Put forward the question: according to the knowledge learned, eating fruits and vegetables often can prevent scurvy and enhance the body's immunity, because fresh fruits and vegetables are rich in vitamin C. but the nature of vitamin C is not stable enough, high temperature cooking, long-term storage and so on are easy to be damaged. As a common vegetable, can cucumber be eaten raw or cooked to make the human body absorb more vitamin C What about vitamin C? Make a hypothesis: your hypothesis:______ Make a plan: ① take two equal portions of cucumber, boil one portion of them, make juice respectively, and pour them into two small beakers. ② take two clean and dry small tubes No. 1 and No. 2, respectively, and inject 2ml of potassium permanganate solution of different concentrations, absorb the juice of raw cucumber with a dropper, and drop it into tube No. 1 drop by drop, while shaking and observing, until the color of potassium permanganate solution fades (3) then use the same dropper to absorb the juice of ripe cucumber, drop it into test tube No. 2, shake and observe the color of potassium permanganate solution until the color fades, and record the number of drops of juice (m)______ ．（2）______ Implementation plan: carry out the experiment according to the revised plan, count and analyze the experimental phenomena. Conclusion: Please predict the three experimental results and draw the corresponding conclusions (3)______ ．（4）______ ．（5）______ ．

Put forward the question: according to the knowledge learned, eating fruits and vegetables often can prevent scurvy and enhance the body's immunity, because fresh fruits and vegetables are rich in vitamin C. but the nature of vitamin C is not stable enough, high temperature cooking, long-term storage and so on are easy to be damaged. As a common vegetable, can cucumber be eaten raw or cooked to make the human body absorb more vitamin C What about vitamin C? Make a hypothesis: your hypothesis:______ Make a plan: ① take two equal portions of cucumber, boil one portion of them, make juice respectively, and pour them into two small beakers. ② take two clean and dry small tubes No. 1 and No. 2, respectively, and inject 2ml of potassium permanganate solution of different concentrations, absorb the juice of raw cucumber with a dropper, and drop it into tube No. 1 drop by drop, while shaking and observing, until the color of potassium permanganate solution fades (3) then use the same dropper to absorb the juice of ripe cucumber, drop it into test tube No. 2, shake and observe the color of potassium permanganate solution until the color fades, and record the number of drops of juice (m)______ ．（2）______ Implementation plan: carry out the experiment according to the revised plan, count and analyze the experimental phenomena. Conclusion: Please predict the three experimental results and draw the corresponding conclusions (3)______ ．（4）______ ．（5）______ ．

Hypothesis: the hypothesis is actually a positive answer to the question, so there are two kinds of answers: raw cucumber can take in more vitamin C or cooked cucumber can take in more vitamin C

