In the 1940's, while studying genetic inheritance in corn plants, Barbara McClintock discovered that segments of DNA could move
from one place to another on a chromosome and even move from one chromosome to another. The moving segments cause genetic variation and some changes are suspected to cause such genetic disorders as breast cancer and leukemia. McClintock received a Nobel Prize for her work in genetics. These movable segments are now called A) DNA sequencing. B) recombinant DNA. C) transposons or jumping genes. D) transgenic or McClintock plasmids.
The correct answer is option (C) transposons or jumping genes.
Barbara McClintock was an american cytogeneticist. In 1940s, she discovered the phenomenon of transposition brought about by the mobile genetic elements or jumping genes or the transposable elements. These jumping genes refers to a sequence of DNA which can change its position in the genome or the genetic constitution of an organism. She discovered these jumping genes in the Maize for the first time and received the nobel prize in 1983.
Jumping genes form a major portion of the eukaryotic genome. They are often responsible for mutations and associated with the duplication of the genetic material. They also cause the structural changes in the chromosomes like inversion, deletion and translocation which are called the chromosomal aberrations.
The introduction of new species in the new area make the specie invasive if there is no predator is present in that ecosystem because the predator helps in the controlling of the population of that invasive species. The big example of invasive species is rabbit in the Australia where rabbit become invasive when there is no predator is present in that region so they increase in population and destroy all vegetation of that region. So if there is no predator of a newly introduced species, it become invasive in future.
