Question

Freemartin is an example of
(a) Hormonal controlled, unlike sex twins
(b) Sex reversal by genes
(c) Environmental control of sex
(d) None of the above

Answer 1

Hint: Freemartin is a type of syndrome that causes sexual abnormalities in cattle. The female which produced after fertilization is infertile with non-functioning ovaries. The Characteristics of a freemartin female is similar to male with high masculinized development.

Complete answer:
A freemartin is an example of hormonal controlled unlike sex twins, which take place by exchange of some cellular material and male hormone testosterone through the placenta from male twin to female. Phenotypically the animal originates as female with the genotype of male (XY). It does not take place if the twin is of the same sex because in the case of a same-sex exchange of material does not cause any effect in the fetus. The ovaries of freemartin remain small without the production of the hormone, the vulva is normal with a large tuft of vulvar hair which protects it from heat.

Additional Information: Freemartin generally practiced to obtain stem cells and for immunological research. Freemartin resembles mostly the male twin because 95% of its blood has components similar to the male twin. Blood of freemartin helps in the analysis of healthy and unmanipulated animals without restoration for transplantation. The diagnosis of this takes place through genetic testing and physical examination.
A freemartin is also found in sheep, goats, and pigs.
So, the correct answer is ‘Hormonal controlled, unlike sex twins’.

Note: In the ten percent case, the passage of cellular material does not take place from male to a female twin, by which the female remains fertile. In the case of a freemartin, males remain unaffected with a slight reduction in testicles which cause a reduction in bull fertility.