Biology Quiz for Class 7
Questions: 16 · 10 minutes
1. Where does the chemical digestion of starch normally begin in humans?
In the small intestine, with the action of bile
In the stomach, with the action of hydrochloric acid
In the mouth, with the action of salivary amylase
In the large intestine, with the action of gut bacteria
2. During a fast run, a person’s breathing rate increases. What is the best biological explanation?
The lungs need to digest stored nutrients more quickly
Working cells stop carrying out respiration
The body must reduce blood flow to the muscles
Working cells need more oxygen and produce more carbon dioxide
3. A fish remains underwater while continually moving water across its gills. How do the gills help the fish survive?
They separate hydrogen from water to make food
They store air in the same way as mammal lungs
They absorb oxygen dissolved in the water
They turn carbon dioxide into oxygen
4. A student sorts a frog, fish, bird, and earthworm into vertebrates and invertebrates. Why should the earthworm be placed in the invertebrate group?
It does not have a backbone
It has a long, segmented body
It breathes through moist skin
It lives mainly in soil
5. Under a microscope, a student compares a leaf cell with a human cheek cell. Which structure should normally appear in the leaf cell but not the cheek cell?
Chloroplast
Cytoplasm
Cell membrane
Nucleus
6. A plant’s roots are placed in colored water. Later, the color is visible in the stem and leaf veins. Which tissue carried the colored water upward?
Phloem
Meristem
Epidermis
Xylem
7. Which description best defines a tissue?
Several organs working together
A group of similar cells performing a shared function
A structure found only in plant cells
Every cell contained in one organism
8. Which organ filters the blood to remove urea and excess water when producing urine?
Kidney
Large intestine
Pancreas
Liver
9. A healthy green plant is kept in darkness for several days but still receives water. Which change is most directly caused by the lack of light?
Its roots immediately stop absorbing all water
It makes less glucose through photosynthesis
Its cells lose their cell membranes
It begins taking carbon dioxide from the soil
10. Suppose decomposers suddenly disappeared from a forest ecosystem. Which change would be most likely over time?
Plants would no longer need sunlight
Herbivores would begin producing their own food
Dead material would accumulate and nutrient recycling would slow
Predators would become the main decomposers
11. A student counts 72 pulse beats in one minute while resting. What does the pulse most directly indicate?
The number of breaths taken by the lungs
The speed at which food moves through the intestine
The rate at which the kidneys produce urine
The rhythmic pumping of the heart through the arteries
12. Consider the food chain: grass → grasshopper → frog → snake. Which organism is the primary consumer?
Frog
Grass
Grasshopper
Snake
13. Which cell structure controls what enters and leaves the cell?
Cell wall
Cell membrane
Cytoplasm
Nucleus
14. A clear plastic bag is tied around a leafy branch. Water droplets appear inside the bag after several hours. What best explains the droplets?
Water entered the bag through the plastic
Water vapor left the leaves and then condensed
The leaves produced liquid water during respiration
The branch absorbed water directly from the air
15. A bee carries pollen from the anther of one flower to the stigma of another flower of the same species. What process has occurred?
Pollination
Germination
Seed dispersal
Fertilization
16. What is a main function of stomata in a leaf?
They anchor the leaf to the stem
They transport sugar from leaves to roots
They absorb mineral ions directly from soil
They allow gas exchange and regulate water-vapor loss