Grade 10 Biology practice questions – Lebanese curriculum

Q: Where do these Grade 10 Biology questions come from?

They are a sample from EduRise's Grade 10 Biology question bank (1,064 questions across 10 chapters), written to follow the Lebanese curriculum. Each chapter on EduRise has its own practice set and a timed exam.

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Question 1

Which of these organisms is autotrophic?

Accepted Answer

a green alga. A green alga contains chlorophyll and builds its organic matter by photosynthesis.

Question 2

In an experiment, elodea, lit by a lamp, releases 26, 27 and 28 bubbles of gas in three successive minutes. What is the mean rate of bubbling (bubbles per minute)?

Accepted Answer

27. Mean = (26 + 27 + 28) ÷ 3 = 81 ÷ 3 = 27 bubbles/min.

Question 3

Why are absorbing hairs efficient?

Accepted Answer

they are very numerous and give a huge contact surface with the soil solution. Thousands of thin-walled hairs greatly increase the absorbing surface.

Question 4

In an experiment, cobalt chloride paper turns from blue to pink in 3 min on the lower surface of a leaf and in 15 min on the upper surface. Which conclusion is correct?

Accepted Answer

the lower surface loses water vapour about 5 times faster, having more stomata. 15 ÷ 3 = 5: the paper becomes moist 5 times faster underneath, where most stomata are.

Question 5

What is the main reserve of walnut kernels?

Accepted Answer

lipids. The main reserve of walnut kernels is lipids, shown by Sudan III (red-orange stained droplets).

Question 6

An unknown plant-organ extract is tested with Sudan III. Result: red-orange stained droplets. Which substance does it contain?

Accepted Answer

lipids. Sudan III → red-orange stained droplets: this reveals lipids.

Question 7

On an oscilloscope, an axon is at −80 mV at rest and its action potential peaks at +40 mV. What is the amplitude of the action potential?

Accepted Answer

120 mV. Amplitude = peak − resting = 40 − (−80) = 120 mV.

Question 8

On an oscilloscope, an axon is at −70 mV at rest and its action potential peaks at +35 mV. What is the amplitude of the action potential?

Accepted Answer

105 mV. Amplitude = peak − resting = 35 − (−70) = 105 mV.

Question 9

A goitre is:

Accepted Answer

an enlargement of the thyroid gland. A goitre is a visible swelling of the neck due to a bigger thyroid.

Question 10

What is the target of thyroxine?

Accepted Answer

almost all the cells of the body. Thyroxine is secreted by the thyroid into the blood and acts on almost all the cells of the body, whose cells have its receptors.

Question 11

How is a pure line obtained?

Accepted Answer

By self-pollinating plants for several generations. Repeated self-pollination makes the plants homozygous: they then give offspring identical to themselves.

Question 12

Document: A bud of a chosen apple variety is inserted under the bark of a wild apple seedling and tied. Which technique is described?

Accepted Answer

grafting. This is grafting, a method of vegetative propagation: the fruit-bearing scion keeps the genes of the chosen variety and the rootstock provides the roots.

Question 13

What is hydroponics?

Accepted Answer

Growing plants without soil, their roots in a nutrient solution. The solution contains water and all the mineral salts; the soil is replaced by the solution or an inert support.

Question 14

Document: in an experiment at constant strong light and CO₂, cucumber leaves produce O₂ (a.u.) at 5, 10, 15, 20, 25, 30, 35, 40, 45 °C: 1, 6, 16, 33, 51, 59, 40, 12, 2. What is the optimal temperature for photosynthesis?

Accepted Answer

30 °C. The highest production (59 a.u.) is at 30 °C.

Question 15

Which of these is a physical indicator of water quality?

Accepted Answer

Turbidity. Temperature, turbidity, colour and odour are physical; DO and nitrates are chemical; the biotic index is biological.

Grade 10 Biology Questions and Answers

15 Grade 10 Biology practice questions

1. Which of these organisms is autotrophic?

2. In an experiment, elodea, lit by a lamp, releases 26, 27 and 28 bubbles of gas in three successive minutes. What is the mean rate of bubbling (bubbles per minute)?

3. Why are absorbing hairs efficient?

4. In an experiment, cobalt chloride paper turns from blue to pink in 3 min on the lower surface of a leaf and in 15 min on the upper surface. Which conclusion is correct?

5. What is the main reserve of walnut kernels?

6. An unknown plant-organ extract is tested with Sudan III. Result: red-orange stained droplets. Which substance does it contain?

7. On an oscilloscope, an axon is at −80 mV at rest and its action potential peaks at +40 mV. What is the amplitude of the action potential?

8. On an oscilloscope, an axon is at −70 mV at rest and its action potential peaks at +35 mV. What is the amplitude of the action potential?

9. A goitre is:

10. What is the target of thyroxine?

11. How is a pure line obtained?

12. Document: A bud of a chosen apple variety is inserted under the bark of a wild apple seedling and tied. Which technique is described?

13. What is hydroponics?

14. Document: in an experiment at constant strong light and CO₂, cucumber leaves produce O₂ (a.u.) at 5, 10, 15, 20, 25, 30, 35, 40, 45 °C: 1, 6, 16, 33, 51, 59, 40, 12, 2. What is the optimal temperature for photosynthesis?

15. Which of these is a physical indicator of water quality?

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