Class 7 Basic Science Chapter 7 Question Answer Notes Human Body A Wonder Circulation, Excretion and Nervous Co Ordination

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Human Body A Wonder Circulation, Excretion and Nervous Co Ordination Class 7 Questions and Answers Notes

Class 7 Basic Science Chapter 7 Human Body A Wonder Circulation, Excretion and Nervous Co Ordination Question Answer Pdf

Basic Science Class 7 Chapter 7 Question Answer Kerala Syllabus

Let Us Assess

Question 1.
Which among the following organs does not perform the function of excretion?
a) Kidney
b) Liver
c) Heart
d) Lungs
Answer:
c) Heart

Question 2.
Which of the following statements is correct?
a) Pulse rate increases while running
b) All Individuals have the same pulse rate
c) Pulse rate can be checked at the wrist only
d) Pulse rate and heart rate are different
Answer:
a) Pulse rate increases while running

Question 3.
What should be done to prevent urinary infections?
Answer:
To prevent urinary infections:

• Drink plenty of water, especially 8-12 glasses a day.
• Urinate frequently
• Practice good hygiene
• Eat vitamin C-rich foods

Question 4.
What are the physical discomforts that may occur during menstruation?
Answer:
Some people may experience severe abdominal pain, vomiting, back pain and leg cramps before and during menstruation. Some may also develop excessive anger and anxiety during this period.

Question 5.
The most important organ in the human body is the brain. Substantiate.
Answer:
The brain is often considered the most important organ in the human body due to its complex and critical functions. It controls and coordinates all bodily activities, including:

• To control movements of various muscles of the body
• Coordinate all activities of the body and give instructions to the cells.
• The brain is the centre of vision, hearing, memory, intelligence, imagination, and emotions.

If the brain were to cease functioning, all other bodily functions would eventually shut down. Therefore, it is widely considered the most vital organ for human life.

Class 7 Basic Science Chapter 7 Extended Activities Answers

Question 1.
Prepare and display a chart showing measures to be taken to maintain a healthy heart.
Answer:
(Hint: Given below is a model chart showing measures to be taken to maintain a healthy heart for your reference).

Question 2.
Prepare posters as part of the anti-drug awareness campaign and display them in your school.
Answer:

Question 3.
Prepare an interview schedule to conduct an interview with the doctor on the topic ‘Adolescent Health and Eating Habits’.
Answer:
(Hint: Given below a model of an interview schedule based on the given topic for your reference)
Interview Schedule for the topic: Adolescent Health and Eating Habits
Interviewer: [Your Name]
Interviewee: [Doctor’s Name]
Date: [Date] Time: [Time]

Introduction

• Brief introduction: Introduce yourself and your role.
• Purpose of the interview: Explain the purpose of the interview and how the information will be used.
• Consent: Obtain the doctor’s consent to conduct the interview and record it.

Background

• Doctor’s qualifications and experience: Inquire about the doctor’s qualifications and experience in adolescent health and nutrition.
• Areas of expertise: Ask about the doctor’s specific areas of expertise within adolescent health.

Adolescent Health and Eating Habits

• Common health issues
• Impact of eating habits
• Nutritional needs
• Common dietary mistakes
• Eating disorders
• Role of parents and caregivers
• School-based programs
• Cultural factors

Advice and Recommendations

• Healthy eating tips: Ask for practical tips on promoting healthy eating habits among adolescents. *
• Addressing concerns: Discuss how to address concerns about adolescent eating habits.
• Resources: Inquire about relevant resources for adolescents and their families.

Conclusion

• Summary: Summarize the key points discussed during the interview.
• Thank you: Thank the doctor for their time and insights.

Class 7 Basic Science Chapter 7 Intext Question and Answers

Question 1.
Why are some drugs and glucose injected directly into the blood? Does the glucose injected into the blood reach all parts of the body? Discuss.
Answer:
Some drugs, like insulin and glucagon, are injected directly into the body to treat conditions that affect blood sugar levels. Glucose is an essential energy source for the body’s organs and systems. The pancreas secretes insulin to control how much glucose is used by the body. When glucose levels are too high or too low, it can lead to serious health problems like heart disease, kidney problems, and stroke.
Insulin moves glucose from your blood into cells all over your body. Once released in the bloodstream, glucose can be used immediately for energy or stored in our bodies, to be used later.

