Biology 2005 Jamb Examination

D. shivering in a cold environment

Shivering is a homeostatic response, because it helps regulate body temperature. When the environment is cold, involuntary muscle contractions generate heat, maintaining the body’s internal temperature.

The other options are reflex actions or conditioned responses, not mechanisms of homeostasis.

C. 24 °C

From the graph, you can observe how cockroach numbers change over time at different temperatures:

• At 15 °C, the population rises very slowly and never exceeds around 100 before declining—clearly not optimal.

• At 19 °C, there’s a moderate growth, peaking at about 200 cockroaches before plateauing.

• At 24 °C, population growth is most dramatic: cockroach numbers surge past 400, reaching the highest level among the temperatures shown.

• At 33 °C, while initial growth is rapid and surpasses that at 19 °C for a time, it doesn’t reach the same zenith as at 24 °C and begins to decline sooner.

Therefore, the optimal temperature for breeding cockroaches—where their population grows highest and fastest—is clearly 24 °C, so the correct answer is:

From the diagram, after 10 days:

• At 15 °C, cockroaches hardly increase in number and their population declines sharply — they do not survive beyond this point.

• At 19 °C, 24 °C, and 33 °C, their populations are still present and relatively higher compared to 15 °C.

So, the temperature at which cockroaches will not survive after 10 days is:

A. 15 °C

Correct Answer: Option A

Evaporation is taking place in the part labelled I as the ocean is being evaporated to the cloud.

Transpiration which takes place in the leaves of the plants is taking place in the part labelled II.

D. ocean

While clouds are a crucial part of the water cycle, acting as a temporary storage location for water, they are not considered the major reservoir in the water cycle; that distinction belongs to the oceans. The oceans are by far the largest reservoir, holding about 97% of Earth's water. 

C. Taraba state

The Mambila Plateau is a distinct Nigerian biome found in Taraba State, known for its high elevation, cool climate, and rich biodiversity.

B. rainforests and the sudan savanna

In Nigeria, the Guinea savanna belt lies between the southern rainforests and the northern Sudan savanna, serving as a transitional vegetation zone.

Correct answer: D. 200000

Side of farmland = 200 m
Area of farmland = 200 × 200
= 40,000 m²
Density = 5 plants per m²

Population size = Density × Area
= 5 × 40,000 = 200,000

B. soil is already present

Secondary succession proceeds faster because the area has been previously occupied, so soil, organic matter, and nutrients are already available, unlike in primary succession where soil must first develop on bare surfaces like rocks.

C. HCl(aq)

The presence of lime (CaCO₃) in soil is tested by adding dilute hydrochloric acid. If lime is present, the reaction releases carbon (IV) oxide gas with effervescence:

CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂ ↑

This fizzing confirms the presence of lime.