Explanation

• Volvox is a genus of green algae that includes about 20 species of aquatic, photosynthetic organisms.
• They are characterized by their spherical or ellipsoidal shape and are typically found in freshwater environments.
• Volvox species are known for their unique colony structure, which consists of a hollow sphere of cells surrounding a central cavity.

Explanation

• Rana tigrina, also known as the Asian giant toad or the Indian bullfrog.
• It is a species of frog found in Southeast Asia and the Indian subcontinent.

Explanation

• Platelets, also called thrombocytes.
• They are blood cells that play a vital role in blood clotting.
• When a blood vessel is injured, platelets aggregate to form a plug that stops the bleeding.

Explanation

The melting point of ice at normal atmospheric pressure is 0 °C (zero degrees Celsius).

Key Points:

• 0 K (zero Kelvin) is equivalent to -273.15 °C, which is absolute zero, the lowest possible temperature.
• 100 °C is the boiling point of water at normal atmospheric pressure.

Explanation

• In the human heart, blood returning from the lungs via the pulmonary veins drains into the left atrium.
• From there, it flows through the mitral valve into the left ventricle, which pumps it out to the rest of the body through the aorta.