General Science – Biology MCQs | Important Questions for UPSC, SSC & Govt Exams

General Science – Biology MCQs

Q 1.Skin works as a respiratory organ in which of the following Animals ?
A. Cockroach
B. Frog
C. Whale
D. Dog Fish

Answer: Correct Answer:B [Frog]
Notes: Skin works as a respiratory organ in frog. The frog has three respiratory surfaces on its body which it uses to exchange gas with its surroundings: the skin, in the lungs and on the lining of the mouth.

Q 2.In Gymnosperms seeds are__________?
A. Always naked
B. Always covered
C. Naked in some and covered in others
D. Absent

Answer: Correct Answer:A [Always naked]
Notes: Gymnosperms are called so because they have naked ovules / seeds. In terms of plant evolution, they are first seed-bearing plants. They are inferior to Angiosperms because in Angiosperms, the ovules are covered.

Q 3.Which among the following plants is known as Indian ginseng?
A. Withania somnifera
B. Datura ceratocaula
C. Iberis amara
D. Capsella bursa pastoris

Answer: Correct Answer:A [Withania somnifera]
Notes: Withania somnifera or commonly called as Ashwagandha is known as Indian ginseng.

Q 4.As per the WHO definition, within how many days of the termination of pregnancy, the death of a woman is counted in the Maternal Mortality?
A. 36 Days
B. 42 Days
C. 56 Days
D. 60 Days

Answer: Correct Answer:B [42 Days]
Notes: As per the WHO definition, within 42 days of the termination of pregnancy, the death of a woman is counted in the Maternal Mortality, irrespective of the duration and site of the pregnancy.

Q 5.Which of the following fruits has its seed outside?
A. Mango
B. Banana
C. Strawberry
D. Orange

Answer: Correct Answer:C [Strawberry]
Notes: Strawberry is the fruit which has its seeds outside the body. The “seeds” on the outside of a strawberry are actually the plant’s ovaries and are called “achenes.” Each “seed” is technically a separate fruit that has a seed inside of it.

Q 6.HIV often changes its shape due to the presence of which of the following enzymes?
A. Reverse Transcriptase
B. Enterokinase
C. Nucleoditase
D. None of the above

Answer: Correct Answer:A [Reverse Transcriptase]
Notes: A reverse transcriptase is an enzyme used to generate complementary DNA from an RNA template, a process termed reverse transcription. The viral DNA is cut and paste into the host cell DNA. The host cell gets tricked into making lots of proteins for the virus.

Q 7.What is caused by the deficiency of Vitamin D?
A. Rickets
B. Night blindness
C. Pellagra
D. Scurvy

Answer: Correct Answer:A [Rickets]
Notes: Rickets is a skeletal disorder that’s caused by a lack of vitamin D, calcium, or phosphate. These nutrients are important for the development of strong, healthy bones. People with rickets may have weak and soft bones, stunted growth, and, in severe cases, skeletal deformities.

Q 8.Which of the following belongs to the Hypochondria?
A. Disease of eyes
B. Disease of sexual organs
C. Disease of low blood pressure
D. State of morbid anxiety about one’s own health, with complaint of imaginary disorders

Answer: Correct Answer:D [State of morbid anxiety about one’s own health, with complaint of imaginary disorders]
Notes: Hypochondria symptoms include a long-term and intense fear of having a serious condition and worry that minor symptoms indicate something serious. A person may frequently visit or switch doctors.

Q 9.Photosynthesis generally occurs in which portions of the plant?
A. Leaf and other chloroplast bearing parts
B. Steam and leaf
C. Roots and chloroplast bearing parts
D. Bark and leaf

Answer: Correct Answer:A [Leaf and other chloroplast bearing parts]
Notes: Photosynthesis can take place in leaves, stem or green part of plant which containing chlorophyll.

Q 10.The Six Kingdoms of Classification is also known as the latest classification system. By whom is it given?
A. C Woese
B. O Kandler
C. Mc Wheels.
D. Ernest Haeckel

Answer: Correct Answer:A [C Woese]
Notes: In biology, a scheme of classifying organisms into six kingdoms: Proposed by Carl Woese et al: Animalia, Plantae, Fungi, Protista, Archaea/Archaeabacteria, and Bacteria/Eubacteria.

