Question

Robert Hooke actually observed _________of cells
(a) Cell wall
(b) Protoplasts
(c) Wall-less cells
(d) Walled cells

Answer 1

Hint: It is a structural layer of a cell. It has a sieving mechanism and it is present in both the plant and animal cells. It generally consists of three layers in plant cells. Its characteristics differentiate the plant and animal cells. It provides mechanical supports to the cells.

Complete step by step answer:
- Hooke is best known for his identification of the cellular structure of plants.
- He was observing birds feathers, weather, insects, and fossils, and plants. Once he was observing a thin slice of cork under the microscope he noticed some perforated and porous and much honeycomb- like structure and he named those structures as a cell and those were actually a non- living rigid structure.
- Robert Hooke published his first book called” Micrographia” describing observation made through a microscope.
So, the correct answer is, “cell wall”.

Additional information:
- Outer covering of the plasma membrane is covered by a cell wall ( fungi and plants) .
- Cell wall is responsible for the shape of the cell and also provides rigidity and mechanical support to the cell, protecting it from damage.
- Protoplast: are the plant cells whose cell wall is removed usually by digestion of enzymes.
- Wall less cells: are the cells that lack a cell wall. An example of bacteria that lack a cell wall is mycoplasma and L- form bacteria.
- Walled cells: are the cells having a cell wall. example- algae have cell walls made of cellulose, Galatians, mannans, and minerals like calcium carbonate while in other plants it consists of cellulose, hemicellulose, pectins, and proteins.

Note: In young plants - the cell wall consists of two walls - Primary walls and Secondary walls. The primary cell wall is efficient in growth and slowly disappears when the cell matures. Secondary wall present on the inner side of the membrane.