Question 2.
Observe the picture and write down the parts of the human circulatory system.

Answer:
• Heart
• Blood
• Blood vessels

Question 3.
Do you know the colour of our blood? Why is blood red in colour?
Answer:
The colour of our blood is red due to the presence of an iron-containing pigment called haemoglobin.

Question 4.
Observe the picture of some food items containing iron. Find out the other food items containing iron and record it in the science diary

Answer:

• Nuts and seeds
• Dried fruit
• Spinach
• Broccoli
• Iron-fortified bread and breakfast cereal.

Question 5.
Analyse the illustration and write the answers to the following questions in the science diary.

a) Which is the liquid part of blood?
b) Which are the blood cells?
c) What is the function of platelets?
d) In which blood cell is haemoglobin found?
e) Differentiate between RBC and WBC.
Answer:
a) Plasma
b) RBC (Red blood cells), WBC (White blood cells) and Platelets.
c) Platelets are disc-shaped cells in the blood that help stop bleeding (blood clotting) and heal wounds.
d) Haemoglobin is found in red blood cells (RBC).

Question 6.
Do all organisms have a heart? Do the hearts of other organisms also have four chambers?
Answer:
No, not all organisms have a heart, and the number of chambers in an organism’s heart varies depending on the type of animal.
Earthworms- 5 pairs of lateral hearts
Cockroach- 13 chambers
Fishes – 2 chambers
Frog – 3 chambers
Birds and Mammals – 4 chambers

Question 7.
Observe the picture. Which are the body parts that are examined to feel the pulse?
Answer:

• The wrist
• Both sides of the forehead
• Neck
• Behind the knee
• Inside the elbow
• The foot

Question 8.
Observe the picture of a doctor examining a child. What instrument does the doctor use? What is its use? Write it in the science diary.
Answer:
Stethoscope. It is an instrument used to check the heartbeat.

Question 9.
Compare the heart rate and pulse rate of your friends. What are your findings? Record them in your science diary.
Answer:

Name of the child	heart rate (beats/minute)	Pulse rate(beats/minute)
Akhil	70	70
Sarayu	76	76
Gouri	69	69
Tony	72	72
Anvar	73	73

Question 10.
Will there be any change in the heart and pulse rates during strenuous activities? Find out the change in the heart and pulse rates of your friends who have been running around for some time. Write them down in your science diary.
Answer:
(Persons and values are just for your reference)

Name of the child	Heart rate (beats/minute) after running (exercise)	Pulse rate (beats/minute) after running (exercise)
Akhil	96	96
Sarayu	115	115
Gouri	110	110
Tony	99	99
Anvar	96	96

Question 11.
Check the heart rate and pulse rate of the elders at your home, record them in the science diary, and present them in the class.
Answer:
(Hint: Persons and values are just for your reference)

Question 12.
What is to be done if there is a decrease in the volume of blood due to accidents or illness?
Answer:
Once you are in an ambulance or at the hospital, first your provider will give you fluids (like saline)* and then blood through an IV, a bag of liquid attached to a needle that goes directly into a vein. Most people who lose more than 30% of their blood volume will also need a blood transfusion.

Question 13.
Prepare slogans related to blood donation and display in the class.
Answer:

Question 14.
Which gas is produced as a result of respiration? Which organ eliminates it?
Answer:
CO₂ (Carbon dioxide). Lungs eliminate this gas as a result of respiration.

Question 15.
What are the other waste materials produced in our body?
Answer:
Other than carbon dioxide, water, salts, urea, and uric acid are the other waste materials that are produced in the body.

Question 16.
Discuss the given questions with the help of the following notes and picture. Record your findings in the science diary.

