Question

Accretionary growth is due to
A. Reserve cells
B. Meristematic cells
C. Embryonic cells
D. Differentiated cells

Answer 1

Hint: Growth is usually said to be not defining property. The growth is defined as an increase in the body size and number of cells. Growth is exhibited by both living and non living organisms. So it is said that growth is not a defining property of organisms.

Complete answer:
The accretionary growth occurs in the adult stage . It also occurs during the post embryonic stage . This type of growth occurs when cells become permanent . They are not in the stage of division .
Reserve cells :- when cells become permanent in their structure and function no new formation takes place. But at some locations some cells are present that form the function of replacing the old cells so accretionary growth occurs . Thus this option is correct.
Meristematic cells :- these cells have the ability to divide again and again and leads to the formation of new structures but during accretionary growth no new cells are formed . Thus this option is not correct.
Embryonic cells :- the cells present in embryos divide to form new structures and also give rise to the organs . But in accretionary growth cells do not divide and some cells divide to replace dead tissues . Thus this option is also not correct.
Differentiated cells :- the cells which have undergone division to form new structure are called as differentiated cells for once they become permanent but then again they differentiate and divide further But in accretionary growth cells do not divide and some cells divide to replace dead tissues . Thus this option is also not correct.

Our required answer is A)Reserve cells.

Note: The accretionary growth can be seen in bone and cartilage. In this type cells lose their capacity to divide so there will be necessity of secretion of extracellular matrix for growth. Some more types of growth can be seen in organisms like auxetic growth which is characterised by the increase in the cell of size as is nematodes.