Correct answer is Mycoplasma – Monera.

Think of Monera as a group of very tiny and simple organisms that do not have a proper nucleus. Mycoplasma is one of the smallest living organisms and belongs to this group. Cyanobacteria are also Monera, not Protista. Diatoms are more complex and belong to Protista. Yeast is a fungus, so it belongs to Fungi, not Protista. That is why only option B is correct.

Correct answer is They are obligate intracellular parasites.

Viruses are not fully living like plants or animals. They can only grow and multiply inside a living host cell. Outside the host, they remain inactive and do not show life processes. They have only one type of genetic material—either DNA or RNA, not both. They cannot reproduce on their own like bacteria. That is why they are called obligate intracellular parasites.

Correct answer is All animals, living and extinct. Zoology is the branch of biology that studies the structure, behavior, and evolution of all animals, both living and extinct.

Correct answer is Jointed appendages.

Arthropoda is a group of animals like insects, spiders, and crabs. They have a hard outer covering and special legs with joints. These jointed appendages help them move easily.

Other options are wrong because:
Notochord is in humans (Chordates).
Radial symmetry is in starfish.
Arthropods have a body cavity (coelom).
So, the correct answer is jointed appendages.

Correct answer is Reptilia and Aves. Archaeopteryx shows characters of both reptiles and birds.

Correct answer is Ovary.

In a flower, the ovary is the swollen base part that contains ovules. After fertilization, this ovary develops into a fruit.

The ovules are small structures inside the ovary and they become seeds. Petals attract insects and sepals protect the flower bud.

After fertilization, petals and sepals usually fall off. So, the ovary forms the fruit.

Correct answer is Whale. The blue whale is the largest mammal ever known.

Correct answer is Nitrogen.

Plants need nutrients to grow properly. Macronutrients are required in large amounts. Nitrogen is one such important nutrient that helps in protein formation and growth.

Iron, zinc, and copper are needed in very small amounts, so they are called micronutrients. Hence, nitrogen is the correct answer.

Correct answer is Whale. Whales are warm-blooded mammals.

Correct answer is Sperm whale. It is the largest toothed whale species.