Kidney and Filtration
Kidneys are bean-shaped and are located in the abdominal cavity on either side of the vertebral column. The renal artery carries blood to the kidneys. This blood contain urea, glucose, salts, oxygen and other components. But the blood returning through the renal vein after filtration contains comparatively less amount of urea, glucose, salts, oxygen and other components. The waste products in the blood thus filtered by the kidneys are eliminated through urine. Kidneys play an important role in maintaining the proper concentration of water and salts in the body. The average daily output of urine from a healthy person is 1.5 litres.

a) Which blood vessel carries blood to the kidneys?
b) Which blood vessel carries blood back from the kidneys?
c) How does the blood in the renal artery differ from that in the renal vein?
d) Which tube carries urine from the kidneys?
e) In which part of the excretory system is urine collected?
Answer:
a) Renal artery
b) Renal vein
c) The renal artery carries blood to the kidneys and it contains urea, glucose, salts, oxygen, and
other components. However, the blood returns through the renal vein after filtration (that is, the blood in the renal vein), which contains comparatively less urea, glucose, salts, oxygen, and other components.
d) Ureters
e) Urinary bladder

Question 17.
What are the health problems that will occur if you don’t drink enough water and urinate at regular intervals?
Answer:
Proper functioning of the kidneys requires an adequate intake of water. If we do not urinate for a long time, pathogens will multiply in the urethra and bladder, leading to urinary infections. Burning sensation while urination, and abdominal pain are also other symptoms of such urinary infections.

Question 18.
What are the measures we should take care of to protect the health of our kidneys? Discuss in the class and record them in the science diary.
Answer:

• Avoid smoking and drinking liquor
• Reduce excess use of salt
• Reduce the use of unnecessary medicines
• Drink at least 12 glasses of water daily
• Avoid overuse of artificial drinks
• Exercise regularly

Question 19.
What are the means to save someone suffering from kidney failure?
Answer:
• Dialysis
• Kidney transplantation

Question 20.
Sweat is produced in our body during the summer and rainy seasons. How is it eliminated from the body? What materials are expelled from the body through sweat?
Answer:
Sweat from the sweat glands is eliminated through minute pores in the skin. Materials expelled from the body through sweat are:

• Water
• Salt

Question 21.
Analyse the given note and find out the functions of the skin. Write them in your science diary.
Sweat
Sweat is produced by sweat glands in the skin. Excess water and salt in the body are eliminated through sweat. The heat to evaporate sweat is taken from our body. Sweating thus helps in our temperature regulation. Protecting the body by covering it and sensing touch are also the functions of skin.
Answer:
The skin is the body’s largest organ, made of water, protein, fats and minerals. Sweat is produced by sweat glands in the skin. The skin protects our body by covering it and by sensing touch.

Question 22.
Read the notes on lungs and liver. Discuss the points given below with your friends and record them in the science diary.

a) Which organ eliminates carbon dioxide produced in the cells?
b) Name the largest gland in the human body.
c) Which chemical substance is produced by the liver?
d) What are the functions of the liver?
Answer:
a) Lungs
b) Liver
c) Bile
d) Bile synthesised by the liver helps in the digestion of fat. The liver converts the toxic ammonia into less toxic urea.

Question 23.
Imagine that a pen fell down from your hand. Which are the organs that function when we pick it up? Write them down.
Answer:
The key parts of the nervous system involved here are the brain, the spinal cord, and the hand and finger muscles that respond to the impulse by contracting to allow the grabbing and lifting of the object.

Question 24.
How is the coordination of various activities possible in our body?
Answer:
By the action of the nervous system in our body.

Question 25.
Don’t you close your eyes instinctively if an insect flies towards your eyes? How about lighting a torch into your eyes? How will we respond to such situations?
Answer:
When an insect flies towards our eyes or lights a torch into our eyes, we suddenly blink our eyes or resist that condition with our hands. This is a kind of reflex action that happens by the coordinated activity of our nervous system.

