Heart

Q.

What are the components of the transport system in human beings? What are the functions of these components?

Q.

When are the sound "LUB" and "DUB" produced respectively during heart beat?

Q.

How many chambers are there in fish heart?

1. Two

2. Three

3. Four

4. One

Q.

Why do amphibians and reptiles have three-chambered hearts?

Q.

Describe the flow of blood through the heart of human beings.

Q.

Which chamber of heart has the thickest wall?

1. Right ventricle

2. Left ventricle

3. Right auricle

4. Left auricle

Q.

Question 58
What is the advantage of having the four-chambered heart?

Q.

Define heartbeat

Q.

The blood does not clot inside the body because of:

1. oxygenation of blood

2. movement of blood

3. presence of heparin in blood

4. absence of fibrinogen in blood

Q.

What is the pathway of blood through the heart?

Q.

How much of blood is water?

Q.

Why do people have a common belief that the heart is located on the left side of the chest?

Q.

If pulmonary arteries have deoxygenated blood then why they are called arteries?

Q. How does transportation in Human beings work?

Q.

Why do veins have valves but not arteries?

Q. The first heart sound (lub) is associated with:

1. Opening of pulmonary and tricuspid valves
2. Closure of bicuspid and aortic valves.
3. Closure of the tricuspid and bicuspid valves.
4. Opening of the tricuspid and bicuspid valves.

Q.

Name the four main forces responsible for the ascent of sap.

Q.

How do fishes cope up with two chambered heart where oxygenated and deoxygenated blood mix up unlike mammals which have four chambered heart for efficient flow of blood?

1. Fishes can store more energy than mammals.

2. Fishes do not have complex body structure like mammals.

3. Fishes have efficient gills.

4. Fishes do not require energy to maintain body’s temperature.

Q.

(a) How many types of blood vessels are there in the human body ? Name them.
(b) Why does the heart need valves ?

Q.

Question 19
Single circulation i.e., blood flows through the heart only once during one cycle of passage through the body, is exhibited by

(a) Labeo, Chameleon, Salamander
(b) Hippocampus, Exocoetus, Anabas
(c) Hyla, Rana, Draco
(d) Whale, Dolphin, Turtle

Q.

Draw a diagram of the front view of human heart and label any six parts (including at least two) that are concerned with arterial blood supply to the heart muscles.

Q.

Louder sound of heart beat occurs during closure of

1. Auriculo-Ventricular valves

2. mitral valve

3. Semilunar valves

4. Tricuspid valve

Q.

The advantage of separate chambers in heart of mammals and birds is ……...

1. helps to maintain constant body temperature.

2. helps in faster transport of oxygen to all parts of body

3. helps in energy production.

4. All of the above

Q.

How does blood circulate between lungs and heart in human beings ?

Q. Assertion: Mammals and birds are warm blooded organisms which maintain a uniform internal body temperature.
Reason: Mammals and birds have a four-chambered heart.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not a correct explanation of A.
3. A is true but R is false.
4. A and R are false.

Q.

Why is the heart divided into various chambers?

1. To ensure an efficient supply of oxygen in the body

2. To prevent oxygen-rich blood from mixing with carbon-dioxide rich blood.

3. Both a and b

4. Neither a nor b

Q.

Question 18
What prevents backflow of blood inside the heart during contraction?

(a) Valves in heart
(b) Thick muscular walls of ventricles
(c) Thin walls of atria
(d) All of the above

Q.

Give one word answer:

The valves present on the opening between auricle and ventricle

Q.

The oxygenated blood is found in the __________ side of the heart.

Q.

(a) What is meant by 'heart beat' ? What is the usual heart beat rate at rest ?
(b) What change occurs in heart beats if a person runs for a while Why ?