The science course of Zhejiang Education Edition is a comprehensive course in junior high school, so what are the problems that are easy to make mistakes? Next, I sorted out the easy-to-mistake questions and answers of science in the next semester of Grade 8 for you. Let's have a look.

Eight scientific error-prone topics Zhejiang Education Edition 1 1. In the following plant groups, the same group as soybean root system is ().

A. Barley, onions and sugar cane B. Corn, carrots and leeks

C apples, cabbages and camphor trees, green bristlegrass, rice and sorghum

2, water eutrophication pollution occurs, a large number of aquatic animals such as fish died because ()

A. There are too many nitrogen and phosphorus nutrients in the water. B. A large number of algae plants died.

C. the dissolved oxygen in the water body decreases sharply. D. microorganisms in the water body multiply in large numbers.

3, the following uses of salt water and the main function of salt water can't correspond to ().

A, when making kimchi, vegetables are soaked in salt water to maintain normal cell morphology.

B rinse your mouth with salt water when you have a cold and disinfect it.

C. After working at high temperature, people should drink some light salt water to maintain the balance of water and salt metabolism in the body.

D, making oral epithelial cells with 0.9g% physiological saline to maintain the normal morphology of the cells.

4. Waste water discharged from dismantling plant is the most likely to cause biological pollution of soil ().

A. Slaughterhouse B. Chemical plant C. Electroplating plant D. Paper mill

5. The stems of woody plants are () from outside to inside.

A. Bark, phloem, cambium, xylem and pith

B. Bark, xylem, cambium, phloem and pith

C. bark, xylem, cambium, pith,

D. bark, cambium, xylem and pith

6. When rubber latex is collected, rubber trees are often cut. In order to make the latex flow out smoothly, the correct rubber cutting method is to cut to which part of the rubber tree ().

A. xylem: phloem of inner bark

C. phloem of outer bark

7, the object is affected by the opening and closing of pores in the following activities is ()

① Moisture absorption and transportation; ② Transport function of inorganic salts; ③ Photosynthesis; ④ respiration; ⑤ Transpiration

A.①②④⑤ B.②③④⑤

C.①②③④ D.①②③④⑤

8. Wang Fang found that there are five annual rings on the cross section of the stems of plants growing in the wild, and the annual rings in the middle are very narrow. Visiting the local people, I learned that there is abundant precipitation and high temperature all the year round. The most likely reason for the extremely narrow plant rings is ().

A. Drought B. Temperature

C. locust plague D. lack of inorganic salts for plant growth

9. For green plants, photosynthesis will increase with the increase of light, but when the clear sky is full of sound clouds and strong sunlight, the photosynthetic efficiency of plants will decrease around noon. Lunch break phenomenon? . The reason is ()

First, transpiration is too strong, and the body is short of water.

B, the activity of the enzyme is reduced so that it loses its activity.

C, stomata closed, insufficient CO2 intake.

D. The pores are closed, and the release of O2 is blocked.

10, the time for plants to breathe is ()

A. Day B. Night C. When there is light D. Day and night

1 1, and the expression of breathing process is ()

A. water+carbon dioxide+energy? Organic matter+oxygen+energy

B. oxygen+organic matter-carbon dioxide+water+energy

C. Organic matter+carbon dioxide monohydrate+oxygen+energy

Water+oxygen-organic matter+carbon dioxide+energy

12, which of the following is relevant? Does the soil contain organic matter? In the verification experiment, the error is ()

A. the soil should be dry enough.

B. The soil should be rich in organic matter.

C. the aperture of barbed wire should be small in the experiment.

D. When drying the soil, barbecue directly on the fire.

13. There is lunar soil on the surface of the moon. Lunar soil is mainly composed of lunar rock fragments, powder, breccia and materials that impact molten glass, most of which are between 30 microns and 1 mm, and feel as fine as flour. But not suitable for plant growth. Scientists imagine that when humans immigrate to the moon, they will transform the lunar soil into soil similar to that on the earth to cultivate plants. In the process of transformation, what is not needed is ()

A. air B. water C. corrosiveness D. minerals

14, the following factors, the most significant influence on the average length of plant roots is ().

A.b. Proportion of mineral particles

C. Content of organic matter in soil D. Content of inorganic salts in soil

15, using the characteristics of plant root growth and distribution, planting trees and grass on sloping land and sandy land with harsh environment, the main purpose is ()

A. Greening environment B. Soil and water conservation

C. Grazing livestock D. Obtaining wood

16, in the root tip structure, there is a group of approximately square cells, which are closely arranged, with thin cell wall, thick cytoplasm and large nucleus. These cells are located in ().

