QCM : Fundamentals of Cell Biology — 5 questions

Explication

Rudolf Virchow is credited with proposing the concept that all cells come from pre-existing cells, which is a fundamental principle of cell biology. This idea was a key advancement in the development of the cell theory, complementing the work of Schleiden and Schwann who recognized that all organisms are made of cells. Louis Pasteur contributed to germ theory, and Robert Hooke was among the first to observe cells, but did not formulate the idea that all cells originate from pre-existing cells.

Explication

Mitochondria are the organelles responsible for producing energy through respiration, making them directly responsible for meeting increased energy demands in the cell. The nucleus controls cell activities via genetic instructions, ribosomes synthesize proteins, and the cell wall provides structural support but does not produce energy.

Explication

DNA polymerase is the enzyme that synthesizes new DNA strands during replication by adding nucleotides in the correct sequence. Helicase unwinds DNA, ligase joins DNA fragments, and topoisomerase relieves supercoiling; none of these directly synthesize DNA.

Explication

Chromosomes are structures that contain DNA, which carries genetic information. During cell division, chromosomes ensure that each daughter cell receives an identical set of genetic instructions, making their primary role to carry genetic information.

Explication

Watson and Crick published their model of the DNA double helix in 1953, which was the first description of DNA's structure. The other dates correspond to different important events in genetics: 1944 is around when Griffith's transformation experiments were conducted, 1961 is when Nirenberg and Matthaei deciphered the genetic code, and 1977 is when DNA sequencing methods like Sanger sequencing were further developed.