Transportation

How much time does the heart take to pump blood?

Assertion: RBC plays an important role in the transport of respiratory gases.
Reason: RBC does not have cell organelles and nucleus.

All the reptiles have a three-chambered heart.

Which of the following animals possess a heart with two atria and a partially divided ventricle?

Fill in the blank with the correct answer from the bracket.

Most of the reptiles have a _____ chambered heart. (two, three, four)

Phloem cell wall is composed of _____ (lignin/cellulose).

Xylem has a thick wall, having parenchyma as only living cell. 

Which one of the following is correct for xylem and phloem?

Write one difference between the transportation through the xylem and phloem.

Companion cells facilitate loading of sucrose into sieve elements.

Sieve elements are living cells that conduct the starch in vascular plants.

Mature sieve elements lack _____ (nucleus/mitochondria).

'X' have valves that allow blood to flow only in one direction. These also have wide lumen. 'Y' do not have valves. Name the blood vessel 'X'.

Fill in the blank with the options provided in the bracket.

The right side of the heart contains _____ (pure, oxygenated, deoxygenated) blood.

Give reasons for the following statements.

Mature RBC in mammals does not have cell organelles.

What are the different types of blood vessels? Explain with the help of a diagram.

Give one word for the following.
Instrument used to measure blood pressure.

Blood in veins flow with _____ pressure. (high/ low)

Auricles are also known as _____ (aorta/atrium).

Soda straws and used pen refills are used to observe the internal structure of the mammalian heart.