Final test questions of biology in grade one of junior high school

Final simulated test questions of biology Volume 1 of Grade 7
One choice (2 points for each question, 40 points in total)
1. Which of the following characteristics is not common to all living things ()
A. respiration B. need nutrition C. composed of cells D. growth and reproduction
2. The structure of both plant cells and animal cells is ()
A. vacuole B. chloroplast C. cell wall D. mitochondria
3. The following food chain is correct ()
A. grass → rat → snake → Eagle B. Eagle → snake → rat → grass
C. grass, rat, snake, Eagle D. eagle, snake, rat, grass
4. If the image seen in the field of vision of the microscope is located at the lower right of the field of vision, how to move the slide so that the image can be located in the center of the field of vision
A. move the slide to the upper left B. move the slide to the lower right
C. move slide down left D. move slide up right
5. The following non ecosystem is ()
A. a field B. a pond C. all the fish in Jialing River D. biosphere
6. Which of the following organisms can monitor air pollution ()
A. kelp B. Cucurbitaceae C. Guanzhong D. Manjianghong
7. The following non unicellular organisms are ()
A. Chlamydomonas B. Spirogyra C. Paramecium D. amoeba
8. What is the origin of seed plant seedlings
A. seed coat B. cotyledon C. embryo D. endosperm
9. Which of the following groups of microscopes can see the least cells ()
　　A.10×、4× B.10×、10× C.16×、10× D.16×、40×
10. It is ()
A. onion epidermis B. tomato peel C. leaf epidermis D. leaf vein
11. The site of photosynthesis is ()
A. mitochondria B. chloroplast C. cell wall D. vacuole
12. Human ears, eyes and heart belong to ()
A. tissue B. organ C. system D. new cell
13. Some Luffa flowers don't bear fruit because of the lack of flower structure ()
A. stamens B. pistils C. sepals D. petals
14. In the experiment of "green leaves make organic matter under light", the purpose of putting potted geranium in the dark for a day and a night is ()
A. consumption of water in leaves B. consumption of organic matter in leaves
C. consumption of chlorophyll in leaves D. consumption of inorganic salts in leaves
15. Some lawless elements steal the bark of Eucommia ulmoides Oliv as medicinal materials, causing the trees to die. This is mainly because what structure in the bark has been damaged ()
A. sieve tube B. duct C. medulla D. cambium
16. Among the following vegetation types, the most abundant plant species is ()
A. grassland B. tropical rain forest C. evergreen broad leaved forest D. deciduous broad leaved forest
17. Among the following organisms, ()
A. fungi B. bacteria C. viruses D. yeasts
18. The result of cell differentiation is the formation of ()
A. tissue B. organ C. system D. individual
19. Chameleon can change its body color according to its surroundings
A. organisms can change the environment B. organisms can adapt to the environment
C. organisms depend on the environment D. bioenergy affects the environment
20. When raising fish, planting water plants on the bottom of the fish tank is mainly for ()
A. make the fish tank look good B. increase the number of organisms in the fish tank
C. increase oxygen in fish tank D. increase nutrients in fish tank
2. Fill in (1 point for each blank, 20 points in total)
The results are as follows: 1. Tissue mainly exists in root tip and bud of plant; epidermis of leaf mainly consists of tissue
2. Many kinds of inorganic salts are needed in plant life, among which the most needed are contained, contained and contained inorganic salts
3. Respiration is completed in living cells; photosynthesis is completed in living cells
4. The part of root absorbing water is mainly apical. There are a lot of water in this area. The fastest growing area of apical is
5. According to the living environment of organisms, we can divide them into two categories: and
6. When we eat watermelon, we will see a lot of juice flowing out from the cell structure; the structure that plays a protective and supporting role in plant cells is
7. The carrier of genetic information in nucleus is
8. The virus has no cell structure, it is composed of outer shell and inner part
9. The basic unit of structure and function of organism is
10. Organisms grow up from small to large because of and
Distinguish right from wrong (10 points in total)
1. There are vessels in the roots, stems and leaves of plants
Virus is harmful to human beings but not beneficial
3. The structure of a flower must include stamens and pistils
Living things can adapt to and change the environment
5. The green part of the plant can carry out photosynthesis
6. The respiration of plants only takes place at night
7. The plant body of green flowering plant is composed of six organs: root, stem, leaf, flower, fruit and seed
A complete bone belongs to tissue
9. Ecosystem is composed of producers, consumers and decomposers
10. Toxic substances will flow and pass along the food chain and food web
4. Recognition map (10 points in total)
1. (please fill in the number of the corresponding structure on the line. 5 points in total)
The embryo of corn seed is composed of; the embryo of kidney bean seed is composed of
2. Endosperm; pericarp and testa; testa
2. Please fill in the structure shown in the figure below on the horizontal line. (5 points in total)
In the structural diagram of blade, 12 is, 13 is, 14 is, 15 is, 16 is
5. Talk about it (5 points)
In 1884, hyacinth (also known as water hyacinth), native to Venezuela, South America, was sent to the New Orleans fair in the United States. People from all over the world saw its gorgeous flowers and brought them back to their respective countries as ornamental plants. However, the highly prolific Eichhornia crassipes have become a big headache for people all over the world, Eichhornia crassipes are found all over the Nile River; in Thailand, Eichhornia crassipes are found all over the Mekong River; and the inland waterways along the Gulf of Mexico in the south of the United States are blocked by dense layers of Eichhornia crassipes, which not only makes ships impassable, but also leads to the disappearance of fish and shrimp, and the river stinks; and Dianchi Lake in Yunnan, China, was once accused of suffering from "ecological cancer" because of the crazy spread of water hyacinth
Read the above material, please use your knowledge to analyze the phenomenon in this material
6. Classification (5 points in total)
The above picture shows the creatures Xiao Ming surveyed around him. Please classify them in two different ways
7. Do and do (10 points in total)
We often eat garlic yellow in our life. The reason why it appears yellow and white is that it grows in the dark and lacks chlorophyll in leaf cells. Please design an experiment to explore the conditions for the formation of chlorophyll
Materials: garlic yellow
Asking questions: (1 point)
Make a hypothesis: (1 point)
Plan making: the variable in the experiment is. (1 point)
Method steps (2 points)
Results of conditional experiments
Experimental group
Control group
Conclusion: (1 point)

