Tag: evs

Questions Related to evs

Which one is correct about the free living Rhizobium sp. and its enzyme?

evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

  1. Bacteria are aerobic and nitrogenase are active

  2. Bacterial are anaerobic and nitrogenase is active (operational)

  3. Bacteria aerobic and nitrogenase is inactive

  4. Bacteria are anaerobic and nitrogenase is inactive

Show answer
Correct Option: A
Explanation:

Rhizobium, is a rod shaped, aerobic, nitrogen fixing bacterium present in the root nodules of leguminous plants. It performs symbiotic nitrogen fixation in the root nodules of leguminous plants, in presence of an enzyme dinitrogenase.

So, the correct option is ‘bacteria are aerobic and nitrogenase are active’.

When the distance between the object and the plane mirror increases :

evs light, shadows and reflections characteristics of an image formed by a plane mirror formation of image in a plane mirror characteristics of the image formed by a plane mirror

  1. The image remains same

  2. The size of the image will become less than the size of the object.

  3. The distance between the image and the plane mirror increases

  4. The distance between the image and the plane mirror decreases

Show answer
Correct Option: C
Explanation:

When the distance between the object and the plane mirror increases because the distance between the image and the plane mirror increases.

Which of the following are the properties of plane mirror images?

evs light, shadows and reflections characteristics of an image formed by a plane mirror formation of image in a plane mirror characteristics of the image formed by a plane mirror

  1. The image is the same size as the object

  2. The image is virtual

  3. The image is inverted

  4. Image distance is equal to object distance

Show answer
Correct Option: A,B,D
Explanation:

In case of a plane mirror, image is virtual, erect, same size as the object and image distance is equal to object distance.

A point object is placed midway between two plane mirrors a distance apart. The plane mirrors form an infinite number of images due to multiple reflections. The distance between nth order images formed in the two mirrors is

evs light, shadows and reflections characteristics of an image formed by a plane mirror formation of image in a plane mirror characteristics of the image formed by a plane mirror

  1. $n a$

  2. $2 n a$

  3. $0.5 n a$

  4. ${ n }^{ 2 }a$

Show answer
Correct Option: C

In which of the following points pulmonary artery is different from pulmonary vein?

evs transportation in living organisms circulatory system and organs blood and blood vessels circulatory system blood pressure

  1. Its lumen is broad.

  2. Its wall is thick.

  3. It has valves.

  4. It does not possess endothelium

Show answer
Correct Option: B
Explanation:
The pulmonary artery carries deoxygenated blood from the heart to the lungs while the pulmonary vein carries oxygenated blood from the lungs to the heart. A pulmonary artery has a smaller lumen and thicker walls as compared to a pulmonary vein.
Thus, the correct answer is 'Its wall is thick.'

Given below are four statements (i-iv) regarding human blood circulatory system.
i. Arteries are thick-walled and have narrow lumen as compared to veins.
ii. Angina is acute chest pain when the blood circulation to the brain is reduced.
iii. Persons with blood group AB can donate blood to. any person with any blood group under ABO system.
iv. Calcium ions play a very important role in blood clotting.
Which two of the above statements are correct?

evs transportation in living organisms circulatory system and organs blood and blood vessels circulatory system blood pressure

  1. i and iv

  2. i and ii

  3. ii and iii

  4. iii and iv

Show answer
Correct Option: A
Explanation:

i. Arteries have thick, elastic walls and narrow lumen while veins have thinner, scarcely elastic walls and wide lumen.

ii. Angina Pectoris is a pain in the chest due to deprived oxygen the heart muscle experience constricting pain. This is not a fatal condition and the pain passes off quickly.
iii. Persons with blood group AB is a universal recipients. It has both the antigens A and B but no bodies.
iv.  During clot, Thromboplastin helps in the formation of an enzyme prothrombinase. This enzyme inactivates heparin and it also converts the inactive plasma protein prothrombin into its active form, thrombin. Both changes require calcium ions.
So, the correct answer is 'i and iv'.

Which of the following statements is incorrect?

evs transportation in living organisms circulatory system and organs blood and blood vessels circulatory system blood pressure

  1. Veins are typically larger in diameter than arteries.

  2. Because of their small size, blood flows more rapidly in capillaries than in other parts of circulatory system.

  3. Walls of arteries are elastic enabling them to stretch and shrink during changes in blood pressure.

  4. Veins contain more blood than any other part of circulatory system.

Show answer
Correct Option: B
Explanation:

A. Arteries have thick, elastic walls and narrow lumen while veins have thinner, scarcely elastic walls and wide lumen.

B. Arteries branch out into smaller and thinner blood vessels called arterioles. these divide into still smaller vessels to provide blood to all the cells. The thinnest blood vessels are called capillaries. The flow of blood is very slow in capillaries.
C. The walls of arteries are a muscular and elastic coat. It consists of unstriated muscle fibres with some yellow elastic fibres are arranged in a circular manner. It holds the blood vessel open. This layer determines the amount of supply of blood to an organ and it maintains the blood pressure.
D. Veins bring back blood from the tissues and organs to the heart. The blood in veins flows under less pressure than that in arteries. Therefore, veins can accommodate more blood.
So, the correct answer is 'Because of their small size, blood flows rapidly in capillaries than in other parts of circulatory system'.

State the following statement true or false:


Arteries have openings

evs transportation in living organisms circulatory system and organs blood and blood vessels circulatory system blood pressure

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Arteries do not have openings, while openings present in veins are called as valves. Blood after being pumped into arteries are under higher pressure than blood flowing in veins so to prevent backward flow of blood in veins valves are present.  Valves in veins also aid in the return of blood from the extremities to the heart.

So the correct answer is 'False'.

Splenic artery arises from?

evs transportation in living organisms circulatory system and organs blood and blood vessels circulatory system blood pressure

  1. Anterior mesenteric artery

  2. Coeliac artery

  3. Posterior mesenteric artery

  4. Intestinal artery

Show answer
Correct Option: B
Explanation:
The splenic artery  is the blood vessel that supplies oxygenated blood to the spleen. It branches from the celiac artery, and follows a course superior to the pancreas. It supplies oxygenated blood to the arteries.
So, the correct option is 'Coeliac artery'.

Blood vessel carrying blood from lung to heart through-

evs transportation in living organisms circulatory system and organs blood and blood vessels circulatory system blood pressure

  1. Pulmonary artery

  2. Pulmonary vein

  3. Coronory artery

  4. None of these

Show answer
Correct Option: B