Mutation Flashcards
refers to any change in the genetic material of the organism.
Mutation
categories of mutations (2)
Somatic mutation
Germ mutation
occurs in any body cell except egg cell; not passed on to offspring since it ceases to exist when the organism die.
Somatic mutation
occurs in the reproductive cell; can be transmitted to offspring and be passed on from one generation to another.
Germ mutation
Classification of Mutation (3)
a) Mutation due to changes in chromosome number
b) Mutation due to change in chromosome structure
c) Gene mutation
abberations in the chromosome may include: (3)
a) whole genome,
b) entire single chromosome, and
c) part of the chromosome.
Mutation that results from changes in chromosome number can be expressed in the form of __ or __
euploidy or aneuploidy
are characterized by the possession of an entire set of chromosome
Euploids
have an imbalance in the sex determining mechanism resulting to sterility due to aberrant meiosis.
polyploids/y
is a characteristic more common in plants than in animals
Polyploidy
are characterized by the multiplication of a single whole genome or
chromosome set.
Autopolyploids
Polyploid plants are characterized by (3);
- Increased in the individual cell size.
- Slower growth rate and later maturity than diploids
- Thicker leaves, larger but fewer flowers, and larger fruits than diploids, reduce fertility in varying degrees.
are characterized by the multiplication of two or more genomes or
chromosome sets.
Allopolyploids
They are responsible for the formation of the new species such as wheat, tobacco, and Raphanobrassica
Allopolyploids
occurs when one or more chromosomes of a normal set (genome) are
lacking or are present in excess.
Aneuploidy
Examples of aneuploidy in man: (7)
-Trisomy 21 (Down Syndrome)
-Trisomy 18 (Edward Syndrome)
-Trisomy 13 (Patau Syndrome)
-Turner’s Syndrome (2n = 45, 22II +X)
-Klienfelter’s Syndrome (2n = 47, 22II +XXY)
-Metafemale
-Double Y Syndrome.
They are characterized by mental retardation and premature menopause
metafemale
They are characterized by antisocialism, aggressiveness, criminal tendency, and low IQ
Double Y Syndrome
Types of Structural Changes in the Chromosome (4)
- Deficiencies or Deletions
- Duplication or Repeats
- Inversion
- Interchange or Reciprocal Translocation
represent a loss of segment of the chromosome
Deficiencies or Deletions
Examples of chromosomal deficiency in man: (2)
Philadelphia 22 chromosome
Cri-du-chat Syndrome
is a deficiency for the large portion of long arm of chromosome 22
Philadelphia 22 chromosome
is due to the deletion in the short arm of the chromosome 5.
It is distinguished by cat-like cry during infancy, unique facial feature and other form of physical and mental retardation
Cri-du-chat Syndrome
occur when the section of the chromosome is in excess of the
normal amount.
2Duplication or Repeats
due to the rotation of chromosome segment to a full 180 degree
- Inversion
Inversion can be classified as (2)
-paracentric inversion
-Pericentric inversion
occurs when the centromere is not included in the inverted segment
paracentric inversion
occurs when the inverted segment includes the centromere.
Pericentric inversion
occurs when the single break in two nonhomologous chromosomes produce an exchange sections between them.
Interchange or Reciprocal Translocation
involves a change in the nucleotide
Gene mutation or point mutation
two categories of gene mutation
-Base pair substitution
-Frameshift mutation
due to copy errors during DNA replication
Base pair substitution
two types of base pair substitution
Transition mutation
Transversion mutation
is due to the substitution purine with another purine or the substitution of one pyrimidine with another pyrimidine
Transition mutation
refers to the substitution of purine with pyrimidine or substitution of pyrimidine with purine.
Transversion mutation
three kinds of amino acid substitution:
-Non-sense mutation
-Missense mutation
-Same sense mutation
refers to a base pair substitution that results to the formation of a termination or non-sense codon.
Non-sense mutation
refers to a base pair substitution that results to the substitution of an amino acid in the polypeptide chain.
Missense mutation
refers to a base pair substitution that does not change the type of amino acid in the polypeptide chain
Same sense mutation
an insertion or deletion of a base that changes the reading frame of the entire subsequent sequence.
Frameshift mutation
Anything that can cause or induce mutation is known as
mutagenic agents
Types of mutagenic agents (3)
Physical mutagen
Chemical mutagen
Environmental mutagen
2 types of physical mutagen
-Ionizing radiation (X-ray, gamma ray, etc.)
-Non-ionizing radiation (UV rays)
can break the DNA strand (produce break in the chromosome rather
than a base change).