Q 11.Who among the following was awarded the Nobel Prize in Medicine in 1926 for his contribution to cancer research?
A. Christiaan Eijkman
B. Johannes Fibiger
C. Julius Wagner-Jauregg
D. Charles-Jules-Henri Nicolle

Answer: Correct Answer:B [Johannes Fibiger]
Notes: Johannes Fibiger was awarded the Nobel Prize in Medicine in 1926 for his contribution to cancer research.

Q 12.On which of the following criteria is the five-state system done?
A. Structure of the nucleus
B. Structure of cell wall
C. Asexual Reproduction
D. Mode of Nutrition

Answer: Correct Answer:D [Mode of Nutrition]
Notes: The main criteria of the five kingdom classification were cell structure, body organisation, mode of nutrition and reproduction, and phylogenetic relationships.

Q 13.Which of the following cell organelles contain RNA?
A. Plastids
B. Mitochondria
C. Ribosomes
D. Lysosomes

Answer: Correct Answer:C [Ribosomes]
Notes: Ribosomes are small organelles that contain RNA and specific proteins within the cytoplasm.

Q 14.How many of the following blood cells are there in the human body?
A. 25 trillion
B. 15 trillion
C. 35 trillion
D. 55 trillion

Answer: Correct Answer:A [25 trillion]
Notes: Adult humans have an average of about 25 trillion RBCs in their bodies. Women usually have fewer RBCs than men

Q 15.When is reverse transcriptase a useful enzyme?
A. an RNA virus converts its RNA to DNA
B. there are no host cells present
C. nutrients are scarce
D. spikes are forming in the new virus

Answer: Correct Answer:A [an RNA virus converts its RNA to DNA]
Notes: Reverse transcriptase is a useful enzyme to have when an RNA virus converts its RNA to DNA. Reverse transcriptase converts RNA sequences into cDNA sequences that are capable of being inserted into different regions of the genome.

Q 16.What are the inclusion bodies of the measles virus?
A. intracytoplasmic
B. intranuclear
C. both (a) and (b)
D. none of these

Answer: Correct Answer:C [both (a) and (b)]
Notes: The inclusion bodies of the measles virus are intracytoplasmic and intranuclear.

Q 17.Which of the following is not an example of bryophytes?
A. Marchantia
B. Funaria
C. Sphagnum
D. Selaginella

Answer: Correct Answer:D [Selaginella]
Notes: Selaginella is not an example of bryophytes. Selaginella, Equisetum, Pteris, etc.are examples of Pteridophyta.

Q 18.What is involved in the release of pollen grains?
A. Pectin and cellulose
B. Lignocellulose
C. Pollenkit
D. Sporopollenin

Answer: Correct Answer:D [Sporopollenin]
Notes: Sporopollenin is the most chemically inert organic polymer. It is a major component of the tough outer (outer) walls of plant spores and pollen grains.

Q 19.What are the characteristics of Pteridophyta?
A. They are cryptogams, seedless and vascular
B. The plant body has true roots, stem and leaves
C. Spores develop in sporangia
D. All of the above

Answer: Correct Answer:D [All of the above]
Notes: Pteridophytes are considered the first plants to develop on land, they are cryptogams, seedless and vascular, the plant body has true roots, stems and leaves, spores develop into sporangia, sporangia in clusters on the sporophyll sex organs are multicellular.

Q 20.Where is the phloem located?
A. outer side of the vascular bundle.
B. centre of the vascular bundle
C. marginal regions of leaves and stems
D. None of these

Answer: Correct Answer:A [outer side of the vascular bundle.]
Notes: The xylem is located towards the adaxial surface of the leaf, whereas the phloem is located towards the axial surface of the leaf.

Q 21.The increase in shoot and root length is called which of the following?
A. Primary growth
B. Secondary growth
C. Little growth
D. None of these

Answer: Correct Answer:A [Primary growth]
Notes: The increase in the length of shoot and root is called primary growth. This shoot is the result of cell division in the apical meristem.

