Biology Class 12 MCQs With Answers

Ans: c

Explanation: In the Monera group, maximum nutritional diversity is included. All modes of nutrition are possible, photoautotrophic, heterotrophic and chemoautotrophic are the three modes of nutrition. Fungi and Animalia include only heterotrophic types. Examples of heterotrophs are parasitic, saprophytic and symbiotic. The organisms Plantae contains most of all the autotrophic forms.

Ans: a

Explanation: all, eukaryotes have a nuclear membrane. Agaricus, Penicillium are eukaryotes. Volvox is an alga, alga also has their nuclear membrane. But Nostoc doesn’t fall under both categories. It’s neither a eukaryote nor an alga. It comes under cyanobacterium, i.e., It’s a prokaryote. Being a prokaryote it doesn’t have a nuclear cell in the membrane. So it is clear that nuclear membrane is absent in Nostoc.

Ans: c

Explanation: fungi store the oil and glycogen in them. Animal & fungus stores glycogen which is a kind of food. In animals and fungus kingdoms, the most common polysaccharide retention molecule is glycogen is made with several glucose units. As per the result of it, Glycogen can split into multiple glucose residues.

Ans: a

Explanation: paramecium is one of the protozoans. They are single-celled protozoans & the size of a paramecium is between 50 to 300um. Paramecium is primarily found in aquatic environments. They belong to the kingdom Protista. The protozoa ciliate are categorized as eukaryotes, they are from the Protista kingdom. Thus the correct option is A.

Ans: c

Explanation: an organelle, heterocyst that is found in nitrogen-fixation cells. It is a cyanobacterial cell which is undergone differentiation. There are some aerobic circumstances in which the heterocysts serve as the nitrogen-fixation sites. In the 4 above-given options fragmentation, fruit storage, symbiotic relation, and nitrogen- fixation the correct option is Nitrogen-fixation.

Explanation: In five kingdoms there are so many organisms that belong to different groups. Chlorella and Chlamydomonas belong to the kingdom Protista. Previously they were classified as Algae. All the unicellular organisms belonging to the kingdom Protista chlorella and Chlamydomonas are unicellular organisms. The prokaryotes belong to the Monera kingdom.

Ans: b

Explanation: Biological techniques that classify & divide the organisms into groups based on similar characteristics. The cladistics technique is used to establish a direct lineage to share the ancestry common. It is also used to develop the exact creature of the organism. After categorizing the organisms into different groups we must know how closely the species were connected.

Ans: a

Explanation: Taxonomy is just like the science of classifying organisms into different groups. It is a way to categorize the organism and to make a difference among all of them. The main purpose of the taxonomy is to identify unknown species based on their characteristics. As per their characteristics, different names are given to them.

Ans: a

Explanation: Botanical garden is the study and conservation of plants, they devote all their resources towards the study and conservation of the plants. They help in making the plant species diverse in the world for the public. A botanical garden plays a prominent role in observing the needs of humans and providing well-being to them.

Ans: d

Explanation: Archaebacteria is an ancient bacteria group that is living in extreme environments. They are primitive single called microorganisms. They have no nucleus. The main characteristics of Archaebacteria are that they had a fatty acid synthetase in them. It is the main characteristic of Archaebacteria among all of the given options.

Ans: d

Explanation: all the cells communicate through signals. These signals are chemical signals. In multicellular organisms, cell to cell communication occurs. All the Categories of chemical signaling that are found in multicellular organisms are autocrine signaling, endocrine signaling, paracrine signaling, and signaling by direct contact. Here in the options three of them are given so the correct option is (d) all of the above.

Ans: c

Explanation: paracrine signaling is a type of cell signaling. In cells, signaling communication is done through chemical signaling. In paracrine signaling, one cell communicates with the other one but they communicate over moderately short distances. This signaling is called paracrine signaling. The correct option is C because paracrine signaling is part of chemical signaling.

Ans: c

Explanation: Cell signaling is a process by which some specific information is transferred from the surface of the cell to the cytosol & the nucleus. Cell signaling can be intercellular or can also be intracellular. When the communication is done within a cell then it is called intracellular signaling & when the communication is done between cells then it is called intercellular cell signaling. So the correct option is C.

Ans: d

Explanation: Cell signaling is used to study the signaling process of an organism, the signaling is done between the cells. Cell signaling helps study the context of human diseases. Cell signaling is a process of signaling between the cells. Cell signaling occurs through phytohormones in plants. It is an important process & tells signaling is done through chemical signals. In the above-given options, all of the three are correct so t correct option is D.

Ans: c

Explanation: all the cells receive signals in chemical form through various signaling molecules. These signal molecules are called ligands. These ligands carry a message that is often relayed through a chemical messenger chain within the cell. The signal molecules are ligands that bind to the receptors of the cell surface & expressed by their target cells. Gastrin, glucagon & insulin interact with the cell surface receptors. Testosterone does not interact with the cell surface receptors. So the correct option is C.