Sample 1Easy
The number of species that are known and described on Earth ranges between
- A
0.17 and 0.18 million
- B
1.7 and 1.8 million
- C
17 and 18 million
- D
170 and 180 million
Show the answer
The answer is B.The number of species known and described ranges between 1.7 and 1.8 million. This number and variety of organisms is what we call biodiversity.
- A.
Ten times too small.
- C.
Ten times too large; this is not the described count.
- D.
A hundred times too large.
NCERT: Class 11 Biology, Chapter 1 (The Living World), Diversity in the Living World
Sample 2Medium
Consider the following statements about growth as a characteristic of living organisms:
I. Increase in mass and increase in number of individuals are twin characteristics of growth.
II. In plants, growth by cell division occurs continuously throughout their life span.
III. Non-living objects such as mountains, boulders and sand mounds also grow, by accumulation of material on the surface.
IV. Growth is therefore a defining property of living organisms.
Which of the above are correct?
- A
I and II only
- B
I, II and III only
- C
II, III and IV only
- D
I, II, III and IV
Show the answer
The answer is B.Statements I, II and III are what NCERT states about growth. Because non-living things also grow (by accumulation on the surface, whereas living organisms grow from inside), NCERT concludes that growth cannot be taken as a defining property of living organisms, so IV is wrong.
- A.
Leaves out III: NCERT does say mountains, boulders and sand mounds grow.
- C.
Includes IV, which NCERT rejects because non-living things also grow.
- D.
Includes IV, which NCERT rejects because non-living things also grow.
NCERT: Class 11 Biology, Chapter 1 (The Living World), 1.1 What is 'Living'? (2022 edition)
Sample 3NEET level
The housefly belongs to the genus Musca and the phylum Arthropoda. How many taxonomic categories lie between its genus and its phylum, excluding both?
- A
1
- B
2
- C
3
- D
4
Show the answer
The answer is C.Musca (genus) → Muscidae (family) → Diptera (order) → Insecta (class) → Arthropoda (phylum). Family, order and class lie between, so the answer is 3.
- A.
Counts only the family.
- B.
Misses one of family, order or class.
- D.
Counts the genus or the phylum as well.
NCERT: Class 11 Biology, Chapter 1 (The Living World), Taxonomic Categories (organisms with their taxonomic categories)