LESSON_ MUTATION

Question 1

A permanent change of the nucleotide sequence of the genome of an organism, virus, or extra chromosomal DNA or other genetic elements. It results in damage to DNA that is not repaired or to
RNA genomes (typically caused by radiation or chemical mutagens), errors in the process of replication, or
from the insertion or deletion of segments of DNA by mobile genetic elements.

Answer 1

Mutation

Question 2

Is defined as an alteration in the sequence of nucleotides in DNA. This change can affect a single nucleotide pair or larger gene segments of a chromosome. Mutations cause changes in the genetic code that lead to genetic variation and the potential to develop the disease.

Can be generally categorized into two types: point mutations and base-pair insertions or deletions.

Answer 2

Gene Mutations

Question 3

Qre types of gene mutations, such as those affecting a small gene in one or a few nucleotides.

Answer 3

Small scale mutationa

Question 4

2 Types of Gene mutations

Answer 4

Point mutation and Frame- shift mutation

Question 5

is the change of a single nitrogen base in a DNA sequence.

It is usually the least harmful type of DNA mutation.

Codons are a sequence of three nitrogen bases in a row that are “read” by messenger RNA during transcription. That messenger RNA codon is then translated into an amino acid that goes on to make a protein that will be expressed by the organism.

Depending on the placement of a nitrogen base in the codon, a point mutation may have no effect on the protein.

Answer 5

Point Mutation

Question 6

Example of Point Mutation

Answer 6

Sickle cell anemia

Question 7

This happens when a point mutation causes a single nitrogen base in a codon for one amino acid in the protein glutamic acid to code for the amino acid valine instead. This single small change causes a normally round red blood cell to instead be sickled shaped

Answer 7

Sickle cell anemia

Question 8

There are three major types of point mutation which occurs by Substitution

Answer 8

Silent Mutation, Missense Mutation and Nonsense Mutation

Question 9

A type of substitution, or point, mutation, wherein the change in the DNA sequence of the gene has no effect on the amino acid sequence. For example, AAA (codes for the amino acid lysine, Lys) being mutated to AAG (which also codes for Lys).

Therefore, result in a deletion of an entire exon of the peptide sequence, the exon is not recognized because the splice site has been mutated. A synonymous mutation means a silent mutation that affects exon, without changing the protein sequence.

Answer 9

Silent Mutations

Question 10

A genetic alteration in which a single base pair substitution alters the genetic code in a way that produces an amino acid that is different from the usual amino acid at that position.

Answer 10

Missense Mutation

Question 11

A genetic alteration that causes the premature termination of a protein. The altered protein may be partially or completely inactivated, resulting in a change or loss of protein function. Also called nonsense variant.

Answer 11

Nonsense Mutation

Question 12

Are generally much more serious and often more deadly than point mutations.

Answer 12

Frame- Shift Mutation

Question 13

Add one or more extra nucleotides into the DNA. They are usually caused by transposable elements, or errors during the replication of repeating elements

Answer 13

Insertions

Question 14

Removing one or more nucleotides from the DNA. Like insertions, these mutations can alter the reading frame of the gene.

In general, they are irreversible: Though exactly the same sequence might, in theory, be restored by an insertion, transposable elements able to revert a very short deletion (say 1–2 bases) in any location either are highly unlikely to exist or do not exist at all.

Answer 14

Deletions

Question 15

Are long, stringy aggregates of genes that carry heredity information (DNA).

They are formed from chromatin, a mass of genetic material consisting of DNA that is tightly coiled around proteins called histones.

Are located in the nucleus of our cells and condense prior to the process of cell division. A non-duplicated chromosome is single-stranded and comprises a centromere region that connects two arm regions.

The short arm region is called the p arm and the long arm region is called the q arm.

Answer 15

Chromosome

Question 16

These changes are most often brought on by problems that occur during meiosis (division process of gametes) or
by mutagens (chemicals, radiation, etc.).

Unlike a gene mutation which alters a single gene or larger segment of DNA on a chromosome, chromosome mutations change and impact the entire chromosome.

Answer 16

Chromosomal mutation

Question 17

The joining of a fragmented chromosome to a non-homologous chromosome. The piece of chromosome detaches from one chromosome and moves to a new position on another chromosome.

Answer 17

Translocation Mutation

Question 18

This mutation results from the breakage of a chromosome in which the genetic material becomes lost
during cell division. The genetic material can break off from anywhere on the chromosome.

Answer 18

Deletion

Question 19

Are produced when extra copies of genes are generated on a chromosome.

Answer 19

Duplications

Question 20

The broken chromosome segment is reversed and inserted back into the
chromosome.

Answer 20

Inversion

Question 21

If the inversion encompasses the centromere of the chromosome,

Answer 21

Pericentric Inversion

Question 22

If it involves the long or short arm of the chromosome and does not include the centromere

Answer 22

Paracentric Inversion

Question 23

This type of chromosome is produced by the improper division of the centromere.

Contain either two short arms or two long arms.

A typical chromosome contains one short arm and one long arm.

