Question

What is the characteristic feature of an animal cell?
(a) Absence of cell wall
(b) Presence of only cell membrane
(c) Absence of plastid
(d) All the above

Answer 1

Hint: Nearly all cells are similar in structure and function in the case of eukaryotic cells but the animal cells show some dissimilarities with the rest of the cells mainly due to the absence of cell wall and also due to the absence of some cell components.

Complete Answer:
Due to the absence of a cell wall, animal cells are smaller than the rest of the cell. It only consists of a cell coat which is also known as glycocalyx and plasma membranes outside the cell which are thin and flexible and due to this, it shows different types of shape. The cell coat is made up of oligosaccharides and helps to protect the plasma membrane by recognising microbes and body cells for defence. Plastids are absent because the animal does not show photosynthesis nor it store food and the size of the vacuole is also very small as compared to plant cells. The nucleus is present in the centre whereas the Golgi complex consists of the single connected complex. A lysosome is present as it helps in digestion with the help of digestive enzymes or hydrolysing enzymes but glyoxysomes are absent because it is common in germinating oilseed. Reserve food is present in the form of mainly glycogen and fat which gives energy to the body during starvation.

So, the correct answer is 'All the above'

Note:
In some cells, the glycocalyx is strengthened with the help of calcium salt and silicon deposition, which gives a definite shape to the cell. The glycocalyx of erythrocytes consists of antigens which help to form the basis of the blood group.