Q 22.Which of the following is not a characteristic of non-chordates?
A. cylindrical, triploblastic, coelomate, or pseudocoelomate animals
B. Modes of reproduction involve sexual and asexual
C. body includes a closed circulatory system
D. Respiration takes place through gills, trachea or body surface

Answer: Correct Answer:C [body includes a closed circulatory system]
Notes: Chordates body includes a closed circulatory system. Whereas non-chordates are cylindrical, triploblastic, coelomate, or pseudocoelomate animals, modes of reproduction involve sexual and asexual and respiration takes place through gills, trachea, or body surface.

Q 23.Which of the following are the simplest phyla?
A. Cnidaria
B. Ctenophora
C. Porifera
D. None of these

Answer: Correct Answer:C [Porifera]
Notes: Porifera are the simplest phyla. These are commonly called sponges. They are mostly marine and asymmetrical.

Q 24.Schistosoma and Fasciola are examples of which Phylum?
A. Ctenophora
B. Porifera
C. Aschelminthes
D. Platyhelminthes

Answer: Correct Answer:D [Platyhelminthes]
Notes: Schistosoma and Fasciola are examples of Platyhelminthes. Schistosoma causes Schistosomiasis which spreads through contaminated water and Fasciola causes fascioliasis in animals in which the liver of the animal enlarges and the bile ducts are blocked.

Q 25.Which of the following is the study of Molluscan Shell?
A. Conchology
B. Malacology
C. Entomology
D. Mastology

Answer: Correct Answer:A [Conchology]
Notes: Conchology is the study of mollusk shells. Conchology is one aspect of malacology, the study of molluscs.

Q 26.Flying dragon belongs to which of the following group?
A. Gecko
B. Iguanas
C. Chameleon
D. Tautra

Answer: Correct Answer:B [Iguanas]
Notes: Flying dragon belongs to Iguanas. Flying dragon is a genus of agamid lizards that are also known as Draco. They are arboreal insectivores.

Q 27.Into how many groups are Aves classified?
A. Two
B. Three
C. Four
D. Five

Answer: Correct Answer:A [Two]
Notes: The class Aves is divided into two groups – Archaeornithes and Neornithes

Q 28.Aerobic bones are found in which of the following?
A. Domestic lizard
B. Tadpole of frog
C. Flying lizard
D. Pigeon

Answer: Correct Answer:D [Pigeon]
Notes: Aerobic bones are found in Pigeon. Columbidae is a bird family of pigeons. It is the only family in the order Columbiformes. These are thick-bodied birds with short necks and short slender bills, with fleshy grains in some species.

Q 29.Which of the following cells is involved in humoral immunity?
A. T-cells
B. B-cells
C. Mast cells
D. Both T and B cells

Answer: Correct Answer:B [B-cells]
Notes: B cells are a type of lymphocyte responsible for the humoral immune component of the adaptive immune system.

Q 30.Which hormone regulates adrenocorticotropin release in the pituitary gland?
A. Thyrotropin releasing hormone
B. Corticotropin releasing hormone
C. Gonadotropin releasing hormone
D. Thyroid-stimulating hormone

Answer: Correct Answer:B [Corticotropin releasing hormone]
Notes: The corticotropin-releasing hormone regulates adrenocorticotropin release in the pituitary gland.

Q 31.Which of the following species of Plasmodium don’t cause Malaria?
A. Plasmodium piper
B. Plasmodium vivax
C. Plasmodium falciparum
D. Plasmodium malaria

Answer: Correct Answer:A [Plasmodium piper]
Notes: Plasmodium vivax, falciparum, and malariae species of Plasmodium cause Malaria. Whereas Plasmodium piper species of Plasmodium don’t cause Malaria.

Q 32.Who among the following invented Bt cotton?
A. Ernst Berliner
B. James Black
C. Erwin Chargaff
D. Rachel Carson

Answer: Correct Answer:A [Ernst Berliner]
Notes: Ernst Berliner invented Bt cotton. Genetically modified by the insertion of one or more genes from a common soil bacterium, Bacillus thuringiensis, known as Bt cotton.

Q 33.The number of chambers in a human heart is____:
A. Two
B. Three
C. Four
D. Five

Answer: Correct Answer:C [Four]
Notes: The human heart has four chambers, two superior atria and two inferior ventricles. The atria are the receiving chambers and the ventricles are the discharging chambers. The pathway of blood through the human heart consists of a pulmonary circuit and a systemic circuit.

