A Level Biology (A2) chapter 7: Classification, biodiversity and conservation MCQs with answers
By Team Megalecture · Updated 4 Nov 2026
58 exam-style questions on Classification, biodiversity and conservation, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.
Ten Classification, biodiversity and conservation questions with answers
Try each one, then open the answer. These ten stay the same; the test draws new ones every time.
1. A population of an endangered frog lives in a single protected pond and has declined to 40 individuals. Why is it still at high risk of extinction even though its habitat is now protected?
A
small populations always have higher mutation rates, producing harmful alleles
B
inbreeding in a small population increases the proportion of heterozygotes
C
low genetic diversity may leave it unable to adapt to disease or climate change
D
a small population cannot be affected by competition from other species
Show answer
Answer: C. A small population has lost much of its genetic variation, so it is less likely to include individuals with alleles that allow survival when conditions change, such as a new disease or a warmer climate. Inbreeding increases homozygosity, and chance events can also wipe out a small population.
2. Which method is most suitable for estimating the size of the population of a species of ground beetle in a woodland?
A
a line transect
B
percentage cover in frame quadrats
C
Simpson's index of diversity
D
mark-release-recapture
Show answer
Answer: D. Ground beetles move about, so they cannot be counted reliably in fixed quadrats. Marking a sample, releasing it and recapturing a second sample gives an estimate of population size using the Lincoln index.
3. A scientist measured light intensity and the height of 15 plants of one species. Both sets of data are continuous and normally distributed, and a scatter graph suggests a linear relationship. Which statistical test is most suitable?
A
the chi-squared test
B
the t-test
C
Pearson's linear correlation
D
Simpson's index of diversity
Show answer
Answer: C. Pearson's test measures linear correlation between two sets of continuous, normally distributed data. Chi-squared compares observed and expected frequencies, and the t-test compares two means.
4. Why does hunting by humans often reduce populations of large mammals, such as rhinoceroses, faster than they can recover?
A
they have few young and breed slowly, so losses are replaced slowly
B
they have no natural predators, so hunting is the only control on their numbers
C
they produce many young, but hunters kill most of them before they can breed
D
their food plants run out quickly
Show answer
Answer: A. Large mammals typically have long gestation, small numbers of young and long generation times. When adults are killed faster than they are replaced, the population falls, and small populations also lose genetic diversity.
5. Two animals belong to the same order but to different families. Which statement about them must be true?
A
they are in the same genus but in different species
B
they are in different classes but in the same phylum
C
they are in the same class and in the same genus
D
they are in the same class but in different genera
Show answer
Answer: D. Belonging to one order means they share every higher rank (class, phylum, kingdom). A genus sits inside one family, so animals in different families must be in different genera.
6. Which feature is found in organisms of the domain Bacteria but not in the domain Archaea?
A
peptidoglycan in the cell wall
B
70S ribosomes in the cytoplasm
C
a circular DNA molecule
D
a cell surface membrane
Show answer
Answer: A. Bacterial cell walls contain peptidoglycan (murein), which Archaea lack. Both kinds of prokaryote have 70S ribosomes, circular DNA and a cell surface membrane.
7. An embryo of an endangered species of antelope is produced by IVF. It is then placed in the uterus of a female of a closely related, more common species, which gives birth to the young. What is this female called?
A
a surrogate mother
B
an egg donor
C
a founder female
D
a hybrid mother
Show answer
Answer: A. Embryo transfer puts the embryo into a surrogate mother, who carries it to birth although the offspring is not genetically hers. The endangered female provided the egg.
8. Which statement describes the morphological species concept?
A
organisms of one species can produce fertile offspring together
B
organisms of one species share the same structural features
C
organisms of one species have the same role in an ecosystem
D
organisms of one species are all found in one geographical area
Show answer
Answer: B. The morphological species concept groups organisms by their observable structure (morphology). The biological concept uses interbreeding and the ecological concept uses the niche.
9. Why can an invasive alien species often increase in number rapidly after it is introduced to a new area?
A
it has a higher mutation rate
B
it is protected from competition with native species in the new area
C
it often has no natural predators or diseases there
D
it can feed only on species that are already very common in the area
Show answer
Answer: C. In its native range, predators, parasites and pathogens limit its numbers. These are usually absent in the new area, so its population can grow rapidly and take over resources from native species.
10. Which row correctly compares the membrane lipids of Archaea and Bacteria?
A
Archaea: ester bonds and unbranched chains; Bacteria: ether bonds and branched chains
B
Archaea: ester bonds and branched chains; Bacteria: ether bonds and unbranched chains
C
Archaea: ether bonds and unbranched chains; Bacteria: ester bonds and branched chains
D
Archaea: ether bonds and branched chains; Bacteria: ester bonds and unbranched chains
Show answer
Answer: D. Archaeal membrane lipids have branched hydrocarbon chains joined to glycerol by ether bonds. Bacteria, like eukaryotes, have unbranched fatty acid chains joined to glycerol by ester bonds.
Classification, biodiversity and conservation: questions students ask
How many Classification, biodiversity and conservation MCQs are there?
58, each with the answer and a short explanation, across 3 topics: Classification, Biodiversity, Conservation. Every chapter test draws ten of them, so you can take it many times.
Is the A Level Biology (A2) chapter 7 test free?
Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.
How is the chapter test marked?
The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.
