Cell Structure and Functions Test - 18

• The cells are microscopic in size and are not visible to the unaided eye with the size from 0.5 micrometers to 50 micrometers. 
• They need to be enlarged or magnified by a microscope. 
• The electron microscope discovered by Knoll and Ruska was able to magnify the cellular structure.

Cytoplasm is a thick solution that fills each cell. It is enclosed by the cell membrane. It is made up of water, salts and proteins. Organelles of cells are present in the cytoplasm. Cytoplasm is the jelly-like substance present between the cell membrane and the nucleus.

Plant and animal cells are both eukaryotic cells, so they have several features in common, such as the presence of a nucleus with nuclear membrane and membrane-bounded organelles.

Cells can be prokaryotic or eukaryotic. If the cells have dispersed nucleus i.e., nucleoid then these are called as prokaryotic cells. Eukaryotes are organisms, whose cells are organized into complex structures by internal membranes and a cytoskeleton.
So, the correct answer is option C.

• The first characteristic of a living thing is that they are made up of cells. A cell is a basic building block of all organisms. 
• It is the smallest unit of organization in a biosphere. A cell performs the life process to maintains the survival of an organism.

Correct Option: B

Explanation:

• The cells are the basic structural, functional and biological unit of all known living organisms. 
• Cells are the smallest unit of life that can replicate independently and are often called the building blocks of life. 
• The human body is composed of trillions of cells. 
• They provide structure for the body, take in nutrients from food, convert those nutrients into energy and carry out specialized functions. 
• Cells also contain the body's hereditary material and can make copies of them.

The cell is the structural unit of life. Unicellular organisms are made up of one cell that performs all the functions and thus, called as a single-celled organism.

• Organisms can consist of one cell to many cells. 
• The cell is the structural unit of life. Unicellular organisms are made up of one cell that performs all the functions.
•  Whereas, a multicellular organism that consists of multiple cells and a different group of cells perform different functions which give complexity to the multicellular organisms.

The DNA is the genetic material of the organism which is present in the nucleus. It is seen in chromosomes.