Tag: biology

Questions Related to biology

A patient suffering from splenomegaly undergoes splenectomy. Which of the following processes will be affected?

biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

  1. RBC production will be stopped.

  2. Removal of old RBC will be impaired.

  3. Decreases in antibody production.

  4. Generation of B cells will be stopped.

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Correct Option: B
Explanation:

Splenomegaly is a condition of enlargement of the spleen. This is a condition of overload that suggests overload. It is called so because as the spleen grows its main function is to destroy or remove the old RBC and abnormal RBC and also prevents the infections by producing white blood cells. 
So in the condition of splenomegaly the removal of RBC will be impaired.

Acetyl choline causes

biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

  1. Bradycardia

  2. Tachycardia

  3. Both A and B

  4. None of the above

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Correct Option: A
Explanation:

As the body fluids and tissues are good conductors of electricity, the electrical activity within the heart can be detected by attaching electrodes to the surface of the body. The pattern of electrical activity may be displayed on an oscilloscope screen or traced on paper. The apparatus used is an electrocardiograph and the tracing is an electrocardiogram (ECG). The normal ECG tracing shows five waves which, by convention, have been named P, Q, R, S and T. The standard ECG originates from the SA node and is known as sinus rhythm. The rate of sinus rhythm is 60 to 100 beats per minute. A faster heart rate is called tachycardia and a slower heart rate, bradycardia. Acetylcholine is a neurotransmitter of parasympathetic system of nerves and slows down heart rate.

The disease erythroblastosis fetalis in human embryo is caused due to:

biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

  1. Disadjustment of blood groups

  2. Disadjustment of Rh factor

  3. Both A and B

  4. None of the above

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Correct Option: B
Explanation:

Erythroblastosis fetalis is hemolytic anemia in the fetus caused by transplacental transmission of maternal antibodies to the fetal RBCs. The disorder usually results from incompatibility between the maternal and fetal blood groups, often Rh antigens. Erythroblastosis fetalis classically results from Rh incompatibility, which may develop when a woman with Rh-negative blood is impregnated by a man with Rh-positive blood and conceives a fetus with Rh-positive blood.
Thus, the correct answer is option (B), 'Disadjustment of Rh factor'.

A root hair cell under ordinary conditions have a water potential in the range of?

biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

  1. $-1$ to $-4$ atm.

  2. $-1$ to $+4$ atm.

  3. $1$ to $2$ atm.

  4. $-1$ to $2$ atm.

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Correct Option: A

Which of the following is an important feature of roots which help them to absorb water and minerals from the soil?

biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

  1. Roots provide very less surface area

  2. Cells of root contain cell sap

  3. Root hairs have thick walls

  4. All of the above

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Correct Option: B
Explanation:

Larger surface area and thinner walls of root hair are required to absorb water efficiently. 

Cells of the root contain sap which has an accumulation of ions which significantly reduces the water potential. Hence water enters the cells from the soil passively. 
So the correct answer is ' Cells of root contain cell sap'. 

The cells of the roots contain cell sap at a .................. concentration than that of surrounding soil water.

biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

  1. Higher

  2. Lower

  3. Equal

  4. All of the following

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Correct Option: A
Explanation:

The cells of the roots contain cell sap (solution) at a higher concentration than that of surrounding soil water. As a result, the water is absorbed by the root hairs. This is because the water always travels from a region of high water potential to the region of lower water potential. Here, the soil possesses a higher water potential as compared to the root hair.

Mineral absorption occurs.

biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

  1. If soil solution is hypotonic

  2. If soil solution is hypertonic

  3. Independent of water potential

  4. Independent of water absorption

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Correct Option: D

Rupture and fractionation of water column present in tracheary elements does not occur during ascent of sap due to

biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

  1. Transpiration pull

  2. Weak gravitational pull

  3. Cohesion and adhesion

  4. Lignified thick walls

Show answer
Correct Option: C
Explanation:

Transpiratioal or gravitational pull exert strain so they are factors that can cause rupture of the column. 

Lignified walls are only present for structural support.
Cohesion ( attraction of water molecules towards each other) and adhesion (attraction of water molecules and the walls of the tube ) is the reason why  the column doesn't break as these attractive forces overcome the strain developed by Transpiration pull. 
So the correct answer is 'Cohesion and adhesion'.

In root hair, water enters due to.

biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

  1. Diffusion

  2. WP

  3. T.P.

  4. O.P.

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Correct Option: A

If a cell A with OP $10$ bars and TP $4$ bars is connected to cells B, A and D having OP and TP respectively $4$ and $4$, $10$ and $5$ and $7$ and $3$ bars, the flow of water will be.

biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

  1. C to A, B and D

  2. B to A, C and D

  3. D to A, B and C

  4. A to B, C and D

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Correct Option: A