The mechanism of chromosome, gene mutation. The theory of mutation of Hugo De Vries презентация

The mechanism of chromosome, gene mutation. The theory of mutation of Hugo De Vries.

Слайд 2The mechanism of chromosome, gene mutation. The theory of mutation of Hugo

De Vries.



Слайд 3learning Objectives
to explain the mechanism of chromosome, gene mutation
study the theory

of mutation of Hugo De Vries and causes mutagenesis

Слайд 4Success criteria
1.Know and understand the essence of chromosome and gene

mutations.
2.Can explain emergence mechanism of chromosome and gene mutations.
3.Learners should describe correctly four types of mutation out of five.
4.Explain the theory of mutation of Hugo De Vries and causes mutagenesis.


Слайд 5Terminology
Mutation, gene mutation, chromosomal mutation, point mutation, deletion, addition, translocation,

aneuploidy, non-disjunction, polyploidy, mutagenesis, mutation causes, genotype mutation, inheritance, mutation variability, error, jump, death, new features, biochemical, physiological, morphological, sex and somatic mutation.

Слайд 6What is a Mutation?
Mutation is a change in the nucleotide sequence

of a gene or a chromosome.
In biology, a mutation is the permanent alteration of the nucleotide sequence of the genome of an organism, virus, or extra-chromosomal DNA or other genetic elements.
Mutations result from errors during DNA replication or other types of damage to DNA (such as may be caused by exposure to radiation or carcinogens).


Слайд 8Hugo De Veirs


Слайд 10The theory of mutation of Hugo De Vries.
1. Mutations or discontinuous

variations are the raw material of evolution.
2. Mutations appear all of a sudden. They become operational immediately.
3. Unlike Darwin’s continuous variations or fluctuations, mutations do not revolve around the mean or normal character of the species.
4. The same type of mutations can appear in a number of individuals of a species.
5. All mutations are inheritable.
6. Mutations appear in all conceivable directions.
7. Useful mutations are selected by nature. Lethal mutations are eliminated. However, useless and less harmful ones can persist in the progeny.
8. Accumulation of variations produce new species. Sometimes a new species is produced from a single mutation.
9. Evolution is a jerky and discontinuous process.

Слайд 11Points in Favour of the Mutation Theory
(1) Mutations are actually the

source of all variations and hence fountain head of evolution.
(2) Mutation theory can explain both progressive and retrogressive evolution.
(3) As the ratio of mutations is not the same in all individuals and their parts, mutation theory can explain the occurrence of both changed and unchanged forms.
(4) A number of mutations have appeared in the past.


Слайд 12Causes of mutagenesis
Spontaneous: random changes to base sequences of gene

(UV-light).
Induced: cause by factors – radiation, mutagenic chemicals, high temperature.

Mutagens: X-ray, radioactive isotopes, cosmic rays, UV-light and etc.

Слайд 13Types of mutation


Слайд 14Gene mutation
Change in the structure of a DNA molecule, producing a

different allele of a gene, is a gene mutation.
The DNA sequence of a gene can be altered in a number of ways. Gene mutations have varying effects on health, depending on where they occur and whether they alter the function of essential proteins.

Слайд 15The types of mutations include:
Gene mutation:
Point: Transition, Transversion, Mispairing
Frame – shift:

Deletion, Insertion

Missense mutation
Nonsense mutation

Слайд 16Point mutation (DNA)
Cause by base substitution


Слайд 17Frame – shift mutation (DNA)
caused by indels (insertions or deletions) of

a number of nucleotides in a DNA sequence that is not divisible by three.
can change the reading frame (the grouping of the codons), resulting in a completely different translation from the original.
the reading of the codons after the mutation to code for different amino acids.

Слайд 20Types of gene mutations.


Слайд 21Protein change mutation
Missense mutation
Nonsense mutation


Слайд 22Missense mutation
This type of mutation is a change in one DNA

base pair that results in the substitution of one amino acid for another in the protein made by a gene.

