Practice MCQ Questions and answers on Biology-GK

Cell theory was formulated by two scientists: Theodor Schwann and Matthias Jakob Schleiden.

Lysosomes are found in animal cell, they are also known as suicidal bags of the cell. A human cell contains around 300 lysosomes. They not only digest large molecules but also responsible for breaking down and getting rid of waste products of the cell. They have enzymes which allow them to carry out these processes.

The common features of prokaryotic and eukaryotic cells are: DNA, the genetic material contained in one or more chromosomes and located in a non membrane bound nucleoid region in prokaryotes and a membrane-bound nucleus in eukaryotes.

Mitochondria contain enzymes for cellular respiration. Mitochondria are known as the powerhouse of the cell.

The cell is the smallest structural and functional unit of living organisms, which can exist on its own. Therefore, it is sometimes called the building block of life.

Ribosomes are protein-making factories found in all cells, from humans to bacteria. The ribosome will scan down the RNA, like a train going down tracks, adding in amino acids to the protein being produced. When the ribosome reaches the end of the RNA, the protein is released. This process is called translation.

In 1833, Brown observed and described the nucleus, the first organelle. In 1838, the many and various observations were converted into a cell theory by Schleiden, who proposed that all plant tissues were composed of nucleated cells.

The cell was discovered by Robert Hooke.

Work on mitochondria did not stop in the 1950s after it was named “the powerhouse of the cell.”

Credit for developing cell theory is usually given to three scientists: Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow. In 1839, Schwann and Schleiden suggested that cells were the basic unit of life.