Biology Comprehensive Practice Test 1

Questions

100

Marks

Sections

100%

Auto-Graded

Section	Questions	Marks each	Total marks
A — Multiple Choice	15	2	30
B — True / False	10	2	20
C — Fill in the Blank	10	2	20
D — Column Matching	5 pairs	2	10
E — Short Answer	5	4	20
Total	45	—	100

Fill-in-the-blank answers are checked against accepted spellings of the key term. Short answers are marked against a marking guide: write a full answer (at least 8 words) and you earn marks for each key idea you include. After you submit, every question shows the correct answer with a short explanation.

Section A — Multiple Choice

30 marks

15 questions · 2 marks each. Choose the best answer.

1.Which statement best explains why biology is considered an integrative science?Basic2 pts

A. It studies only the structure and anatomy of the human body

B. It focuses mainly on naming and classifying organisms into groups

C. It connects processes across molecular, cellular, organismal and ecological levels

D. It avoids using any ideas from chemistry, physics or mathematics

Why: The correct answer is C. Biology links many levels of life, from molecules to ecosystems, and uses ideas from chemistry and physics. That is why it is called integrative.

2.Which structure is the basic unit of life?Basic2 pts

A. Cell

B. Tissue

C. Organ

D. Ecosystem

Why: The correct answer is A. The cell is the smallest unit that shows all the features of life. Tissues, organs and ecosystems are larger levels built from cells.

3.A cell membrane is especially important because it:Basic2 pts

A. Stores all of the cell's hereditary information in its own DNA

B. Builds every protein that the cell needs by itself

C. Completely blocks all substances from entering or leaving the cell

D. Controls the movement of substances between the cell and its surroundings

Why: The correct answer is D. The membrane is selectively permeable: it lets some substances cross and keeps others out. Hereditary information is stored in DNA, not in the membrane.

4.Which sequence moves from smaller to larger levels of biological organisation?Basic2 pts

A. Organ → tissue → cell → organism

B. Cell → tissue → organ → organism

C. Organism → organ → tissue → cell

D. Ecosystem → organism → organ → cell

Why: The correct answer is B. Cells form tissues, tissues form organs, and organs work together in an organism. The other sequences run in the wrong order.

5.An ecosystem includes:Basic2 pts

A. Only the animals and birds that live together in a habitat

B. Only the plants, fungi and microorganisms found in a habitat

C. A single population made up of one species only

D. Living organisms together with their physical environment and their interactions

Why: The correct answer is D. An ecosystem is both the living part (biotic) and the non-living part (abiotic: water, soil, light, temperature), plus the interactions between them.

6.Which example is a population?Intermediate2 pts

A. All the frogs of one species living in a pond

B. All the organisms living in a pond

C. A frog and the water around it

D. All the ecosystems on Earth

Why: The correct answer is A. A population is one species in one area. All organisms in a pond make a community; a frog with its water is part of an ecosystem.

7.Biodiversity can include variation:Intermediate2 pts

A. Only between different ecosystems

B. Within genes, among species and among ecosystems

C. Only among individual humans

D. Only in body size

Why: The correct answer is B. Biodiversity is measured at three levels: genetic diversity, species diversity and ecosystem diversity.

8.A hypothesis is strongest scientifically when it:Intermediate2 pts

A. Cannot be tested by any experiment

B. Is based only on personal opinion

C. Produces predictions that can be tested

D. Is accepted by everyone without evidence

Why: The correct answer is C. A good hypothesis makes predictions that observations or experiments could support or contradict. Agreement or opinion alone does not make it scientific.

9.Homeostasis refers to:Intermediate2 pts

A. Permanent and unlimited growth of an entire organism

B. Regular movement of organisms between different ecosystems

C. Evolution of a species over time

D. Regulation of internal conditions within suitable ranges

Why: The correct answer is D. Homeostasis keeps conditions such as temperature and water balance within a range that cells can tolerate.

10.Natural selection can change a population when:Intermediate2 pts

A. Individuals consciously choose which useful mutations to develop

B. Heritable variation affects survival and reproductive success in a particular environment

C. All individuals in the population are genetically identical

D. Traits are never passed on from parents to their offspring

Why: The correct answer is B. Selection needs variation that is inherited and that affects survival or reproduction. Individuals do not choose their mutations.

11.Which observation is quantitative?Advanced2 pts

A. The leaf looks darker

B. The fish behaved unusually

C. The plant grew 4.2 cm in seven days

D. The solution became cloudy

Why: The correct answer is C. A quantitative observation is a measurement with a number and a unit. The others describe qualities without measuring them.

12.A food web is more informative than a simple food chain because it:Advanced2 pts

A. Shows interconnected feeding relationships among organisms

B. Shows only a single feeding relationship in a habitat

C. Leaves out the decomposers and the producers

D. Measures exact population sizes

Why: The correct answer is A. A food chain follows one path of energy. A food web joins many chains and shows that most organisms feed on, and are eaten by, several others.

13.If a habitat loses a major producer, the first major ecological effect is likely to involve:Advanced2 pts

A. Immediate creation of a new species

B. No change, because consumers make their own food

C. An increase in the numbers of every population

D. Reduced energy entering the food web

Why: The correct answer is D. Producers bring energy into the food web. Consumers cannot make their own food, so less producer energy means less for every level above.

