genetics quiz Flashcards
Relationship between genes and enzymes was first suggested by an English physician, in 1902.
Archibald Garrod
This concept was developed as a result of his study on a disease called
alkaptonuria
is a recessive trait that causes arthritis. The urine of the affected person
turns black upon exposure to the air.
Alkaptonuria
is the one controlling the synthesis of protein through the RNA. This relationship constitutes to what we called the central dogma of molecular biology, which shows the flow of information in the biological systems (Figure 6.3)
DNA
refers to the transfer of genetic information from the nucleotide sequence of the DNA to the nucleotide sequence of the RNA.
Transcription
Types of ribonucleic acid (RNA) (3)
Messenger RNA or mRNA
Transfer RNA or tRNA
Ribosomal RNA or rRNA
carry the instruction for protein synthesis from the DNA (nucleus) to the ribosomes (cytoplasm)
Messenger RNA or mRNA
brings the activated amino acids to the mRNA.
Transfer RNA or tRNA
incorporated in the ribosomes
Ribosomal RNA or rRNA
Transcription consists of three events (3)
initiation
elongation
termination
refers to the synthesis of a polypeptide chain using the genetic instructions from the mRNA.
Translation
Features of Genetic Code (5)
Genetic Code is triplet.
Genetic Code is degenerate/redundant/repetitious
Genetic Code is non-overlapping
Genetic Code is universal
There are three nonsense codons
blank, blank and blank are called terminator or non-sense codons since they terminate the
amino acid chain in the synthesis protein.
UAG, UAA, and UGA
In 1941, blank and blank formulated the One Gene-One Enzyme Hypothesis.
Beadle and Tatum
RNA polymerase binds to a sequence of DNA called the
promoter
acts as a template for RNA polymerase.
template strand
refers to any change in the genetic material of the organism. It may result
from a change in the base sequence of the DNA in the chromosome.
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
Euploids are characterized by the possession of an entire set of chromosome (4)
Haploid
Diploid
Triploid
Polyploids
carry only one genome
Haploid
carry 2 genomes.
Diploid
carry 3 genomes
Triploid
carry 3 or complete set of chromosomes.
Polyploids
are characterized by the multiplication of a single whole genome or
chromosome set.
Autopolyploids
being are quite rare. These cases result to
a) Spontaneous aborted fetus
b) Stillborn
c) Some live for an hour but gross malformations.
Polyploidy in human
occurs when one or more chromosomes of a normal set (genome) are
lacking or are present in excess. So, they have incomplete genome.
Aneuploidy
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
occur when the section of the chromosome is in excess of the normal amount.
Duplication or Repeats
is due to the rotation of chromosome segment to a full 180 degree.
Inversion
occurs when the single break in two nonhomologous chromosomes produce an exchange sections between them.
Interchange or Reciprocal Translocation
point mutation involves a change in the nucleotide.
Gene Mutation
There are two
categories of gene mutation (2)
base pair substitution
frameshift mutation
due to copy errors during DNA replication. There are two types of base pair substitution; the transversion mutation and the transition mutation.
Base pair substitution
is due to the substitution purine with another purine or the substitution of one pyrimidine with another pyrimidine
Transition mutation
on the other hand, refers to the substitution of purine with pyrimidine or substitution of pyrimidine with purine.
Transversion 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
Inject the indicator microorganisms into the mouse
Host – mediated Assay
Homogenate the mammalian liver.
Ames Test
Classification of neoplasm: (2)
Benign neoplasm
Malignant neoplasm
its structure is similar to the tissue from where they were derived
Benign neoplasm
has an abnormal and unstructured appearance with abnormalities in chromosomes
structure
Malignant neoplasm
Common Types of Cancers (4)
Breast cancer
Lung Cancer
Prostate cancer
Skin Cancer
leading killer of women worldwide
Breast cancer
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