Answer 23

Isochromosome Mutation

Question 24

A chromosome mutation that causes individuals to have an abnormal number of chromosomes

Answer 24

Aneuploidy

Question 25

Is the failure of homologous chromosomes to separate properly during cell division. It produces individuals with either extra or missing chromosomes.

Answer 25

Nondisjunction

Question 26

A chromosome mutation that results in individuals with more than one haploid set of chromosomes in a cell

Answer 26

Polyploidy

Question 27

Is a rare inherited disorder that causes progressive damage to the nervous system and most commonly affects infants.

It is mainly caused by the absence of a vital enzyme called
hexosaminidase-A (Hex-A). Symptoms usually appear between three to five months of age. The development slows down, and they gradually lose their ability to move.

Is a recessively inherited disease that only occurs when both parents carry a Tay-Sachs gene, and each parent transmits the
defective gene to their child. A child who inherits tthis genetic mutation (one from each parent) produces no functional Hex-A enzyme and is certain to develop this disease.

Located on chromosome 15.

Answer 27

Tay- Sachs Disease

Question 28

A genetic disease common among those who are from Africa. This genetic disease is the result of a point mutation where there is a change in just one nucleotide in the gene for
hemoglobin. The mutation causes the hemoglobin in red blood cells to transform to a sickle shape when de-oxygenated. Since the shape is altered, it cuts of blood circulation and clogs the capillaries.

Answer 28

Sickle cell anemia

Question 29

is a progressive, genetic disease that affects the secretory glands, including the mucus and sweat glands.

It causes persistent lung infections and limits the ability to breathe over time.

Answer 29

Cystic Fibrosis

Question 30

Is a rare inherited disorder that causes progressive damage to the nervous system and most commonly affects infants.

It is mainly caused by the absence of a vital enzyme called
hexosaminidase-A (Hex-A). Symptoms usually appear between three to five months of age. The development slows down, and they gradually lose their ability to move.

Is a recessively inherited disease that only occurs when both parents carry this gene, and each parent transmits the defective gene to their child. A child who inherits tthis genetic mutation (one from each parent) produces no functional Hex-A enzyme and is certain to develop this disease.

Located on chromosome 15.

Answer 30

Tay Sachs disease

Question 31

Is an inherited bleeding disorder that causes abnormal or exaggerated bleeding and poor blood clotting. It is also called a “royal disease” because it affected the royal families of
England, Germany, Russia and Spain in the 19th and 20th centuries.

Although it is passed down from parents to children, about 1/3 of cases are caused by a spontaneous mutation, a change in a gene. The most common type is hemophilia A.

Common symptoms include excessive bleeding and easy bruising.

Answer 31

Hemophilia

Question 32

Is the most common chromosomal disorder.

Have 47 chromosomes in their cells instead of 46 and suffer from mild to moderate disabilities.

Delayed development and behavioral problems are often
Common physical traits include a flat face, small head and short neck, and upward slanting eyes.

There are three main types: trisomy 21, mosaicism, and translocation.

Answer 32

Down Syndrome: Trisonomy 21, Mosaicism and Translocation

Question 33

Also known as XXY condition is a chromosomal condition that affects male physical and cognitive development.

The most common symptom is infertility. Some common symptoms include small penis, small firm testes, less pubic, armpit and facial hair, enlarged breasts, tall stature, and abnormal body proportions.

Answer 33

Klinefelter Syndrome

Question 34

Is a complex genetic disorder that affects growth, metabolism, appetite, cognitive function, behavioral problems, low levels of sex hormones and a constant feeling of hunger.

It is caused by the loss of genes in a specific region of chromosome 15. There is no cure for PWS, growth hormone, exercise, and dietary supervision can help build muscle mass and control weight.

Answer 34

Prader Willi Syndrome

Question 35

Is a rare chromosomal ailment that impacts girls. It is associated with the x chromosome that alters development in women, even though it isn’t normally inherited in families.

The most consistent functions of TS are brief stature and lack of ovarian development. Most women with this disease are infertile.

Answer 35

Turner Syndrome

Question 36

(also known as Trisomy 18 (T18) or Trisomy E) is a genetic disorder caused by the presence of all or part of an extra 18th chromosome.

The majority of people with the syndrome die
during the fetal stage; infants who survive experience serious defects and commonly live for short periods of time. I

s associated with a broad spectrum of abnormalities which consist of greater than one-hundred and thirty discrete defects involving the brain, heart, craniofacial structures, kidneys, and stomach.

Answer 36

Edward’s Syndrome

Question 37

Is a genetic condition present from birth that affects growth and development.

Infants with this condition often have a high-pitched cat-like cry, small head size, and a characteristic facial appearance. They may have trouble breathing and feeding difficulties. People with this condition typically have intellectual disability, developmental and speech delay, and behavioral issues.

Is due to a missing piece (deletion) of a specific part of chromosome 5 known as the ‘p’ arm. In general, the
severity of the symptoms is determined by the size and location of the deletion on chromosome 5.

Answer 37

Cri DU Chat

Question 38

Is a condition caused by a loss of genetic material from chromosome 11.

Because this deletion occurs at the end (terminus) of the long (q) arm of chromosome 11, Is also known as 11q terminal deletion disorder.

Answer 38

Jacobsen Syndrimome