Transportation in Plants and Animals - 3

O blood group does not have any antigen, but possesses both A and B antibodies.

Parents belong to blood group A and B. Blood group of their child can be A, B, O or AB.

The medium of plasma is basic as its pH is 7.4.

Turgor pressure helps to maintain the turgidity of cells.Healthy plant cells are turgid and plants rely on turgidity to maintain rigidity.

The pulmonary artery carries impure blood to lungs.It is one of the only arteries (other than the umbilical arteries in the fetus) that carries deoxygenated blood.

Option (1) is the correct answer.

Ascent of sap takes place in the lumen of tracheary element in xylem of a plant.

In mammals, the role of spleen is to assist the liver.The spleen acts as a blood filter; it controls the amount of red blood cells and blood storage in the body, and helps to fight infection.

If the heart is cut out from the body of a frog, it will continue beating for a long time if it is kept moist. The poikilotherm heart has a built-in pacemaker (a group of neural cells sending out regular impulses) allowing the heart to beat for hours even after the brain is no longer connected to the heart.

Leukopenia is the condition when the total number of leukocytes decreases below 5000 per cubic mm. Leukopenia can be identified with a complete blood count..

The atrioventricular node is located on the right side of interauricular septum.

The phase of contraction of the heart is termed as systole.

The mitral (bicuspid) valve in mammals guards the opening between left atrium and left ventricle. It has two flaps. 

Conduction of water and minerals is the main function of xylem vessels.Vessel elements are typically found in flowering plants (angiosperms) but absent from most gymnosperms such as conifers. Vessel elements are the main feature distinguishing the "hardwood" of angiosperms from the "softwood" of conifers.

Excessive transpiration and reduced absorption causes hot weather wilting in plants.

The weight of heart of men varies from 280 to 340 g. In woman, it varies from 230 - 280 g.

If the pace maker is absent, cardiac muscles will contract in a coordinated manner because pace maker sets the rhythmic contractions.

Option (1) is the correct answer.  Antigen-antibody reaction is a specific chemical interaction between antibodies produced by B cells of the white blood cells and antigens during immune reaction.

Option (1) is the correct answer. Lymph nodes are major sites of B, T and other immune cells.

Option (4) is the correct answer. The atrioventricular node is a part of the electrical conduction system of the heart that coordinates the top of the heart.