A. Root cap B. Divergent area C. Elongated area D. Root hair area

17, the roots of plants grow in the soil, so they can't make organic matter through photosynthesis. The fundamental reason why the root system can't carry out photosynthesis is ()

A. root cells can't absorb water

B. root cells have no chloroplasts.

C. root cells are enclosed in soil and cannot get sunlight.

D. root cells can't absorb carbon dioxide

18, the following does not belong to the characteristics of root meristem cells is ()

A. the cells are very small. B. High cytoplasmic concentration

C. cells can divide constantly. D. cells grow rapidly.

19, the following four groups of the same plant cultured under different experimental conditions, the largest stomatal opening of leaves should be ().

20, after plant irrigation, stomatal opening and closing and transpiration should be ()

A. stomata are closed and transpiration is enhanced. B. when stomata are opened, transpiration is weakened.

C. when stomata are opened, transpiration is enhanced. D. stomata are closed and transpiration is weakened.

2 1, about human respiration, the following statement is wrong ()

A. Exhale and inhale depend on the activities of diaphragm and intercostal muscle.

B. When breathing, the inhaled air can exchange gas in the lungs.

C. when inhaling, the external air pressure is greater than the air pressure in the lungs.

D, lung gas exchange is completed in alveoli.

22, the significance of the ozone layer to life on earth lies in ()

A.it can absorb too much heat from the sun.

B can help keep the earth warm.

C can absorb most ultraviolet rays from the sun, and D can produce oxygen needed by living things.

23. where is it Observing soil organisms? In the activity, soil with flowers and crops should be selected as samples, because ()

A. only in this soil can there be life.

B.it is easy to find all kinds of creatures in this soil.

C. the soil is loose and easy to sample.

D. The soil contains more water and air.

24, loam soil is suitable for the growth of most plants, the solid part of the soil accounts for about () of the total soil volume.

a、 15% B、30% C、50% D. 95%

25. Sugarcane in Yiwu is squeezed from sugarcane. If you want to harvest sugar cane, you should usually apply more ().

A. Potassium fertilizer B. Nitrogen fertilizer C. Phosphorus fertilizer D. Calcium fertilizer

26, too much fertilization at a time in the farmland, crops will wilt phenomenon, the best solution is ().

Science is easy to make mistakes. Eight answers to Zhejiang Education Edition II A. Increase light B. Water a lot C. Loosen soil D. Reduce light

27. Sewage discharged from hospitals is the most likely to cause () soil.

A. Chemical pollution B. Salinization C. Biological pollution D. Heavy metal pollution

28. The following practices about the development and utilization of soil resources are wrong ()

A. Developing urban wetlands into residential quarters

B, the use of tidal flats for aquaculture.

B. Planting trees to reduce soil desertification

D it is forbidden to use clay to fire solid building bricks.

Soil salinization will seriously affect the quality of cultivated land and lead to crop yield reduction. The root cause of crop yield reduction after salinization is ()

The soil lacks inorganic salts.

B. the soil is short of water and cannot be swallowed.

C. The concentration of soil solution is too high, making it difficult for plants to absorb water.

D. the soil is hardened, and it is difficult for plant roots to get air.

30 alveolar gas exchange is achieved by which of the following ()

A. respiration, respiratory movement, diffusion and infiltration

3 1 The part that plants can breathe is ()

Any living part

The following statement about breathing is incorrect ()

A. as long as there are living cells; You can breathe.

B. Breathing can be done with or without light.

C. respiration provides raw materials for photosynthesis of plants.

D the heat released by respiration is an indispensable power for plants to carry out various physiological activities.

Shenzhen put it forward by itself? Building an eco-city, a green dream? After the slogan was put forward, the forest coverage rate increased rapidly, and according to statistics, it has reached 43.4% at present. The following about the function of green plants, narrative error is ()

Photosynthesis synthesizes organic matter, releases oxygen and provides food and oxygen for humans and other animals.

B transpiration promotes the root system to absorb water and participate in the water cycle in nature.

C photosynthesis converts solar energy into chemical energy and stores it, which realizes the energy conversion. Photosynthesis only occurs during the day, and respiration only occurs at night.

20 12 On March 25th, Zhejiang Environmental Protection Department began to report the new air pollution index project ().