It can effectively killed viruses with single stranded DNA.
Ionizing radiation
can impart enough energy causing mutation; does not penetrate deeply into the tissues; effective in killing bacteria and fungus; may cause skin cancer
Non-ionizing radiation
Chemical mutagen (7)
-Nitrous acid
-Base analogues
-Proflavin and other dyes
-Colchicines
-Mustard gas (Sulfur mustard)
-Marijuana
-Hair dye components
Changes C to Uracil Changes CG pair to TA pair
Nitrous acid
Substitute for DNA bases
Base analogues
Inhibits spindle formation and prevents anaphase
Proflavin and other dyes
Blocks mitotic cells in metaphase
Colchicines
leads to cross-link formation, inhibition of DNA synthesis and repair, point mutations, and induction of chromosometype and chromatid-type aberrations
Mustard gas (Sulfur mustard)
component of marijuana
delta – 9 – THC or delta-9-tetrahydrocannabinol
Mutagenic in bacteria; Malignant transformation in mammalian cells; Mutation in Drosophila; mitotic recombination in yeast; tumors in rodents
Hair dye components
Mutagenic chemicals and their carcinogens (4)
-Air and water pollutants/benzo – a – pyrene
-Food additives/hydrocarbon
-Food preservatives/aflatoxin
-Agricultural chemicals/components of commercially available dyes
2 ways to screen chemicals for mutagenicity
Host – mediated Assay
Ames Test
- Inject the indicator microorganisms into the mouse.
- Expose the mouse to chemicals being tested.
- Reinsulate the indicator microorganisms from the mouse.
- Place on minimal medium and score for reversions.
Host – mediated Assay
- Homogenate the mammalian liver.
- Add the indicator microorganisms into the homogenate.
- Expose them to chemicals being tested.
- Reisolate the indicator microorganisms from the homogenate. 5. Place on a minimal medium and score for reversions.
Ames Test
__ percent of the tested carcinogens are shown to be mutagenic.
70%
biblical times=___
middle ages=___
last century=___
modern ages=___
biblical times=leprosy
middle ages= bubonic plague
last century= tuberculosis
modern ages= cancer
common term for aggressive and usually fatal form of a large class of
disease known as neoplasm
Cancer
a condition by which the biological mechanisms that govern the growth and metabolism of a normal cell and the overall interactions of living organisms are not followed
Neoplasm
Classification of neoplasm: 2
-Benign neoplasm
-Malignant neoplasm
-encapsulated; structure is similar to the tissue; do not metastasize
Benign neoplasm
not encapsulated; abnormal and unstructured appearance; Grow rapidly; metastasize
Malignant neoplasm
a term referring to cancer –causing agent
Carcinogen
categories of carinogens (3)
physical agent
chemical agent
biological agent
Examples of chemical agents that can cause cancer. (5)
-Hydrocarbons and nitrosamines
-Aromatic amines-
-Drugs for cancer treatment
-Hormones
-aflatoxin
components of cigarette smokes
Hydrocarbons and nitrosamines
component in dye making
Aromatic amines (2
– naphtylamine
Break the DNA strands of cancer cells, thus killing the cell. However, they might also induce cancer in normal cells
Drugs for cancer treatment
female hormone that is being administrated in menopausal women may result in cancer of the uterus
Estrogen
molecule produced by the strains of mold Aspergillus causing liver cancer
aflatoxin
this category of carcinogen include ultraviolet and high-energy
radiation
Physical agents
Cancer caused by radiation (6)
leukemia
thyroid
breast
stomach
uterus
bone cancer
2 biological agents
- blood flukes
- Epstein barr viruses, Papilloma virus and Herpes virus
causing shistosomiasis may also cause bladder cancer
Blood flukes
cause cancer of the nose and throat
Epstein barr viruses, Papilloma virus and Herpes virus
Seven Warning Signals of Cancer (7)
- Change in bowel or bladder functions.
- A sore that does not heal
- Unusual bleeding or discharge
- Thickening or lump in the breast or elsewhere
- Indigestion or difficulty in swallowing
- A change in wart or mole
- Nagging cough or hoarseness
Common Types of Cancers (4)
Breast cancer
Lung Cancer
Skin cancer
prostate cancer
(successful in detecting tumors at early stage
mammography
breast cancer can be treated by __ or __, followed by chemotherapy
mastectomy, lumpectomy
Principally caused by tobacco smoking.
Lung Cancer
increases dramatically with age; about 80% diagnose in men over 65 years of age
Prostate cancer
caused by excessive exposure to sunlight
Skin Cancer
