Cell Biology Interview Preparation Guide Add New Question

Cell Biology Interview Questions and Answers will teach us now that The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular. So learn every thing about the Cell Biology with this Cell Biology Interview Questions with Answers guide

110 Cell Biology Questions and Answers:

1 :: What is the difference between plasma membrane and cell wall?

Plasma membrane and cell wall is not the same thing. Plasma membrane, also called cell membrane, is the outer membrane common to all living cells and it is made of a phospholipid bilayer, embedded proteins and some appended carbohydrates.

Because cell membranes are fragile, in some types of cells there are even outer structures that support and protect the membrane, like the cellulose wall of plant cells and the chitin wall of some fungi cells. Most bacteria also present an outer cell wall made of peptidoglycans and other organic substances.

Cell Structure Review - Image Diversity: cell wall

2 :: What are the chemical substances that compose the plasma membrane?

The main constituents of the plasma membrane are phospholipids, proteins and carbohydrates. The phospholipds, amphipathic molecules, are regularly organized in the membrane according to their polarity: two layers of phospholipids form the lipid bilayer with the polar part of the phospholipids pointing to the exterior of the layer and the non polar phospholipid chains in the interior. Proteins can be found embedded in the lipid bilayer and there are also some carbohydrates bound to proteins and to phospholipids in the outer face of the membrane.

3 :: Do bacteria cells have nucleus?

In bacteria the genetic material is dispersed in the cytosol and there is no internal membrane that delimits a nucleus.

4 :: Is there any bacteria made of more than one cell?

There are no pluricellular bacteria. All bacteria are unicellular prokaryotic.

5 :: What is the plasma membrane of the cell? What are its main functions?

The plasma membrane is the outer membrane of the cell it delimits the cell itself and a cell interior with specific conditions for the cellular function. Since it is selectively permeable the plasma membrane has an important role for the passage of substances inwards or outwards.

Cell Structure Review - Image Diversity: cell membrane

6 :: What are the two big groups into which cells are classified?

Cells can be classified as eukaryotic or prokaryotic.

Prokaryotic cell is that without a delimited nucleus. Eukaryotic cells are those with nucleus delimited by membrane.

Cell Structure Review - Image Diversity: eukaryotic cell prokaryotic cell

7 :: In 1665 Robert Hooke, an English scientist, published his book Micrographia, in which he described that pieces of cork viewed under the microscope present small cavities similar to pores and filled with air. Based on later knowledge of what were the walls of those cavities constituted? What is the historical importance of that observation?

The walls of the cavities observed by Hooke were the walls of the plant cells that form the tissue. The observation leaded to the the discovery of the cells, a fact only possible after the invention of the microscope. In that work, Hooke established the term “cell”, now widely used in Biology, to designate those cavities seen under the microscope.

Cell Structure Review - Image Diversity: Hooke's cell

8 :: Are there living beings without cell?

The virus is considered the only alive beings that do not have cells. Virus are constituted by genetic material (DNA or RNA) enwrapped by a protein capsule. They do not have membrane and cell organelles neither self-metabolism.

9 :: What is the cell theory?

Cell theory is a theory that asserts that the cell is the constituent unit of the living beings.

Before the discovery of the cell, it was not recognized that the living beings were made of building blocks like cells.

The cell theory is one of the basic theories of Biology.

10 :: What are the main respective constituents of cell walls in bacteria, protists, fungi and plants?

In bacteria cell wall is made of peptidoglycans; among protists algae have cell wall made of cellulose; in fungi, the cell wall is made of chitin (the same substance that makes the exoskeleton of arthropods); in plants, the cell wall is made of cellulose too.
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