Tag: biology

Questions Related to biology

Read the following statements and choose the correct option.
Statement 1: Atrial receives blood from all parts of the body which subsequently flows to ventricles.
Statement 2: Action potential generated at sino-atrial node passes from atria to ventricles.

biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

  1. Action mentioned in Statement 1 is dependent on action mentioned in Statement 2.

  2. Action mentioned in Statement 2 is dependent on action mentioned in Statement 1.

  3. Actions mentioned in Statements 1 and 2 are independent of each other.

  4. Actions mentioned in Statements 1 and 2 are synchronous.

Show answer
Correct Option: D
Explanation:

Atria receive blood from all parts of the body which subsequently flows to the ventricles. Action potential generated at sinoatrial node passes from the atria to the ventricles. Both these events take place at the same time.

Thus, the correct answer is 'Actions mentioned in Statements 1 and 2 are synchronous.'

The atrio-ventricular node is situated

biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

  1. Near the bicuspid valve

  2. In between the atrium

  3. At the base of inter-auricular septum

  4. In the interventricular septum

Show answer
Correct Option: C
Explanation:

The heart beat originates at SA node and passes to the AV node which finally conducts it to the bundle of His. The AV node is placed between the atria and the ventricles of the heart, specifically in the posteroinferior region of the interatrial septum near the opening of the coronary sinus, which conducts the normal electrical impulse from the atria to the ventricles.

So, the correct answer is option C.

In which the following has the ability to generate action potentials without any external stimuli? 

biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

  1. Sino-atrial node(SAN)

  2. Atrio-ventricular node (AVN)

  3. Purkinje fibers

  4. All of the above

Show answer
Correct Option: A
Explanation:

Sino-atrial node(SAN)  is known as a pacemaker and has the ability to generate action potentials without any external stimuli. 

When the right ventricle of heart of man contracts then blood is pumped into

biology transport in mammals cardiac cycle heart, blood vessels and cardiac cycle human heart

  1. Superior vena cava

  2. Dorsal aorta

  3. Pulmonary artery

  4. Pulmonary vein

Show answer
Correct Option: C
Explanation:

The pulmonary artery is the vessel transporting de-oxygenated blood from the right ventricle to the lungs. Deoxygenated blood from the systemic circulation enters the right atrium from the superior and inferior venae cavae and passes to the right ventricle. From here it is pumped into the pulmonary circulation through the pulmonary artery, to the lungs where it receives oxygen and gives off carbon dioxide. 

So, the correct answer is option C.

Choose correct alternative in the following statements:
The only artery which carries deoxygenated blood is called

biology transport in mammals cardiac cycle heart, blood vessels and cardiac cycle human heart

  1. Hepatic artery

  2. Pulmonary artery

  3. Aorta

  4. Renal artery

Show answer
Correct Option: B
Explanation:

  • The only artery which carries deoxygenated blood is called the pulmonary artery. It carries deoxygenated blood from the right ventricle into the lungs for oxygenation. 
  • Hepatic artery is a short blood vessel that supplies oxygenated blood to the liver.
  • Aorta is the largest artery in the body. It carries oxygenated blood from left ventricle to the other parts of the body.
  • Renal artery carries oxygenated blood to kidneys.
Hence, the correct answer is 'Pulmonary artery'.

What happens when the pacemaker becomes non-functional?

biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

  1. Only auricles contract rhythmically

  2. Only ventricles contract rhythmically

  3. Cardiac muscles do not undergo coordinated rhythmic movements

  4. Cardiac muscles contract in coordinated manner rhythmically

  5. Auricles and ventricles contract rhythmically.

Show answer
Correct Option: C
Explanation:

The natural (SA node) or artificial pacemaker has a function to send electrical impulses from atrium for contraction and pumping action into the ventricles. The impulses get transferred in the following route :

SA node(pacemaker) $\rightarrow$ Interatrial cardiac fibre $\rightarrow$ AV node(pacesetter) $\rightarrow$ Bundle of his $\rightarrow$ Bundle branch $\rightarrow$Purkinje fibres.
Thus, the rhythmic contraction of the heart is made by SA node.
So, if the pacemaker becomes non-functional then, cardiac muscles do not undergo coordinated rhythmic movement.

Choose the correct answer from the alternatives given.
Which of the following blood vessels carries oxygen poor blood from the heart to lungs?

biology transport in mammals cardiac cycle heart, blood vessels and cardiac cycle human heart

  1. Pulmonary vein

  2. Pulmonary artery

  3. Carotid artery

  4. Aorta

Show answer
Correct Option: B
Explanation:

Pulmonary veins are responsible for carrying oxygenated blood from the lungs back to the left atrium of the heart. The pulmonary artery is responsible for transporting oxygen-depleted blood away from the heart and back toward the lungs. Carotid artery is present in the neck region and supply blood to the brain, neck, and face. The aorta is the artery that carries blood away from the heart to the rest of the body. So, the correct option is 'Pulmonary artery'.

Choose the correct answer from the alternatives given.
Which of the following parts of the heart pumps blood to lungs?

biology transport in mammals cardiac cycle heart, blood vessels and cardiac cycle human heart

  1. Left atrium

  2. Right atrium

  3. Left ventricle

  4. Right ventricle

Show answer
Correct Option: B
Explanation:

Right atrium is just below the right atrium and receives deoxygenated blood from the right atrium and then pumps this deoxygenated blood to the lungs through the pulmonary artery.

So, the correct option is 'Right atrium'.

'Bundle of His' is a part of which one of the following organs in humans?

biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

  1. Brain

  2. Heart

  3. Kidney

  4. Pancrease

Show answer
Correct Option: B
Explanation:

Bundle of His is a part of heart, It is collection of heart muscles cells and specialized for electrical conduction .So option (B) Heart is correct answer.

Blood is not a tissue because it is a fluid

biology transport in mammals cardiac cycle heart, blood vessels and cardiac cycle human heart

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Blood is considered a connective tissue due to two basic reasons: (1) Embryologically, it has the same origin (mesodermal) as other connective tissues (2) Blood connects the body systems together and transports the required oxygen, nutrients, hormones and other signaling molecules, and removes the wastes. 
So, the correct answer is option B.