Tag: cell as structural and functional unit

The cell was first discovered by Robert Hooke in 1665, which can be found to be described in his book Micrographia. In this book, he gave 60 'observations' in detail of various objects under a coarse, compound microscope. One observation was from very thin slices of bottle cork. 

Cells are called as the basic unit of life because all the living organisms are made up of cells and also all the functions taking place inside the body of organisms are performed by cells. Cells provide the specific conditions, for the occurrence of the metabolic reactions. These have the specialized enzymes, which catalyze the biochemical reaction and regulates the functions of the body.

• The cell is the basic unit of life. All the living organisms are made up of cells and each cell performs a life-sustaining process. The cell is composed of the cell membrane, cytoplasm, nucleus, cell organelles and cell wall (except animal cells). An organelle is a distinct part of a cell, which has a particular structure and function. 
• Each organelle performs a particular function. For example- mitochondria produce ATPs, lysosomes digest cellular waste and debris, centrioles separates chromosomes during cell division, Ribosome synthesizes proteins, cell wall protects, etc. 
• Due to this, a cell can survive and perform its own functions. Thus, the correct answer is option A.

• Cells are called the structural and functional unit of life because all the living organisms are made up of cells and perform all life process for survival. Unicellular organisms are made up of a single cell and single-cell only performs all the functions of life. Whereas multicellular organisms are made up of multiple cells and perform all the functions of life. Thus, the correct answer is option A.

• The basic living structure of all organisms is a cell. Cell, which was discovered by Robert Hooke in the year 1665, is considered to be the basic structural and functional unit of all the organisms. 
• Many cells combine together to form a tissue. Many tissues together form an organ. Many organs form an organ system and many different organ systems together form a human body.
• So, option cell is the structural and functional unit of all organisms and so option B.

• A group of cells, which are structurally similar and work together to perform a particular function are called tissue. 
• The collection of such tissues, which are joined in a structural unit to perform a certain function, is called an organ. Whereas cytoplasm is the living fluid in the cell. Thus, the correct answer is option A.

• All the living organism is made up of cells which constitute some organic and inorganic molecules and perform all the life process like nutrition (autotrophic or heterotrophic), reproduction (sexual or asexual), excretion. 
• Each cell arises from pre-existing cells, they divide and increase their numbers and has a certain life span, thus they undergo aging and then death. Thus, the correct answer is option D.

• In unicellular (single-celled) organisms, the single cell performs all life processes for survival such as nutrition, transport, excretion, and reproduction. 
• They do not depend on another cell for function and thus exist independently.

• Cells are called an amazing world in itself because all the living organisms are made up of cells and also all the functions taking place inside the body of organisms are performed by cells. 
• These have the specialized enzymes, which catalyze the biochemical reaction and regulates the specialized functions of the body such as the conversion of nutrients into the energy, reproduction in unicellular and division or replication in multicellular.

Robert Hooke was an English scientist who coined the term cell for the Honeycomb structures he saw in a cork slice. Through he didn't see the inside of a cell, he discovered the cell and coined the term. He used a primitive compound microscope . He only saw cell walls as it a dead tissue. He discovered it in $1665$. The first man to witness a live cell under microscope was Antonie Philips van Leeuwenhoek in $1674$.