All Free Biology MCQs with Answers

• A. Ronald
• B. AFA king
• C. Laveran
• D. Aristotle

Explanation: Charles Louis Alphonse Laveran, a French physician, was the one who stated the hypothesis that mosquitoes are involved in the spread of…

• A. Euglenophyta
• B. Pyrrophyta
• C. Chrysophyta
• D. Both A and B

Explanation: Euglenophyta, commonly known as euglenoids, are a group of unicellular organisms that possess chloroplasts and are capable of…

• A. merozoites increase their population in RBC and burst open the RBC
• B. sporozoites enter the bloodstream
• C. sporozoites enter the liver cells.
• D. merozoites come out of the liver cells.

Explanation: During the erythrocytic stage of the plasmodium life cycle, merozoites invade red blood cells and reproduce inside them.

• A. Plasmodia are the cause of malaria.
• B. Bad air is involved in the spread of malaria.
• C. Mosquitoes are possible carriers of Plasmodium.
• D. Malaria is caused by bad air coming from marshy places.

Explanation: Ronald Ross's hypothesis and subsequent research demonstrated that mosquitoes, particularly the Anopheles species, are vectors for the…

• A. sporozoa
• B. sarcodina
• C. mastigophora
• D. microspora

Explanation: Entamoeba belongs to the subphylum Sarcodina, which includes protozoans that move and feed using temporary projections of their cell…

• A. Cholera, typhoid, and tetanus are well-known diseases caused by viruses.
• B. Dinoflagellates, euglenoids and slime moulds are placed under kingdom Monera
• C. Members of kingdom Protista are primarily aquatic
• D. Dinoflagellates are the chief 'producers' in the oceans

Explanation: The kingdom Protista consists of a diverse group of eukaryotic microorganisms, many of which are found in aquatic environments.

• A. Chitin
• B. Cellulose
• C. Murein
• D. Lignin

Explanation: The cell wall of fungus like protista is composed of chitin.

• A. Protomycota
• B. Gymnomycota
• C. Oomycota
• D. Deuteromycota

Explanation: Phylum Deuteromycota is a polyphyletic group of asexually-reproducing fungi that do not display a sexual phase; they are known as imperfect.

• A. Pigs and rats
• B. Pigs and monkeys
• C. Rats and dogs
• D. Cats and sheep

Explanation: Swine are the primary reservoir hosts of Balantidium coli. Humans can also be reservoirs, and other potential animal hosts include…

• A. Trichonella
• B. Tripanosoma
• C. Trichonympha
• D. Trichina

Explanation: Although termites are insects that eat wood, they are not capable of digesting wood on their own.

• A. Red algae
• B. Brown algae
• C. Green algae
• D. Diatoms

Explanation: The brown algae comprise the class Phaeophyceae, golden-brown algae that range from small filamentous forms to large, complex seaweeds.

• A. Obligate parasites
• B. Facultative parasite
• C. Malarial parasites
• D. Pathogenic parasites

Explanation: Apicomplexan, also called sporozoan, are protozoan of the (typically) spore-producing phylum Apicomplexa.

• A. Diatoms
• B. Red-algae
• C. Green-algae
• D. Brown-algae

Explanation: Kelps are brown algae, known for their large size and complex structure, often forming dense underwater forests in cold oceanic regions.

• A. A flagellum
• B. A cillium
• C. An extended pseudopod
• D. A pellicle

Explanation: Pellicle is a thick cuticle and it is not a locomotor organ so option D is incorrect. Whereas pseudopods are cytoplasmic extensions.

• A. Euglenoids
• B. Rhodophyta
• C. Diatoms
• D. Dinoflagellates

Explanation: Poisonous red tides are caused by algae so the correct option is D i.e Dinoflagellates

• A. A fungus
• B. An algae
• C. A protozoan
• D. A prokaryote

Explanation: Students should learn that Acetabularia Mediterranea is a green algae

• A. Red-algae
• B. Blue-algae
• C. Green-algae
• D. Brown-algae

Explanation: Students should learn that most conspicuous sea-weeds are brown algae

• A. Pelicle
• B. Cell wall
• C. Sheath
• D. Cuticle

Explanation: The pellicle is the outer flexible covering found in ciliates, which are a type of microorganism.

• A. Plants
• B. Bacteria
• C. Animal
• D. Viruses

Explanation: Protozoa actually have characteristics that are more closely similar to animals rather than plants.

• A. Liver
• B. Skin
• C. Brain
• D. Lungs

Explanation: The largest organ in the human body is the skin. It covers and protects our entire body, acting as a barrier against external elements.