Selective Breeding and Genetic Engineering in Biological Sciences

Running head: BIOLOGICAL SCIENCES
Biological Sciences
Name of the Student
Name of the University
Author note

1BIOLOGICAL SCIENCES
Task 2
a) Selective breeding involves choosing the parent crop plants with desired
characteristics for breeding to produce offspring with more improved characteristics
and give better yields. Improved corn plants can be produced by choosing kernels that
have the ability to grow in diverse climate and soil types. If such kernels are used
than in future favoured kernels will be reproduced repeatedly. It is because the
offspring of the selectively bred corn plants will inherit similar traits and DNA (DU et
al. 2010, Landrigan and Benbrook 2015). The same technique can be used to produce
plants with desired characteristics such as tall plants, insect resistance plants and
many other characteristics.
(Diagram of selective breeding of maize corn crops-https://infograph.venngage.com/)

2BIOLOGICAL SCIENCES
b) Genetic engineering is also called as the genetic modification involves the principle
of biotechnology to manipulate the specific plant’s gene to change the genetic
makeup by transfer of genes and produce novel plant organism. For instance, the corn
plants can be genetically cloned, by introducing the pest resistance gene (taken from
bacteria Bacillus thuringiensis) and gene for herbicide tolerance from other organism
of different species’, a process called transgenesis. Bacillus thuringiensis produces
toxins called Bt toxin that kills insects. The gene from this organism when introduced
into Corn plant using a vector called plasmid DNA of Agrobacterium tumefaciens
carrying BT gene. The corn cells are grown into culture until formation of callus. On
further treatment with hormone, these cells develop into transgenic corn plants with
integrated bacterial DNA. Therefore the corn cells are resistance to infection by
Agrobacterium responsible for the crown gall disease (Grierson 2013).