14.Which statement best connects evolution and biodiversity?Advanced2 pts

A. Evolution removes all variation among living organisms over time

B. Evolution contributes to diversification and differences among lineages

C. Biodiversity prevents evolution from ever occurring in a habitat

D. They are unrelated processes

Why: The correct answer is B. Over long periods, evolution produces new species and differences between groups. This is one major source of biodiversity.

15.A strong biological explanation of a declining frog population should first:Advanced2 pts

A. Gather evidence and consider interacting factors such as habitat, disease, predation and climate

B. Assume a single cause and look only for evidence that supports that idea

C. Ignore environmental conditions and focus on the animals alone

D. Use a single population size without any time frame or comparison

Why: The correct answer is A. Population declines usually have several interacting causes, so a good explanation starts from evidence over time and considers more than one factor.

Section B — True / False

20 marks

10 questions · 2 marks each.

16.All living organisms are multicellular.Basic2 pts

True

False

Why: The answer is False. Many organisms, such as bacteria and amoeba, are made of a single cell.

17.Cells maintain organised internal processes using energy and information.Basic2 pts

True

False

Why: The answer is True. Cells use energy (for example from food) and genetic information (DNA) to keep their processes organised.

18.A community includes organisms of different species living and interacting in an area.Basic2 pts

True

False

Why: The answer is True. A community is all the populations of different species living together in one area.

19.An ecosystem contains only living components.Basic2 pts

True

False

Why: The answer is False. An ecosystem also includes non-living parts such as water, soil, light and temperature.

20.Homeostasis means that every internal condition remains perfectly constant.Basic2 pts

True

False

Why: The answer is False. Conditions vary a little; homeostasis keeps them within a suitable range, not perfectly fixed.

21.A scientific conclusion can be revised when strong new evidence appears.Intermediate2 pts

True

False

Why: The answer is True. Science is self-correcting: conclusions change when better evidence is found.

22.Natural selection acts on populations across generations, not because individuals deliberately choose to evolve.Intermediate2 pts

True

False

Why: The answer is True. Selection is a process in populations over generations. Individuals do not choose it.

23.Biodiversity refers only to the number of species in a habitat.Advanced2 pts

True

False

Why: The answer is False. Biodiversity also includes genetic variation within species and variety of ecosystems.

24.Energy generally enters many ecosystems through producers and is transferred through feeding relationships.Advanced2 pts

True

False

Why: The answer is True. Producers capture energy (usually sunlight) and pass it on when consumers eat them.

25.A correlation by itself always proves that one biological variable causes another.Advanced2 pts

True

False

Why: The answer is False. Two variables can change together without one causing the other. Cause needs controlled evidence.

Section C — Fill in the Blank

20 marks

10 questions · 2 marks each. Type the missing word or term.

26.The basic structural and functional unit of life is the ______.Intermediate2 pts

Why: The cell is the basic unit of life.

27.The maintenance of relatively stable internal conditions is called ______.Intermediate2 pts

Why: Homeostasis keeps internal conditions within a suitable range.

28.A group of organisms of the same species living in an area is a ______.Intermediate2 pts

Why: One species in one area is a population.

29.The variety of life at genetic, species and ecosystem levels is called ______.Intermediate2 pts

Why: Biodiversity covers genes, species and ecosystems.

30.Organisms that make organic food from inorganic sources are called ______.Intermediate2 pts

Why: Producers (autotrophs) build food from simple inorganic substances, usually using light energy.

31.A proposed explanation that can be tested is a ______.Advanced2 pts

Why: A hypothesis is a testable proposed explanation.

32.The process by which populations change across generations is called ______.Advanced2 pts

Why: Evolution is change in the inherited features of populations over generations.

33.The biological study of interactions between organisms and their environment is called ______.Advanced2 pts

Why: Ecology studies how organisms interact with each other and their environment.

34.A group of different tissues working together to perform a specific function forms an ______.Intermediate2 pts

Why: Tissues combine to form organs, for example the heart or a leaf.

35.A network of interconnected food chains is a ______.Advanced2 pts

Why: Joined food chains make a food web.

Section D — Column Matching

10 marks

Use the ▲ ▼ buttons to reorder Column B until each row lines up with the correct term in Column A. 2 marks per correct pair.

36–40.Match each term in Column A with the correct description in Column B.Advanced10 pts

Column A

Cell

Population

Ecosystem

Homeostasis

Biodiversity

Column B

Regulation of internal conditions

Basic unit of life

Variety of life at multiple levels

Organisms plus their physical environment

Members of one species in an area

Why: Each term pairs with one description: a cell is the basic unit of life; a population is members of one species in an area; an ecosystem is organisms plus their physical environment; homeostasis is regulation of internal conditions; biodiversity is the variety of life at several levels.

Section E — Short Answer

20 marks

5 questions · 4 marks each. Answer in one or two full sentences (at least 8 words). Marks are given for each key idea in the marking guide.

41.Explain two reasons why a cell must regulate what enters and leaves it.Advanced4 pts

42.Distinguish a population, community and ecosystem using one consistent example.Advanced4 pts

43.Explain how natural selection can increase the frequency of an inherited trait without an organism intentionally changing its genes.Advanced4 pts

44.A pond loses much of its plant life. Predict two likely consequences and explain the links.Advanced4 pts

45.Why is evidence from more than one biological level often useful when explaining a complex problem?Advanced4 pts