Q 34.Solitary cymose inflorescence is observed in ____:
A. Rose
B. Tuberose
C. Chinarose
D. Gardenia

Answer: Correct Answer:D [Gardenia]
Notes: Solitary cymose inflorescence refers to a determinate inflorescence composed of a single flower. Examples include poppy, gardenia (ornamental plant), tulip, etc. Flowers are said to be solitary when the plant bears only one, or when single flowers appear on the ends of lateral branches that are remote from one another.

Q 35.Which of the following processes are associated with plants during dark period?
A. Respiration and transpiration
B. Transpiration and conduction
C. Photosynthesis and respiration
D. Conduction and respiration

Answer: Correct Answer:D [Conduction and respiration]
Notes: Conduction is the process by which vital nutrients are transported to the different parts of a plant. This process is independent of the light factor. Respiration process in plants is the intake of carbon-dioxide and exhales oxygen during the day as the plants gets energy through the photosynthesis process in which the carbon-dioxide is converted into sugars using the sun light energy, as this process uses carbon-dioxide and water, the resulting gas oxygen is given out as a waste product. During the night, as the photosynthesis process does not take place it exhales the carbon-dioxide itself.

Q 36.pH of the human blood is ____:
A. Slightly Acidic
B. Highly Acidic
C. Slightly Basic
D. Highly Basic

Answer: Correct Answer:C [Slightly Basic]
Notes: Acidity and alkalinity are expressed on the pH scale, which ranges from 0 (strongly acidic) to 14 (strongly basic or alkaline). A pH of 7.0, in the middle of this scale, is neutral. Blood is normally slightly basic, with a normal pH range of 7.35 to 7.45.

Q 37.Which type of pathogen causes the water-borne disease Ascariasis?
A. Viral
B. Protozoan
C. Parasitic
D. Bacterial

Answer: Correct Answer:C [Parasitic]
Notes: Ascariasis is a disease caused by the parasitic roundworm Ascaris lumbricoides. Infection occurs by eating food or drink contaminated with Ascaris eggs from feces. Ascariasis is most common in places without modern sanitation.

Q 38.Which part becomes modified as the tusk of elephant?
A. Premolar
B. Second incisor
C. Molar
D. Canine

Answer: Correct Answer:B [Second incisor]
Notes: Tusks are elongated, continuously growing front teeth (incisors) usually but not always in pairs, that protrude well beyond the mouth of certain mammal species. They are most commonly canines, as with warthogs, pig, and walruses but in the case of elephants, elongated incisors. In most tusked species both the males and the females have tusks although the males’ are larger.

Q 39.Turmeric is a modified ____:
A. Stem
B. Root
C. Leaves
D. Fruit

Answer: Correct Answer:A [Stem]
Notes: Turmeric, (Curcuma longa) is a perennial herbaceous plant of the ginger family (Zingiberaceae) that is tuberous rhizomeor underground stem. The turmeric plant is identifiable by both its characteristic tuberous root and the leaves that extend upward from erect, thick stems arising from the root. Turmeric root is actually a fleshy oblong tuber that is tapered at each end.

Q 40.Which of the following is not unicellular?
A. Euglena
B. Amoeba
C. Paramecium
D. Hydra

Answer: Correct Answer:D [Hydra]
Notes: Unicellular organism is an organism which only has one cell while a multicellular organism is an organism that made up of more than one cell. Organisms such as amoeba, plasmodium, paramecium are unicellular organisms. Hydra (animal) and spirogyra (plant) are examples of multicellular organism.

Q 41.Epidermal cells of which part of plant often secrete a waxy water resistant layer on their outer surface?
A. Aerial parts only
B. Roots only
C. Both aerial parts and roots
D. Neither aerial parts nor roots

Answer: Correct Answer:A [Aerial parts only]
Notes: The major role of epidermis is to protect all the parts of the plant. Epidermal cells on the aerial parts of the plant often secrete a waxy, water-resistant layer on their outer surface. This aids in protection against loss of water, mechanical injury and invasion by parasitic fungi.

