Question

Name the scientists who have contributed to the following:

1. Reverse transcription.
2. Photorespiration.
3. Principle of limiting factors.
4. Photolysis of water.

Answer 1

Reverse transcription:

1. An enzyme that is found in retroviruses converts the RNA genome into double-stranded DNA.
2. In 1970, David Baltimore and Howard Temin discovered the reverse transcriptase, independently and simultaneously.
3. The discovery of this enzyme led to the discovery of oncogenes, the discovery of human cancer cells, and the treatment of HIV-AIDS.

Photorespiration:

1. Photorespiration is the process in which the oxidation of glycolic acid takes place and as a result, carbon dioxide is released under some environmental conditions and inhibits the process of photosynthesis.
2. This process tends to happen in higher plants.
3. Photorespiration was first discovered by Decker and Tio.

Principle of limiting factors:

1. Several external factors affect photosynthesis.
2. Such factors are sunlight, the concentration of water, CO₂, and temperature.
3. Blackman's principle of limiting factors states that if any one of the external factors is at its sub-optimal state then the process of photosynthesis will not occur.
4. Example: If the sunlight and CO₂ are in sufficient amount but the temperature is very low, photosynthesis will not take place.

Photolysis of water:

1. Photolysis of water or also known as the splitting of water is part of the light reaction.
2. In this reaction, the electrons from the water are transferred to an electron acceptor.
3. This reaction was first studied by Robert Hill in 1937, by isolating the chloroplast from the leaf.