Слайд 23Nonsense mutation
A nonsense mutation is also a change in one DNA

base pair. Instead of substituting one amino acid for another, however, the altered DNA sequence prematurely signals the cell to stop building a protein. This type of mutation results in a shortened protein that may function improperly or not at all.

Слайд 24Insertion
An insertion changes the number of DNA bases in a gene

by adding a piece of DNA. As a result, the protein made by the gene may not function properly.

Слайд 25Deletion
A deletion changes the number of DNA bases by removing a

piece of DNA. Small deletions may remove one or a few base pairs within a gene, while larger deletions can remove an entire gene or several neighboring genes. The deleted DNA may alter the function of the resulting protein(s).

Слайд 26Duplication
A duplication consists of a piece of DNA that is abnormally

copied one or more times. This type of mutation may alter the function of the resulting protein.

Слайд 27Frameshift mutation
This type of mutation occurs when the addition or loss

of DNA bases changes a gene's reading frame. A reading frame consists of groups of 3 bases that each code for one amino acid. A frameshift mutation shifts the grouping of these bases and changes the code for amino acids. The resulting protein is usually nonfunctional. Insertions, deletions, and duplications can all be frameshift mutations.

Слайд 29Structural Chromosomal Mutations
This happens when homologous chromosomes paired
up, genes in chromosomes

broke apart, genes inserted in the wrong chromosome, or genes or set of genes are completely lost in the chromosome.
Basically, structural chromosomal mutations are classified into four:
deletion,
duplication,
inversion,
translocation (or shift places).

Слайд 31Deletion
This type of mutation occurs when a part of the

DNA is not duplicated or is lost during DNA replication. The size of this region can either be a mere nucleotide or can be large as an entire chromosome.



Слайд 32Duplication
This type of mutation occurs when an extra copy of

a region (or regions) in the DNA is produced. This duplicated region can either be located in its normal location in the chromosome or sometimes be located in other parts of the chromosomes or even in another chromosome.

Слайд 33Inversion
During inversion, a portion in the chromosome is reversed and

gets inserted back into the chromosome.
Basically, two types of inversion exist: pericentric and paracentric.

Слайд 34Translocation
Translocation happens when a fragmented chromosome tends to join with a

non-homologous chromosome. This newly-formed segment then detaches from the chromosome and moves to a new position on another chromosome.

Слайд 35Chromosomal Number Mutations
Aneuploidy:
Aneuploidy is a type of mutation in the chromosome

number wherein the ploidy (chromosome number) of the new individual is different from its wild type. This is typically a result of the nondisjunction of chromosomes during mitosis or meiosis, hence producing offspring with either extra or lost chromosomes.
Monosomic
Trisomic


2. Polyploidy
Polyploidy is a type of mutation that occurs when an individual bears more than one haploid set of chromosomes. If the individual with polyploidy bear three sets of haploid chromosomes, the condition is said to be triploidy whereas if it has four haploid sets, the condition is said to be tetraploidy.


Слайд 36
Interestingly, polyploidy is a common phenomenon among plants as well as

certain groups of fish, salamanders, frogs, and leeches.


Слайд 39Success criteria
1.Know and understand the essence of chromosome and gene

mutations.
2.Can explain emergence mechanism of chromosome and gene mutations.
3.Learners should describe correctly four types of mutation out of five.
4.Explain the theory of mutation of Hugo De Vries and causes mutagenesis.


Обратная связь

Если не удалось найти и скачать презентацию, Вы можете заказать его на нашем сайте. Мы постараемся найти нужный Вам материал и отправим по электронной почте. Не стесняйтесь обращаться к нам, если у вас возникли вопросы или пожелания:

Email: Нажмите что бы посмотреть 

Что такое ThePresentation.ru?

Это сайт презентаций, докладов, проектов, шаблонов в формате PowerPoint. Мы помогаем школьникам, студентам, учителям, преподавателям хранить и обмениваться учебными материалами с другими пользователями.


Для правообладателей

Яндекс.Метрика