Point 1 of 7 — Lesson 1: Identification of DNA as Genetic MaterialQuestion bank: 6 questions (6 with pictures)
01The question
Observation of dividing cells shows that the chromosomes of the nucleus separate and every daughter cell ends up with the same number of chromosomes as the original.
That strongly suggested chromosomes carry the hereditary information.
But a chromosome is made of two substances: DNA and protein.
Which one is the genetic material?
At first, proteins looked like the better candidate.
Genes have to hold a huge variety of instructions; proteins are a diverse, complex group built from 20 different amino acids that can be combined in endless sequences, whereas DNA seemed to have only four kinds of nucleotide.
Scientists therefore expected the proteins to carry the information.
By the 1940s, experiments showed this was wrong: DNA carries the genetic information.
This discovery launchedmolecular biology, the study of the molecular basis of inheritance.
📝 Question bank for this point
6 questions linked to this point only, 6 of them with pictures.
