Biology Quiz for Class 10
Questions: 16 · 10 minutes
1. A person touches a hot pan and withdraws a hand before consciously registering the pain. Which structure acts as the first major coordinating center for this response?
Cerebrum
Cerebellum
Medulla oblongata
Spinal cord
2. A plant is placed with its roots in colored water. Later, the color appears in the veins of its leaves. Which tissue carried most of this water upward?
Phloem
Cambium
Epidermis
Xylem
3. In pea plants, tallness (T) is dominant over dwarfness (t). What offspring ratio is expected from the cross Tt × tt?
All tall
One tall to one dwarf
Three tall to one dwarf
All dwarf
4. Which method of asexual reproduction is commonly used by Amoeba?
Vegetative propagation
Budding
Spore formation
Binary fission
5. A young shoot receives light mainly from one side and bends toward it. Which explanation best accounts for this response?
Auxin accumulates on the lit side and stops all growth there
Auxin promotes greater cell elongation on the shaded side, causing the shoot to bend toward the light
Chlorophyll moves to the shaded side and pulls the shoot toward the light
Water moves only to the lit side, making those cells shorter
6. Which raw material for photosynthesis enters a leaf mainly through its stomata?
Carbon dioxide
Oxygen
Glucose
Chlorophyll
7. What is the main biological importance of the ozone layer?
It traps all heat leaving Earth
It supplies oxygen directly for cellular respiration
It absorbs much of the Sun's harmful ultraviolet radiation
It converts atmospheric nitrogen into plant nutrients
8. Which feature of the alveoli most directly supports rapid gas exchange in the lungs?
They contain cartilage rings that prevent collapse
They produce digestive enzymes for absorbed nutrients
They provide a large, thin, moist surface with a rich blood supply
They have thick walls that keep gases separated
9. In humans, why is the sperm cell described as determining whether an embryo is genetically XX or XY?
Every sperm carries both an X and a Y chromosome
An egg carries X, while a sperm can contribute either X or Y
The sperm changes the egg's X chromosome after fertilization
The egg can carry either an X or a Y chromosome
10. A destarched plant has part of one leaf covered with opaque paper. After several hours in sunlight, the leaf is tested with iodine. What result is expected?
The exposed part turns blue-black, while the covered part stays pale
The covered part turns blue-black, while the exposed part stays pale
Both the covered and exposed parts turn blue-black
Both parts stay pale because the plant was previously destarched
11. Which enzyme begins the digestion of proteins in the stomach?
Amylase
Pepsin
Lipase
Trypsin
12. Which contraceptive method can help reduce the likelihood of both pregnancy and transmission of many sexually transmitted infections when used correctly?
Condoms
Oral contraceptive pills
An intrauterine device
Surgical sterilization
13. Grass stores 10,000 joules of energy. Using the approximate 10% transfer rule, how much energy would be available to a frog in the chain grass → grasshopper → frog?
10 joules
1,000 joules
100 joules
9,000 joules
14. A persistent pesticide enters an aquatic food chain: algae → zooplankton → small fish → fish-eating bird. In which organism is the pesticide likely to reach the highest concentration through biomagnification?
Fish-eating bird
Algae
Zooplankton
Small fish
15. Why do breathing rate and heart rate usually rise during vigorous exercise?
The lungs must lower the amount of energy released by cells
Muscles stop using glucose and begin producing oxygen
Muscles need faster oxygen delivery and carbon dioxide removal as respiration increases
The heart temporarily takes over the lungs' gas-exchange function
16. What would most likely happen over time if decomposers disappeared from a forest ecosystem?
Producers would immediately obtain more mineral nutrients from the soil
Consumers would begin making their own food by photosynthesis
Dead matter would vanish faster because predators would consume it
Dead matter would accumulate and nutrient recycling would slow greatly