Sex-linked inheritance
Characters:
Theme: Mendelian genetics problem solvingMendelian genetics problem.
Competencies
Mathematical competence in science, technology and engineering
Personal, social and learning to learn competence
Competence in cultural awareness and expressions
Subjects and year by Educational System
Spain > Biology and geology > 4th ESO > Genetic and evolution
Enunciation
Nettie Maria Stevens was the first scientist to describe the chromosomal basis of sex. In mammals, females have identical sex chromosomes called X, and males have an X chromosome and a smaller Y chromosome.
Hemophilia is characterized by the difficulty of individuals in clotting blood. The disease is determined by a gene (h) present on the differential segment of the X chromosome that is recessive to its normal allele (H).
Observe the following family tree of the English royal family and answer what will be the genotype of:
a) Queen Victoria.
b) Prince Albert.
c) Alfonso XIII, King of Spain.
d) Alfonso, Prince of Asturias.
e) Juan Carlos I, king of Spain.
f) Infanta Cristina
g) Prince Felipe
Observations and context
In 1905, Nettie Stevens published a study that would revolutionize the world of science. Her work demonstrated that sex was determined by specific chromosomal bases. Nettie had worked all her life to make a place for herself in the complicated and sexist scientific community at the dawn of the 20th century. Although she was eventually given the recognition she deserved, her scientific work was called into question. These difficulties in finding the recognition that women scientists deserve have continued to be reproduced almost to the present day.
A century later, in 2006, upon the death of the renowned microbial geneticist Esther Lederberg, the respected molecular biology professor Dr. Stanley Falkow stated in his farewell speech regarding the unfair treatment of women scientists: "Martha Chase (1927-2003), Daisy Roulland-Dussoix (1936-2014) and Esther Lederberg (1922-2006) were women who made crucial discoveries in science".
Martha Chase demonstrated that the hereditary material of bacteriophages is DNA and not proteins.
Daisy Dussoix discovered restriction enzymes.
Esther Lederberg invented plate replication.
Each of these discoveries has been assigned to a male member of the research group (Alfred Hershey, Werber Arber and Joshua Lederberg, respectively). Likewise, as a final colophon of his speech the scientist added: "Historians would do well to review the science of the mid-20th century, a time of great contributions, but also of enormous discriminations."
Description
Mendelian genetics problem.