Sulfur dioxide inhalable particulate matter

C.PM2.5 D carbon monoxide

Dead organisms in the soil finally decompose into inorganic substances, mainly because (a) is the result of oxygen oxidation in the soil, b is eaten by small animals, c is decomposed by microorganisms, and d is the result of plant respiration.

About soil, the following statement is incorrect ()

A. Soil consists of mineral particles, organic matter, water and air.

B. the solid part of the soil is mainly composed of organic matter.

C mineral particles account for 95% of the solid part. The air in the soil is the source of oxygen for plant roots to breathe.

The formation of soil is a long and complicated process, and the following statement about the causes of soil formation is incorrect ()

A. Rock weathering is a necessary condition for soil formation.

Biological activities play an important role in the process of soil formation.

C. the products of rock weathering gradually develop into soil.

Rock becomes soil through physical changes such as thermal expansion and contraction.

When doing soil seepage experiment, the same condition that must be controlled is ().

① The volume of sand and clay used is the same; (2) the water quantity must be the same; ③ The time of water seepage should be exactly the same.

④ The absorbent cotton put into the funnel should be the same; ⑤ The conical bottles should all be the same size.

A.①②③④⑤ B.①②②④

C②③④⑤ D②③④

Among the following soils, () has the best water retention performance.

A. Sandy soil B. Clay

C. loam d cannot be determined.

What should farmers do during the growth and development of rice? Aside from the field? , "put aside the field? It is to dig a deep ditch around the paddy field, drain the water in the field and dry the soil. The following and? Aside from the field? What is irrelevant is ()

Coordinate the balance of soil moisture and air.

B. promoting the respiration of rice roots

C. controlling the wild growth of rice leaves

D. promoting photosynthesis of plants

4 1 In the following groups of plants, the same as soybean root system is ()

Barley, onions, sugar cane, kidney beans, carrots and leeks

C taro, Chinese cabbage, sweet potato, banana, green beans and cauliflower

42 in apical structure; There is a group of approximately square cells, closely arranged, with thin cell wall, thick cytoplasm and large nucleus, which can be elongated. These cells are located in the meristem area of () a root crown b.

C. Elongation zone D. Root hair zone

43 the following conditions will not lead to water eutrophication is ()

A discharges domestic sewage at will, and B uses a lot of chemical fertilizers and pesticides.

C straw is naturally decomposed in farmland, and D slaughterhouse sewage is discharged at will.

Experiments show that plants need inorganic salts besides water, and different inorganic salts have different effects on plant growth. When plants lack potassium, the most likely symptom is ()

A is short with brown spots on her leaves. B is short and has yellow leaves.

C. The leaves are dark green, with red D, which only blooms but does not bear fruit.

Among the following factors, () is related to the formation of annual rings in the cross section of perennial trunks.

The age of the tree is easy to remember.

B. Periodic changes of temperature, humidity and sunlight

C. erosion of water transported through tree trunks

The alternating arrangement of two kinds of cells that transport water and nutrients.

If the bark is cut, the leaves at the top of the cutting ring will ()

A can get water, but not inorganic salts. B can get inorganic salts, but not water.

C can get both water and inorganic salts. D neither water nor inorganic salts can be obtained.

The following is the process of plant death after annular peeling of dicotyledonous woody stems. The correct order is ().

(1) Leaf cell death; ② Root cell death; ② Water transportation is blocked; (4) nutrient transportation is blocked.

A.①②②④B②③①④c .④②①D④②③①

48 floating plants such as duckweed and Azolla, whose leaves float on the water, should be () without pores.

When observing the stomatal structure, first find the guard cells with low power microscope. If the guard cell is located at the upper right of the field of view, move the image of the guard cell to the center of the field of view before observing it with high magnification. At this point, the film should be loaded to ().

Move to the left B. Move to the right

C. Move to the lower left corner D. Move to the lower right corner

In hot summer, there are boards, stones and steel pipes on the grass, and the lowest temperature is ().

A grass b wood c stone d steel pipe

5 1 can provide food for soil animals and nutrients for green plants ()

A moisture b air c inorganic salt d humus

In the root structure, the main factor that drives the root system to grow into the soil is ().

A, root cap, b, meristem area, c, elongation area, D. The above three factors are the main factors.

Sun Wu wants to do an experiment to verify the transpiration of plants. There are several kinds of plants to choose from. In order to make the experiment most effective, he should choose ().

A geranium b cactus c cedar d kelp

& gt& gt& gt More answers to eight wrong questions in science on the next page?