Тест: Fundamentals of Plant, Force, and Energy Science — 6 въпроса

1. Which inflorescence type has flowers arranged along an axis and opening in sequence, as seen in stock plants?

A. Simple raceme

B. Simple umbel

C. Simple corymb

D. Compound spike

Answer: (A)

Обяснение

A simple raceme has flowers arranged along an axis that open one after another in sequence. Stock is the example given for this pattern, while a corymb forms a flatter top and an umbel spreads from one point.

2. What is the net force on an object when two opposite forces of 30 N and 20 N act on it?

A. 50 N toward the right

B. 10 N toward the 30 N force

C. 10 N with no direction

D. 0 N because the forces are vectors

Answer: (B)

Обяснение

The net force is found by subtracting opposing forces, so 30 N minus 20 N gives 10 N in the direction of the larger force. Balanced forces would give a net force of zero, which is not the case here.

3. What does a yellow flame from a Bunsen burner indicate?

A. Excess oxygen that makes the flame hotter

B. Complete combustion because the fuel burns fully

C. No combustion because the fuel is absent

D. Incomplete combustion because there is not enough oxygen

Answer: (D)

Обяснение

A yellow flame shows incomplete combustion, which happens when there is not enough oxygen for the fuel to burn completely. A blue flame is the sign of complete combustion.

4. In which lever class is the load positioned between the fulcrum and the effort?

A. Third class lever

B. Compound lever

C. Second class lever

D. First class lever

Answer: (C)

Обяснение

A second class lever has the load between the fulcrum and the effort. This arrangement can save effort when the effort arm is greater than the load arm, giving a mechanical advantage greater than 1.

5. What happens to energy in a reaction when chemical bonds form?

A. Energy is released to the surroundings

B. Energy is destroyed in the process

C. Energy stays in the same form

D. Energy is absorbed from the surroundings

Answer: (A)

Обяснение

Forming chemical bonds is an exothermic step, so energy is released to the surroundings. Breaking chemical bonds, by contrast, is endothermic because it absorbs energy.

6. Which flower part is the pollen-producing structure, and which symbol is used to represent the flower type?

A. Anther; ⚥

B. Ovary; ♂

C. Petal; ★

D. Sepal; ♀

Answer: (A)

Обяснение

The anther is the pollen-producing part of the flower, and the source uses the symbol ⚥ to represent the flower type. The ovary, sepal, and petal have different functions.