CBSE Class 7 Science Advanced Biology Basis of Classification MCQs Set 01

Answer: (b) Linnaeus

Explanation:
1. Taxonomy is the science of identifying, grouping and naming organisms.
2. Carolus Linnaeus gave the two-part naming system and laid the foundation of this science, so he is called its father.
3. Aristotle gave an early classification, Whittaker gave five kingdoms and Darwin is known for evolution. The answer is (b) Linnaeus.

Teacher's Note:
1. Link each scientist with one contribution: Linnaeus with naming, Whittaker with five kingdoms.
2. Do not confuse an early classifier (Aristotle) with the father of taxonomy.

Answer: (a) class

Explanation:
1. The hierarchy runs species, genus, family, order, class, phylum, kingdom.
2. Related families make an order, and related orders make a class.
3. A phylum is made of related classes and a kingdom of related phyla.

Teacher's Note:
1. Remember the seven levels in order from the bottom.
2. The level just above order is class.

Answer: (c) plantae

Explanation:
1. Autotrophs make their own food, and multicellular means the body has many cells.
2. Fungi and Animalia are heterotrophic, and Protista is unicellular.
3. Only kingdom Plantae has multicellular autotrophs.

Teacher's Note:
1. Use two clues together: body organization and nutrition.
2. Green plants are the standard example.

Answer: (a) fungi and animalia

Explanation:
1. Heterotrophs depend on others for food, and multicellular organisms have many cells.
2. Fungi (some are multicellular) and Animalia fit both clues.
3. Protista and Monera are unicellular, so options (b), (c) and (d) are wrong. The answer is fungi and animalia.

Teacher's Note:
1. Check each kingdom against both conditions.
2. Fungi can be unicellular or multicellular, but never autotrophic.

Answer: (d) parasites

Explanation:
1. An organism that lives on or in another living organism (the host) and takes food from it is a parasite.
2. Saprophytes feed on dead and decaying matter, and autotrophs make their own food.

Teacher's Note:
1. Parasite means taking food from a living host.
2. A saprophyte uses dead matter, not a living host.

Answer: (c) A-(iii), B-(iv), C-(i), D-(ii)

Explanation:
1. Linnaeus proposed the two-kingdom classification: A-(iii).
2. Whittaker proposed the five-kingdom classification: B-(iv).
3. Monera has unicellular prokaryotes (bacteria): C-(i).
4. Protista has unicellular eukaryotes: D-(ii).
5. The correct matching is option (c).

Teacher's Note:
1. Match the sure pairs first and eliminate the options.
2. Monera is prokaryotic; every other kingdom is eukaryotic.

Answer: (c) fungi

Explanation:
1. Yeast is single-celled and eukaryotic, but it cannot make its own food.
2. Organisms that are eukaryotic and heterotrophic and include yeast, mushroom and bread mould belong to kingdom Fungi.

Teacher's Note:
1. Yeast is a unicellular fungus, an exception students often miss.
2. Do not put every unicellular organism in Protista.

Answer: (c) Linnaeus classified animals into different groups according to their habitat.

Explanation:
1. Statements (a) and (b) are correct: DNA in the nucleus controls characters, and Monera are prokaryotes with no true nucleus.
2. Statement (d) is correct: Aristotle grouped plants as herbs, shrubs and trees by stem.
3. Grouping animals by habitat (air, water, land) was done by Aristotle, not Linnaeus, so statement (c) is wrong.

Teacher's Note:
1. In a 'wrong statement' question, test each option and pick the false one.
2. Aristotle used habitat for animals; Linnaeus used food and movement.

Answer: (a) genus

Explanation:
1. In the hierarchy, the level above species is genus.
2. Related genera make a family, related families an order and related orders a class.

Teacher's Note:
1. Species is the lowest level and genus comes next.
2. Lion and tiger are different species of the same genus.

Answer: (c) birds

Explanation:
1. Aves is the class of birds.
2. Reptiles belong to Reptilia, and fishes to Pisces.

Teacher's Note:
1. The class names Mammalia, Aves, Reptilia and Pisces are worth memorising.
2. Aves comes from the Latin word for birds.

Answer: (a) Both A and R are true, and R is the correct explanation of A.

Explanation:
1. Bacteria are prokaryotes, so the assertion is true.
2. Prokaryotes have no true nucleus; the genetic material lies in the nucleoid, so the reason is true.
3. Having no well-defined nucleus is exactly what makes an organism a prokaryote, so R explains A. The answer is (a).

Teacher's Note:
1. A prokaryote is defined by the absence of a true nucleus.
2. When the reason is the definition of the term in the assertion, it is the explanation.

Answer: (b) Both A and R are true, but R is not the correct explanation of A.

Explanation:
1. Protista contains unicellular eukaryotes such as Amoeba, so the assertion is true.
2. Protists may be autotrophic or heterotrophic, so the reason is true.
3. The nutrition mode is not why unicellular eukaryotes are placed in Protista (cell type and body organization are), so R does not explain A. The answer is (b).

Teacher's Note:
1. Both statements can be true without one explaining the other.
2. Ask whether R answers 'why' for A.