Question

Which scientist discovered sex determination in Melandrium album?
A. H.E. Warmke
B. R.P Roy
C. C.B Bridges
D. Wilson and Stevens

Answer 1

Hint: For the sex determination in Melandrium album, Y chromosomes play a crucial role. It contains male determining genes and female suppressing genes which are necessary for the maturation and development of potent anthers in the plants.

Complete Answer:
- Melandrium album (2n=24) is a dioecious species with hetromorphic sex chromosomes represented as (XY in males and XX in females). Through the microscopic study was seen that the chromosomes in males differed in appearance to that of females. The chromosome which was similar to both males and females was identified as X and the one in male was identified as Y.
- This was proposed by H.E. Warmke. He said that AAXX will be the chromosomal constitution of females and AAXY for the males irrespective of the ploidy of the chromosomes i.e. the plants can be diploids, triploids or tetraploids.Thus the chromosome constitution in males can be XY, XXY, XXXY, XXXXY. The males with XXXXY chromosomes are hermaphrodite which means one Y is equal to 4X.
- R.P Roy- He is known for his studies in protein engineering.
- C.B Bridges- He studied non-junction for the chromosome theory of heredity in Drosophila.
- Wilson and Stevens- They studied that the sex is determined by a particular configuration of chromosomes.

Thus the correct answer is (A). H.E. Warmke discovered sex determination in Melandrium album.

Note: Sex determination is a system of determination of sexual character of an organism. In the case of the Melandrium album, the Females are represented as XX and the males as XY. Y chromosome is the sex determining chromosome.