Question

The figure given below shows the structure of animal cells. Which letter represents mitochondria?

A) P
B) M
C) N
D) O
E) None of these

Answer 1

Animal cells are called eukaryotic cells which contain the nucleus. It is different from the plant cells but doesn't have cell walls. Mitochondrion is a double membrane organelle in animal cells which is mostly available in eukaryotic cells. Animal cells are seen in animal tissues. It is a basic unit in an animal cell. It has a nucleus. There are different types of animal cells. They do different jobs like carrying oxygen by blood cells and collect $C{O_2}$.

Complete answer:
Option A represents P: P implies a nuclear membrane. It is the double membrane which encloses the nucleus of the cell. It is used to separate chromosomes from other cells. This nuclear membrane has small holes and pores. This is used to pass the nucleic acid and proteins from the nucleus and cytoplasm. It has an outer part called endoplasmic reticulum. It is also called a nuclear envelope. It protects the DNA of a cell from chemical reaction.
Hence option A is incorrect.
Option B represents M: M implies nucleolus. It is the largest structure in the nucleus. Nucleolus is a dynamic membrane less structure. The main duty of nucleolus is ribosomal RNA synthesis and ribosome biogenesis. It will enlarge during protein synthesis. It is a round cell made by proteins.
Hence option B is incorrect.
Option C represents N: N implies Golgi apparatus. It is used to pack proteins, lipid molecules. It is made by a flattened cisternae in a series manner. It transports, modifies and packs proteins and lipids to the destination.
Hence option C is incorrect.
Option D represents O: O implies mitochondria. It generates a large amount of adenosine triphosphate which is used as a source of energy. It used to power the cells during biochemical reaction by providing the energy. This is produced energy stored in a small molecule called adenosine triphosphate. It is called a powerhouse of the cell. Biochemical process of a cell is called cellular respiration. The main duty of mitochondria is to produce energy to the cell, ATP, regulate cellular metabolism. The size of this one is $0.5{\text{ }} - {\text{ }}1.0$ micrometer. It has an outer and inner membrane which is made by proteins. It contains its own DNA and it encodes tRNAs, rRNAs and some protein.
Hence option D is correct.

Therefore, Option D is the correct answer.

Note:
Different types of animal cells are muscle, blood, skin, fat and nerve. There are two types of cells available. They are prokaryotic cells and eukaryotic cells. Animal cells have membrane bounded organelles which are in cytoplasm surrounded by plasma membranes. It has an irregular shape. It also has a centrosome, lysosome. It gives shape to the cell and provides strength. It also provides mechanical support for cells to move and divide processes.