7 grade Science notes Unit 2 Transportation in human and plants PTB

7 grade Science notes Unit 2 Transportation in human and plants PTB

Class 7 Unit NO . 2 Transportation in Human and plants (PTB)

1. What is meant by transportation?
Ans: The supply of food, water oxygen, etc., and the removal of wastes from our body is called transportation. 

2. What do you mean by oxygenated blood?
Ans: The blood rich with oxygen is called oxygenated blood.
3. What is the estimated size of our heart?
Ans: Our heart is a muscular organ that pumps blood continuously. The size of our heart is about the size of our fist.

4. Which arteries carry deoxygenated blood from the heart to the lungs?

Ans: Pulmonary arteries carry deoxygenated blood from the heart to the lungs.
5. Write the names of at least two diseases that can damage our kidneys.
Ans. Blood pressure and diabetes are diseases that can damage our kidneys.
6. Which tissue does transport water in plants?
Ans: Xylem tissue does transport water from roots to leaves in plants.
7. Name three parts of the circulatory system.
Ans: 1. Heart 2. Blood 3. Blood Vessels
8. Can you explain why it is important to circulate blood through the body?
Ans: During circulation, blood transports food and oxygen to every cell of the body. Carbon dioxide and waste materials are also released with the help of blood circulation.
9. How many chambers does the human heart have? Give names.
Ans: 

  1.    Right Atrium
  2.    Left Atrium
  3.    Right ventricle
  4.  Left Ventricle

10. Describe the structure of the human heart.

Ans: The heart of a man is a muscular organ. It pumps the blood. It is located in the chest. The size of our heart is about the size of our fist.
It has four chambers.
1. Right Atrium 2. Left Atrium 3. Right ventricle 4. Left Ventricle

 The right atrium receives deoxygenated blood from the body and passes it to the right ventricle. From the right ventricle, blood is carried by the pulmonary arteries to the lungs for oxygenation. The left atrium receives oxygenated blood from the lungs by the pulmonary vein and passes it to the left ventricle pumping the blood to all parts of the body. 

How does the human heart work? Watch this video completely. 

11. How does our heart work?

Ans:  Human heart acts as a double pump. Blood from the lungs and other body parts enters the atria. The two atria contract at the same time and push the blood to the ventricles. It is one pump. It is one pump. Now both ventricles contract at the same time and pump the blood to the lungs and other parts of the body. It is the second pump. 
12. How many times do our heartbeats in one minute? 
Ans: Our heart beats about 70 times a minute. 
13. How does exercise affect your heartbeat rate?
Ans: We need more food and oxygen while taking exercise so, our heart pumps the blood fast while taking exercise. 

14. Compare the structures and functions of blood vessels.
Ans: These are the blood vessels that are responsible for the transportation of blood throughout the body.
These are mainly divided into three kinds.

  1. Arteries
  2. Capillaries
  3. Veins

Arteries:

Arteries carry oxygenated blood from the heart to all parts of the body. These are the pulmonary arteries that carry deoxygenated blood to the lungs. They have thick muscular walls. Arteries enter tissues and are divided into many smaller tubes called capillaries.

Capillaries:

These are microscopic blood vessels. Only one red blood cell can flow into them at one time. Capillaries are responsible for the exchange of food, oxygen, waste materials, and carbon dioxide between the blood and cells.

Veins:

Capillaries again join together and form larger blood vessels called veins. They carry deoxygenated blood from the body to the heart.
These are the Pulmonary veins that carry oxygenated blood from the lungs to the heart.

15. How can we keep our heart and blood vessels healthy and fit? 
Ans: We can keep our heart and blood vessels healthy and fit by acting upon the following tips:
  1. Take foods high in fiber and low in fat. 
  2. Take exercise regularly. 
  3. Don’t smoke. smoking can increase your blood pressure. 
16. What is diabetes? 
Ans: Diabetes is a disease in which a person has high blood sugar. The reason is that his body does not produce insulin. Insulin helps to decrease blood sugar. 
17. What is insulin? 
Ans: Insulin is the chemical that is produced in our pancreas. Insulin helps to decrease blood sugar. Without insulin, a person develops diabetes. 
18. How can we control our blood sugar?
Ans: We can control our blood sugar level by taking medicines, eating a proper diet, and taking exercise. 

19. What is asthma: 

Ans: Asthma is an allergy that causes the airways of the lungs to swell and narrow. 

20. What are the symptoms of asthma?
Ans: The symptoms of an asthma attack may be cough, shortness of breath, wheezing, extreme difficulty in breathing, chest pain, sweating, and increased pulse.
21. What are the precautions to avoid asthma?  
Ans: We can be normal and active even with asthma by acting upon the following tips. 

  1. Try to avoid allergens of asthma.
  2. Use plenty of water, it gives relief.  
  3.  Use an inhaler or medicine on the advice of a doctor. 
22. Describe that structure of a plant’s root permits the movement of materials.
Ans: The structure of the root of the plant permits the movement of materials. The root is formed by the radical of the embryo of the seed. It is divided into branches and root hairs. Root hairs absorb water and minerals from the soil and pass them to the stem.
The xylem tissues of the root are responsible for the movement of water from the soil to the stem and then to the leaves.
The phloem tissues transport food from leaves to all parts of the plant like stem, roots, and flower, etc.
23. Describe the structure of the plant’s leaf.

Ans: Structure of a Leaf

Leaves are the food factories of plants. The upper layer of a leaf has a waxy layer cuticle to reduce water loss.
The lower layer of a leaf has stomata. The exchange of gases and transpiration takes place through stomata.
The midrib and veins of a leaf have xylem and phloem tissues. These tissues (xylem and phloem) or blood vessels transport water and food throughout the leaf.
24. What is transpiration?
Ans: The loss of water by evaporation from plants is called transpiration.
25. What is diffusion?
Ans: Diffusion is the movement of a substance from where it is in large amounts to where it is in small amounts.
26. How do plants transport materials?
Ans: Plants transport water and minerals from roots to leaves through xylem vessels.
Phloem transports prepared food from leaves to all other parts of the plants.

27. What is translocation?

Ans: The movement of prepared food from leaves to those parts of the plant’s bodies where it is needed is called translocation.

28. Describe the structure and function of the plant roots. 
Ans: Roots have branches that play an important role in the absorption of water. The root hair on the roots absorbs water and minerals from the soil. Roots have xylem tissues to move water and minerals from the soil up through the stems, to the leaves. phloem tissues in roots help to transport food. 

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