The first year of junior high school~~
In the experiment of exploring the influence of light on the life of the rat woman, a control experiment was used, that is, when studying the influence of a condition on the research object, all the experiments except for the one not used were the same. In the experiment of exploring the influence of light on the life of the rat woman, a layer of wet soil was placed in the iron plate, with the middle line of the horizontal axis as the boundary, and a cardboard was covered on one side, The other side is covered with a glass plate. In this way, two kinds of environments, bright and dark, are formed in the plate. That is to say, the variables of this experiment are, constant, and soil moisture

Experimental variables and other conditions
Light temperature

How to solve the equation 2x = 52 + 4 (80-x)... I'll wait

2x=52+4(80-x)
2x= 52 + 4* 80 - 4x
2x+4x = 52 + 320
6x = 372
x=62

Train a is going from a to B at a speed of 150 km / h. one hour later, train B is going from B to a at a speed of 70 km / h. If a and B are 200 km apart, how far is the meeting point from a?

One hour later, Party A and Party B met
[200 - (150 * 1)] / (150 + 70) = 5 / 22 hours
The distance from ground a is 150 * (1 + 5 / 22) = 150 + 375 / 11 ≈ 150 + 34.10 = 184.10km

Solution equation: (x + 2 / x + 1) + (2x + 9 / x + 4) = (x + 4 / x + 3) + (2x + 5 / x + 2)

The original equation is transformed into
1+1/x+1+2+1/x+4=1+1/x+3+2+1/x+2
That is 1 / x + 1 + 1 / x + 4 = 1 / x + 3 + 1 / x + 2
That is, 2x + 5 / (x + 1) (x + 4) = 2x + 5 / (x + 3) (x + 2)
That is, (x + 1) (x + 4) = (x + 3) (x + 2)
If 2x + 5 ≠ 0, the equation has no solution
∴2x+5=0
x=-5/2

Two cars are traveling from station a and station B at the same time. Car a travels 54 kilometers per hour and car B travels 48 kilometers per hour. When car a meets car B, car a travels 30 kilometers more than car B. when car a meets car B, car B runs 48 kilometers per hour
When meeting, car a travels 30 kilometers more than car B. 1 find the time of meeting, 2 find the distance between two places
A complete method for solving formulas and equations

One hour Jiaduo 54-48 = 6 km
More than 30 kilometers
So the meeting time is 30 △ 6 = 5 hours
The distance is (54 + 48) × 5 = 510km

If there is a one place decimal, remove its decimal point and add it to the original number, the sum is 40.7. What is the one place decimal?

A decimal, its decimal point removed, is to expand the original number ten times
So, the original number is 40.7 / (1 + 10) = 3.7

A passenger car and a freight car depart from Nanjing and Huai'an at the same time. The passenger car runs 56 kilometers per hour and the freight car 48 kilometers per hour
The two cars meet 32 kilometers from the midpoint. How many kilometers are there between the two places?

32 × 2 ÷ (56-48) = 8 hours, then the two vehicles meet when driving for 8 hours
8 × (56 + 48) = 832km
A: the distance between the two places is 832 km

Finding the common tangent equation of circle C1: x ^ 2 + y ^ 2 = 4 and circle C2: (x-3) ^ 2 + y ^ 2 = 1

The vertical tangent of C1 has x = - 2, or x = 2, where x = 2 is also the tangent of C2, so x = 2 is the common tangent, and the horizontal tangent of C1 has y = - 2 or y = 2, neither of which is the tangent of C2. Suppose that the inclined tangent is y = KX + B, and the distance from the center of two circles to this tangent is radius respectively, that is: C1: | B | / √ (k ^ 2 + 1) = 2c2: | 3K + B | / √ (k ^ 2 + 1) = 1