Question

Theory of heterogamesis for sex determination was proposed by.
A. Morgan
B. Darwin
C. Correns
D. Bridges

Answer 1

Sex-determination is a biological system that regulates the development of characters in an organism. Organisms that gave rise to their offspring using sexual reproduction have two sexes. Males and females have different alleles or even different genes that specify their sexual morphology.

Step by step answer: In word heterogamesis it consists of two words hetero and gamesis. The word hetero means different and gamesis means related to gametes. In sex determination, when organisms produce different kinds of gametes in the different sex then that particular case is known as heterogamesis. In this male and female gametes differ from each other.
Option A: Thomas Morgan is the famous scientist who proposed the linkage and recombination by studying on the drosophila.
Option B: Darwin gave the theory of natural selection which is related to evolution.
Option C: Correns gave the theory of heterogamesis for sex determination. This theory was based on the number of chromosomes and nature of allosomes. He also discovers the cytoplasmic inheritance which is the particular case of the maternal inheritance. He discovers the maternal inheritance in the plant known as Mirabilis Jalapa.
Option 4: Bridges contribution among Drosophila researchers is his observation and documentation of the polytene chromosomes found in larval salivary gland cells. The banding patterns of these chromosomes are still used as genetic landmarks.
So, the correct option is option C, i.e.,Correns.

Note: Heterogametic sex described as the sex of a species in which the sex chromosomes are not the same. For example, in humans males are having X and Y sex chromosome, would be referred to as the heterogametic sex, whereas females having two X sex chromosomes would be referred to as the homogametic sex.