All Free Biology MCQs with Answers

1051. Complex symptoms like severe pneumonia vascular tumor sudden weight loss swollen lymph nodes and immune deficiency are features of:

• A. Polio
• B. Hepatitis
• C. AIDS
• D. HIV

Explanation: AIDS is the advanced syndrome caused by HIV, involving severe immune deficiency and opportunistic problems such as pneumonia, lymph-node enlargement, weight loss, and certain tumours. HIV is the causative virus, not the name of the collection of clinical symptoms, so students often choose HIV by confusing cause with disease.

1052. Which of the following statement about AIDS is incorrect:

• A. is a host specific disease
• B. An infected mother cannot pass the virus to her baby.
• C. Results in enlargement of lymph nodes
• D. Can be prevented.

Explanation: An infected mother can transmit HIV to her baby during pregnancy, childbirth, or breastfeeding, so that statement is incorrect. AIDS is host-specific, may cause enlarged lymph nodes, and its transmission risk can be reduced or prevented through appropriate measures; students may select another option because prevention is not absolute without treatment and precautions.

1053. Which one of the following specially result in chronic liver disease leading to hepatic failure:

• A. HAV
• B. HBV
• C. HCV
• D. HEV

Explanation: HCV commonly persists after the initial infection and can cause chronic hepatitis, cirrhosis and hepatic failure. HAV and HEV usually cause acute disease, while HBV can also become chronic but is less specifically associated with the stated result in this question. Students may choose b because chronic HBV infection can also damage the liver.

1054. Operculum is present in_____________?

• A. bony fish
• B. sea fish
• C. cartilaginous fish
• D. none of these

Explanation: An operculum is a bony flap that covers and protects the gills of bony fish, helping direct water over the gill surfaces. Cartilaginous fish generally have separate exposed gill slits and lack a bony operculum, making them the likely alternative choice. “Sea fish” is too broad because both bony and cartilaginous fishes can live in the sea.

1055. Biological organization is_____________?

• A. simple
• B. advance
• C. complex
• D. highly complex

Explanation: Biological organization is described as highly complex because living systems are arranged in levels, from molecules and organelles through cells, tissues, organs, organ systems, organisms, and higher groups. “Complex” is less precise because the standard description emphasizes a very high degree of organized complexity. Students may choose “complex” because it sounds scientifically reasonable but omits the intended degree.

1056. True roots absent in_____________?

• A. ferns
• B. bryophytes
• C. gymnosperms
• D. angiosperms

Explanation: Bryophytes lack true roots, stems, and leaves and instead possess rhizoids that mainly anchor the plant. Ferns, gymnosperms, and angiosperms are vascular plants with true roots. Students may choose ferns because they are relatively simple plants, but ferns still have a proper vascular root system.

1057. Which is a parasitic plant?

• A. cuscuta
• B. rose
• C. ferns
• D. mosses

Explanation: Cuscuta, or dodder, is a parasitic plant that obtains water and nutrients from a host through specialized haustoria and has greatly reduced photosynthesis. Rose is an ordinary autotrophic plant, while ferns and mosses are also generally photosynthetic. Students may choose mosses because they lack vascular tissue, but lack of vascular tissue does not make a plant parasitic.

1058. Most cell membranes are composed principally of ?

• A. DNA ad protein
• B. Protein and Lipids
• C. Protein and Chitin
• D. Protein and RNA

Explanation: The basic structure of most cell membranes is a phospholipid bilayer with proteins embedded in or attached to it. DNA and protein or protein and RNA are associated mainly with genetic material and ribosomes, which makes option a a likely mistaken choice.

1059. A structure formed by groups of similar cells organized into loose sheets or bundles performing similar functions is called as:

• A. An organ
• B. An organism
• C. A Tissue
• D. A Cell

Explanation: A tissue is formed when similar cells are organized together to perform a common function, whether arranged in sheets or bundles. An organ contains several different tissues working together, so option a reflects confusing the smaller level of organization with the larger one.

1060. Which character differentiates living things from non-living organisms?

• A. They live in the same ecosystem.
• B. They are highly organized and complex made of one or more cells and contain genetic material
• C. They are acted upon by the same environment
• D. Both a and b

Explanation: Living organisms are cellular, highly organized, and contain genetic material that directs growth, maintenance, and reproduction. Students may choose both a and b because living and non-living things share an environment, but sharing an ecosystem does not distinguish life from non-life.