Mutations Flashcards
What are Mutations
The mistakes that occur in the copying process and the changes they bring about in the genetic code are called mutations
Causes of Mutations
Mutations occur suddenly and randomly and may be caused by many environmental agents such as X-Rays, cosmic rays, ultra-violet radiation and certain chemicals
Where do Mutations Occur
Mutations occur both in Somatic Cells as well as in Sex Cells
How Often do Mutations Occur
Because of large number of nucleotides in the DNA of most life forms, mutations occur more frequently than most of us think they do
Gene Mutations
A gene mutation refers to a change in the structure of a gene as a result of a change in the DNA sequence
Chromosomal Aberrations/ Chromosomal Mutations
Chromosomal aberrations refers to changes in the normal structure or number of chromosomes
Harmful Mutations
Harmful mutations are normally referred to as lethal mutations: the mutated organism dies and the harmful characteristics are not passed onto the next generation
Neutral Mutations
They have no effect on the structure or functioning of the organism which possesses them
Advantageous Mutations
Beside being harmless, a few mutations may be advantageous to the organism and they are passed on from one parent to offspring. Sometimes the advantageous mutant gene wipes out all the other alleles controlling the same characteristics within the population. We refer to these as Fixed Mutations
Sex Chromosomes and Sex Determination
Each species has its own characteristic number, shape and size of chromosomes in each somatic cell. This is called its Karyotype
Inheritance of Sex-Linked Characteristics
The gene for most bodily characteristics are located on the 22 pairs of autosomes. In addition to determining sex, the sex chromosome/ gonosomes also contain genes for certain bodily characteristics. Since the genes for these characteristics are located on the sex chromosome, we call them Sex-Linked Characteristics
Genetic Disorders caused by Mutations
Down Syndrome
Sickle-Cell Anaemia
Haemophilia
Albinism
What is Genetic Engineering
Genetic Engineering also called genetic modification is the deliberate modification of the characteristics of an organism by manipulating its genetic material, using biotechnology
What is Biotechnology
Biotechnology is the use of biological processes, organisms, or systems to manufacture products intended to improve the quality of human life
