A mutation is any change in a DNA sequence that can be passed from parent to offspring. By inducing mutations,
scientists have been able to increase genetic variation
, which breeders depend on to produce crops with desirable traits, such as resistance to diseases and insects.
Is it easy for breeders to produce mutants with desirable mutations?
Is it easy for breeders to produce mutants with desirable mutations? …
No, many mutations are harmful
, and it requires luck and perseverance to produce a few mutants with desirable characteristics that are not found in the original population.
How can breeders introduce mutation?
Most mutation breeders induce random changes in DNA
by using ionizing radiation or mutagenic chemicals, such as ethyl methane sulfonate
, to increase the rate and frequency of the mutation process. In spite of these intrusive methods, induced mutagenesis is considered a conventional breeding technique.
Does selective breeding change DNA?
Selective breeding is a form of genetic modification which doesn’t involve the addition of any foreign genetic material (DNA) into the organism. Rather, it is
the conscious selection for desirable traits
.
What is the relationship between genetic variation and mutations?
Genetic variation refers to diversity in gene frequencies. Genetic variation can refer to
differences between individuals or to differences between populations
. Mutation is the ultimate source of genetic variation, but mechanisms such as sexual reproduction and genetic drift contribute to it as well.
How do physical mutagens cause mutations?
Physical mutagens most often result
in chromosome changes and larger DNA deletions
while mutagenic chemicals typically cause point mutations. The degree of mutation also depends on the tissue and the time and dosage of exposure. DNA mutations are generally of the most interest to breeders.
What is induced mutation give example?
Induced mutations are alterations in the gene after it has come in contact with mutagens and environmental causes. Induced mutations on the molecular level can be caused by:
Chemicals
.
Hydroxylamine
.
Base analogs
(e.g., Bromodeoxyuridine (BrdU))
What are 4 examples of selective breeding?
- cows that produce lots of milk.
- chickens that produce large eggs.
- wheat plants that produce lots of grain.
Why is selective breeding bad?
Risks of selective breeding:
reduced genetic variation can lead to attack by specific insects or disease
, which could be extremely destructive. rare disease genes can be unknowingly selected as part of a positive trait, leading to problems with specific organisms, eg a high percentage of Dalmatian dogs are deaf.
Is GM faster than selective breeding?
Benefits of genetic engineering:
Genetic modification is a
faster and more efficient way of getting the same results as selective breeding
.
What causes mutation?
Mutation. A mutation is a change in a DNA sequence. Mutations can result from
DNA copying mistakes made during cell division
, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses.
What are the 3 sources of mutations?
- Base Substitutions. Single base substitutions are called point mutations, recall the point mutation Glu —–> Val which causes sickle-cell disease.
- Deletions. …
- Insertions.
What is an example of mutation in evolution?
Even deleterious mutations can cause evolutionary change, especially in small populations, by removing individuals that might be carrying adaptive alleles at other genes. Figure 2: The history of the
gray treefrog, Hyla versicolor
, is an example of mutation and its potential effects.
What are physical mutations?
1: Three Types of Point Mutations. The chemical or physical agents that cause mutations are called mutagens. Examples of physical mutagens are
ultraviolet (UV) and gamma radiation
. Radiation exerts its mutagenic effect either directly or by creating free radicals that in turn have mutagenic effects.
What are 2 examples of mutagens?
Examples of mutagens include
radioactive substances, x-rays, ultraviolet radiation, and certain chemicals
.
Which of the following is an example of physical mutagens?
Physical mutagens include electromagnetic radiation, such as
gamma rays, X rays, and UV light
, and particle radiation, such as fast and thermal neutrons, beta and alpha particles. Mutagenic treatment of seeds is the most convenient and, therefore, the standard method in seed propagated crops.