Question 26.
Read the note given below and find answers to the questions. Write them in the science diary and present them in the class.
a) What are the main functions of the brain?
b) Name the bony covering that protects the brain.
c) What are the main parts of the nervous system?
Answer:
a) The main functions of the brain include:

• To control movements of various muscles of the body
• Coordinate all activities of the body and give instructions to the cells.
• The brain is the centre of vision, hearing, memory, intelligence, imagination and emotions.

b) Skull

c) The main parts of the nervous system are:

• The brain
• Spinal cord and
• Nerves

Question 27.
What methods do girls adopt to manage menstrual blood?
Answer:
Here are some common methods that girls adopt to manage menstrual blood:

• Sanitary pads
• Menstrual cups
• Menstrual discs
• Period underwear

Question 28.
Discuss the advantages and disadvantages of using sanitary napkins during menstrual periods.
Answer:

Advantages	Disadvantages
Sanitary pads absorb and retain menstrual fluid.	Difficulty in disposing
Available in different sizes	Wearing a pad for too long can cause mutation, redness, and rashes.
Sanitary pads are designed to be leakproof.	Sanitary pads can be expensive over time

Question 29.
What are the benefits of using a menstrual cup? Discuss and record them in the science diary.
Answer:

• A menstrual cup is often cheaper than using tampons and pads long-term because it is reusable
• Reduced irritation and vaginal dryness.
• Less mess and odour.
• Fewer leaks
• Longer wear time

Question 30.
What kind of food should we take during adolescence? Discuss based on the indicators given below.

• Body growth during adolescence is rapid.
• A girl loses about 0.6 litres of blood during menstruation.

Answer:
Adolescence is a period of rapid growth and development characterized by significant physical and hormonal changes. Proper nutrition is essential to support these changes and ensure optimal health. Food Recommendations are:
Carbohydrates: Complex carbohydrates like whole grains, fruits, and vegetables provide sustained energy.
Protein: Protein is essential for building and repairing tissues. Lean sources like poultry, fish, beans, and lentils are recommended.
Healthy Fats: Healthy fats found in nuts, seeds, and avocados are important for brain health and hormone production.

Question 31.
Considering the blood loss and rapid body growth, how should adolescents adjust their food habits?
Answer:

• Cut down on sweets, cakes, biscuits, and fizzy drinks.
• Eat fewer fatty foods such as chips, burgers, fried food, and processed foods such as instant noodles.
• Eat regular balanced meals.
• Base meals on starchy foods, choosing wholegrain varieties whenever possible.
• Eat more fruit and vegetables.

Human Body A Wonder Circulation, Excretion and Nervous Co Ordination Class 7 Notes Extra Questions and Answers

Question 1.
The heart is the centre of the blood circulatory system. It pumps blood to all parts of the body. What are the peculiarities of the human heart?
Answer:

• The Heart is the centre of the circulatory system.
• It pumps blood to all parts of the body.
• It is located in the thoracic cavity between the lungs.
• The heart is about the size of a clenched fist
• It is covered by a double-layered membrane called pericardium
• It is protected by ribs
• The human heart has four chambers.

Question 2.
All organisms have a heart. Some names of organisms are given. Write the number of chambers of their heart.
Bird, Crocodile, Fish, Cockroach, Earthworm.
Answer:
Bird – Four-chambered heart
Crocodile – Four-chambered heart
Fish – Two-chambered heart
Cockroach – Thirteen chambered tubular heart.
Earthworm – Five pairs of lateral heart.

Question 3.
What are injurious to cardiac health?
Answer:

• Regular use of excessive fatty food items.
• Excessive use of salt.
• Smoking
• Lack of exercise
• Continuous intake of medicines.

Question 4.
Blood is a fluid connective tissue, not an organ of the circulatory system.
a) Can you explain why certain medicines, glucose, etc., are injected into the blood?
b) Why is human blood red in colour?
c) What is the use of a Stethoscope?
Answer:
a) Through blood, the medicine and glucose are easily transported to different parts of the body.
Hence, we get a sudden effect.
b) Due to the presence of haemoglobin.
c) It is used to measure the heartbeat.

Question 5.
A) Fill the table below based on the blood circulatory system.

