Question
Question: The term chromonema was coined by: A. Flemming B. Strasburger C. De robertis D. Vijdovsky...
The term chromonema was coined by:
A. Flemming
B. Strasburger
C. De robertis
D. Vijdovsky
Solution
Chromosomes are thread like structures which are visible only during cell division. These chromosomes are made up of proteins and a single DNA molecule. The protein is known as the histone protein. It is this chromosome that is passed from the parents to the offspring.
Complete answer:
To know the correct answer to the question, we must be well aware of chromonema.
Chromonema is a spirally coiled core of the chromosomes on which the genes are located. During the prophase of mitotic division, the chromosome material appears as thin filaments. These thin filaments are known as chromonema.
These chromonema represent the chromatids in the early stages of condensation.
Flemming is known to be the founder of cytogenetics. He discovered and named the chromatin. Flemming also discovered mitosis in animal cell
He was the first to describe the embryo sac of the gymnosperm and angiosperm. He also demonstrated the double fertilization in gymnosperm.
Strasburger discovered mitosis in a plant cell.
De Robertis was a zoologist who discovered the tissue differentiation in zygote when zygote transforms into an adult.
This term was first used by Vijdovsky in 1912.
Since now we are well aware of the chromonema therefore the correct answer to the question is option D. i.e Vijdovsky.
Note: Here it must be noted that the centromere is the constriction which is located on the chromosome and to which the arms of the chromosomes are attached. The coiling of the DNA threads gives rise to bead like structures known as the chromomeres. The centromere and the chromomere must not be confused with the chromonema.