enzymes e.g. Trypsin, pepsin and rennin.
Some proteins function as hormones to regulate many body functions. For example, insulin is a hormone which regulates blood glucose levels in the body.
Proteins also act as antibodies and protect the body from antigens (foreign agents).
Transport protein carries different substances from the blood to the tissues in the body. Haemoglobin is a transport protein.
PEM: Protein Energy Malnutrition. Eg, Marasmus and Kwashiorkor.
The disease caused by the presence of vitamins in excessive quantities in the body is called hypervitaminosis. Two vitamins whose deficiency causes hypervitaminosis are
Vitamin A accumulates in the liver, causing loss of hair, drowsiness, painful swelling in the legs, etc.
Vitamin D in excess leads to high calcium absorption in the intestine, which leads to calcium deposition in the kidneys, nausea, drowsiness, etc.
28. (a) Give the generalized balanced equation to show the process of Photosynthesis.
(b) Expand the abbreviations:
(i) Rubisco
(ii) PEPco and explain the role of these enzymes. Where are these enzymes present in the C4 plants?
(c) What do you understand by Compensation point?
Ans:
Photosynthesis
Expand:
Rubisco: Ribulose Bisphosphate Carboxylase/oxygenase. Rubisco is a part of the C3 cycle and combines with CO2 to produce a C3 compound called PGA.
PEPco: PEP carboxylase. PEPCo is a part of the C4 pathway and combines with CO2 to form a C4 compound called OAA.
At a certain light intensity, the amount of CO2 used in photosynthesis and the amount of CO2 produced in respiration are the same. This point of light intensity is known as the compensation point.
29. Briefly state two contrasting features each in sex-determination in humans, birds and in honey bees?
Ans:
Sex determination in humans
In humans, males are heterogametic and females are homogametic
Males produce XY sex chromosomes while females produce XX.
Sex determination in birds
In birds, females are heteromorphic and males are homomorphic.
Females produce A+Z and A+W gametes. Males produce only A+Z gametes.
Sex determination in honey bees
Fertilised eggs produce females, and unfertilised eggs become males.
Females are diploid and males are haploid.
30. (a) Draw a neat and labelled diagram of the internal structure of the human ear.
(b) Briefly explain the mechanism of hearing.
Ans:
Human ear
Mechanism of hearing
The sound waves enter the auditory canal and cause the eardrum to vibrate.
The vibrations of the eardrum are transferred to the malleus, to the incus, and then to the stapes. Stapes transfers the vibrations through the oval window into the cochlea.
These vibrations move the fluid in the cochlea. The organ of Corti catches the movement of the fluid and transfers it to the auditory nerve that carries the impulses to the brain.