B. Name the pigment which gives red colour to blood.
C. For maintaining health of the heart, we have to follow some health habits. Write any two of them.
Answer:
A. i) White blood cells, ii) Plasma, iii) Blood vessels (artery, vein, Capillary) iv) Blood
B. Haemoglobin
C. Habits for a healthy heart:
• Avoid the excessive use of fatty food items.
• Avoid tension and smoking.

Question 6.
Excretion is the process of elimination of urea, excess waste, salts, etc., that are produced in the body as a result of life processes.
a) What is the function of the kidney in our body?
b) What all are expelled from the body through sweat?
Answer:
a) The function of the kidney is to filter excess urea, water and salts in the blood, and are expelled from the body in the form of urine.
b) Salt and water

Question 7.
Observe the pictures.

A. Identify and name the organs mentioned in the pictures.
B. One of the organs does not belong to this group. Which organ? Why?
C. What difference is there in the amount of urea in the blood vessel that reaches the kidney and leaves the kidney?
Answer:
A. 1 – Kidney,
2 -Skin,
3 – Lungs
B. Skin. It is an external organ that covers the body.
C. The blood vessel that reaches the kidney has urea in greater quantities, and the blood vessel that leaves the kidney has urea in lesser quantities.

Question 8.
A. What are the main waste products removed by the excretory system?
B. How do the kidneys help to regulate the body’s water balance?
Answer:
A. Urea, uric acid, and excess water.
B. The kidneys adjust the amount of water excreted in urine to maintain the body’s water balance.

Question 9.
What are neurons? What is its role in nervous coordination in the human body?
Answer:
Neurons (nerve cells) are the fundamental units of the brain and nervous system. They are responsible for sending and receiving signals throughout the body, allowing us to move, feel sense, and perform other functions

Question 10.
A) What is adolescence?
B) What are some of the physical changes that occur during adolescence?
Answer:
A) Adolescence is the period of life between childhood and adulthood, typically from ages 10 to 19.
B) Puberty, changes in body shape, and the development of secondary sex characteristics.

Question 11.
a) What is the importance of nutrition and exercise during adolescence?
b) What are some of the benefits of physical activity for adolescents?
Answer:
a) Good nutrition and regular exercise are essential for healthy growth and development.
b) Improved physical and mental health, reduced risk of chronic diseases, and increased self-esteem.

Question 12.
If your school health club conducting a seminar on the topic ‘Adolescence and sexual exploitation’, mention the important points to be discussed in that session.
Ans:
• Define adolescence and sexual exploitation and explore the physical, emotional, and social changes that occur during adolescence.
• Discuss the impact of peer pressure, social media, and cultural influences on adolescent behaviour.
Highlight the importance of healthy relationships and boundaries.
Define different forms of sexual exploitation that can affect adolescents (e.g., child sexual abuse, dating violence, online grooming).
Discuss common signs and symptoms of sexual exploitation in adolescents.
Discuss the role of schools and communities in promoting healthy relationships and preventing sexual exploitation.
Online Safety and awareness and empowering adolescents.

Human Body A Wonder Circulation, Excretion and Nervous Co Ordination Class 7 Notes

• The major parts of the human circulatory system include the heart, blood and blood vessels.
• RBC, WBC, Platelets and plasma are the major components of blood, and they flow through different blood vessels to all parts of the body: Arteries, veins and capillaries.
• The Heart is the centre of the circulatory system, and it pumps blood to all parts of the body. Heart transplantation is performed on people with severe heart disease.
• Excretion is the process of elimination of urea, excess waste, salts, etc., that are produced in the body as a result of life processes.
• Kidneys, the main organ of the human excretory system, are bean-shaped and are located in the abdominal cavity on either side of the vertebral column.
• Kidney transplantation is the process of transplanting one kidney from a healthy donor to a person whose both kidneys are impaired.
• The main excretory organs in human beings other than kidneys are the lungs, liver, and skin. They all excrete waste, and together, they make up the excretory system.
• The human nervous system is composed of the brain, spinal cord, and nerves.
• Adolescence is a crucial stage of growth and development, characterized by rapid physical and mental changes. Proper nutrition plays a pivotal role in supporting these changes and ensuring overall health.
• Children have the right to get protection from all kinds of exploitation.