Tag: biology

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Multiple choice biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

In cardiac circulation, "dupp" sound is heard, when

  1. Mitral valves closes

  2. Mitral valves opens

  3. Semilunar valves closes

  4. Tricuspid valve closes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

During each cardiac cycle two prominent sounds are produced, which can be easily heard through a stethoscope. The first heart sound ('lubb') is associated with the closure of the tricuspid and bicuspid valves, whereas the second heart sound ('dubb'/'dupp') is associated with the closure of the semilunar valves. 

Multiple choice biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

Pressure exerted by blood against walls of an artery during ventricular expansion is 

  1. Systolic Pressure

  2. Ventricular Pressure

  3. Both A and B

  4. Cardiac output
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pressure exerted on the arterial wall during left ventricular contraction pushing blood into the aorta. This is called ventricular pressure or ventricular systole. During ventricular systole closing of atrioventricular valves produces the first heart sound lubb. Thus, the correct option is B.

Multiple choice biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

Normal rate of heart beat in a human being is________.

  1. 32/minute

  2. 42/minute

  3. 52/minutes

  4. 72/minute
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The cardiac cycle refers to a complete heartbeat from its generation to the beginning of the next beat. The frequency of the cardiac cycle or the heart rate is expressed as heart beats per minute. Systole is the contraction of the cardiac muscles in response to an electrochemical stimulus to the heart's cells. It is a force that drives blood out of the heart. Diastole is the period when the heart refills with blood after systole (contraction). The normal rate of heart beat is 72/minute.
So, the correct answer is option D.
Multiple choice biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

The heart is an organ which beats

  1. Twenty hours in twenty four hours

  2. Ten hours in twenty four hours

  3. Continuously

  4. Eight hours in twenty four hours
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The heart beat continuously and pumps the blood by contraction and relaxation of cardiac muscles.
Cardiac output is defined as the amount of blood pumped out by the ventricles in a minute.The volume of blood pumped by each ventricle in 1 minute is termed as the cardiac output. 
So, the correct answer is option C.

Multiple choice biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

Normal heart rate of a healthy individual is 

  1. 20-40 beats/min

  2. 60-100 beats/min

  3. 200-600 beats/min

  4. 2-10 beats/min
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The cardiac cycle refers to a complete heartbeat from its generation to the beginning of the next beat. The frequency of the cardiac cycle or the heart rate is expressed as heart beats per minute. Normal adult human heart rate ranges from 60-100 bpm. So, the correct answer is option B.

Multiple choice biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

Heart beat is  initiated by

  1. Sinu-auricular node

  2. Atria-ventricular node

  3. Sodium ion

  4. Purkinje's fibres
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sino-atrial node (SAN) is a mass of nodal tissue found in the upper part of right auricle. It generates the nerve impulses which is responsible for starting the contraction of the heart. It controls the rhythm of the heart contraction. Hence, it is called as the natural pacemaker of the heart.

Multiple choice biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

Pulse rate can be defined as

  1. The rate at which the blood is pumped

  2. The rate at which the blood is filtered

  3. The rate at which the blood is oxygenated

  4. The rate at which the blood is deoxygenated
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This sequential event in the heart which is cyclically repeated is called the cardiac cycle. Each cardiac cycle consists of systole and diastole of both the atria and ventricles. Each cardiac cycle represents one heartbeat. The normal heart rate is about 72 beats per minute. The heart rate is same as pulse rate because the pumping action of the heart causes an increase in blood pressure in arteries that leads to noticeable pulse. Hence pulse rate can be defined as the rate at which the blood is pumped.

So, the correct answer is 'The rate at which the blood is pumped'.

Multiple choice biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

In which animal there is no blood for transport of nutrients?

  1. Fish

  2. Hydra

  3. Sponges

  4. Both B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

All vertebrates possess a muscular chambered heart. Fishes have a 2-chambered heart with an atrium and a ventricle. In fishes, the blood transports nutrients when the heart pumps blood throughout the body. Animals like hydra and sponges do not possess any circulatory system. The water in which they live brings food and nutrients as it enters their body. The water carries waste materials and carbon dioxide as it moves out. Hence In animals like hydra and sponges, there is no blood for transport of nutrients.

So, the correct answer is 'Both B and C'.

Multiple choice biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

The normal heart rate is

  1. 62 beats per minute

  2. 72 beats per minute

  3. 54 beats per minute

  4. 52 beats per minute
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • This sequential event in the heart that is cyclically repeated is called the cardiac cycle.
  • Each cardiac cycle consists of systole and diastole of both the atria and ventricles. 
  • Each cardiac cycle represents one heartbeat. The number of heartbeats per minute in resting person is called a normal heart rate. 
  • The normal heart rate is about 72 beats per minute.

So, the correct answer is '72 beats per minute'.