Q 42.Animals with Chitinous exoskeleton are ____:
A. Sea-Urchin
B. Insects
C. Sponges
D. Snails

Answer: Correct Answer:B [Insects]
Notes: Chitin is the main component of the cell walls of fungi, the exoskeletons of arthropods such as crustaceans (e.g., crabs, lobsters and shrimps) and insects, the radulas of molluscs, and the beaks and internal shells of cephalopods, including squid and octopuses. Combined with calcium carbonate, as in the shells of Crustacean and molluscs, chitin produces a much stronger composite for protection.

Q 43.Which one of the following is known as the immovable property in the cell?
A. Nucleic acid
B. Fat
C. Protein
D. Carbohydrate

Answer: Correct Answer:A [Nucleic acid]
Notes: Nucleic acids are large biological molecules essential for all known forms of life. They include DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). They are merely transmitted from one generation to next.

Q 44.Which of the digestive organs contains acid?
A. Stomach
B. Colon
C. Small intestine
D. Appendix

Answer: Correct Answer:A [Stomach]
Notes: Gastric acid, gastric juice or stomach acid, is a digestive fluid, formed in the stomach. It is composed of hydrochloric acid (HCl), potassium chloride (KCl) and sodium chloride (NaCl). Gastric acid plays a key role in digestion of proteins, by activating digestive enzymes.

Q 45.Cinnamon is obtained from which part of the plant?
A. Bark
B. Stem
C. Fruits
D. Roots

Answer: Correct Answer:A [Bark]
Notes: Cinnamon is a spice obtained from the inner bark of several tree species from the genus Cinnamomum. Cinnamon is used mainly as an aromatic condiment and flavoring additive in a wide variety of cuisines. The aroma and flavor of cinnamon derive from its essential oil and principal component, cinnamaldehyde, as well as numerous other constituents, including eugenol.

Q 46.The virus of AIDS affects the growth of ____:
A. RBCs in blood
B. T cells in blood
C. Grey cells in brain
D. Haemoglobin

Answer: Correct Answer:B [T cells in blood]
Notes: Human immunodeficiency virus (HIV) attacks and kills crucial immune system cells, known as T-helper cells. A T cell, or T lymphocyte, is a type of lymphocyte (a subtype of white blood cell) that plays a central role in cell-mediated immunity. They are called T cells because they mature in the thymus from thymocytes.

Q 47.Cholesterol is absent in ___:
A. Groundnut oil
B. Butter oil
C. Butter milk
D. Ice Cream

Answer: Correct Answer:A [Groundnut oil]
Notes: 100g of peanut oil (groundnut oil) contains 17.7g of saturated fat, 48.3g of monounsaturated fat, 33.4g of polyunsaturated fat, and 0mg of cholesterol. It is fast replacing dairy products due to the absence of cholesterol.

Q 48.Which of the following hormones is known to be helpful in coping with stress?
A. Serotonin
B. Calcitonin
C. Melatonin
D. Testosterone

Answer: Correct Answer:A [Serotonin]
Notes: Serotonin is a chemical that relays information from one part of the brain to another and is known to play a key role in a number of functions ranging from sleep to social behaviour. Indian scientists have discovered that serotonin boosts energy production in brain cells and helps them survive under stress.

Q 49.Capra Hircus is the scientific name of ____:
A. Sheep
B. Cow
C. Horse
D. Goat

Answer: Correct Answer:D [Goat]
Notes: Capra Hircus is the scientific name of domestic goat or simply goat. It is a subspecies of C. aegagrus domesticated from the wild goat of southwest Asia and Eastern Europe. The goat is a member of the animal family Bovidae and is closely related to the sheep; both are placed in the goat-antelope subfamily Caprinae.

Q 50.Yellow spots on citrus leaves is due to the deficiency of _____:
A. Zinc
B. Iron
C. Boron
D. Magnesium

Answer: Correct Answer:D [Magnesium]
Notes: The deficiency of magnesium leads to yellowish green blotch near the base of the leaf between the midrib and the outer edge (chlorosis). The yellow area enlarges until the only green remaining is at the tip and base of the leaf as an inverted V-shaped area on the midrib.

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