Question

Which of the following are epidermal appendages?
A) Trichome
B) Guard cell
C) Sclereid
D) Subsidiary cells

Answer 1

Epidermis is generally the outer layer of cells in a tissue. Appendages would be parts of these cells, or outgrowths, that extend out into the environment surrounding the epidermis. Various kinds of hairs are included in this category.

Complete answer:
Option (A) is the correct answer. There are several types of epidermal appendages which are referred to as trichomes. Trichomes are also known as epidermal hairs, which is self-explanatory. These appendages are found on the surfaces of parts that are exposed to the air. Their function is to protect the plants from all kinds of stresses including water loss, high temperatures, defence against insect pests, and even pathogens. Sometimes these structures may be scalier or bud like, instead of fine like cilia.
(B) is an incorrect option, Guard cells are found as part of the stomata. Through their opening and closing they regulate water loss and allow for entry and exit of respiratory gases.
(C) sclereids are a type of sclerenchyma cell, not epidermal. Thy ear found in xylem and phloem, in pith, and seeds. They provide support to plants and prevent desiccation of seeds.
(D) is also incorrect as Subsidiary cells are epidermal cells, not appendages. They are located next to the guard cells in the leaves of plants.

Hence the correct answer is OPTION(A)

Note: One kind of trichome, the glandular variety, are responsible for the production of various resins which are used widely in pharmaceutical, cosmetic, and even agricultural industries. For instance, to make capsules for medicines.