Biochemistry - Recombinant DNA Technology

Recombinant DNA

DNA formed by combining DNA from different sources.

Chimeric DNA

Hybrid combination of DNA from different organisms.

Main Purpose of Recombinant DNA

To identify genes/proteins and correct genetic defects.

Medical Use of Recombinant DNA

Produces hormones, vaccines, and other gene products.

Recombinant DNA

Isolation and manipulation of DNA to form recombinant molecules.

False

T/F: Recombinant DNA only involves human genes.

True

T/F: Recombinant DNA is also called chimeric DNA.

True

T/F: Recombinant DNA can predict disease risk.

False

T/F: This technology does not involve gene correction.

True

T/F: Recombinant DNA uses restriction enzymes.

Restriction Enzymes

DNA-cutting enzymes at specific palindromic sites.

Endonuclease

Cuts within the DNA strand.

Exonuclease

Cuts from the ends of DNA.

Vectors

Carriers like plasmids that transfer DNA into host cells.

DNA Library

Collection of cloned DNA fragments (genomic or cDNA).

True

T/F: Plasmids can replicate independently of the host cell.

False

T/F: Genomic libraries contain only exons.

False

T/F: Sticky ends are created by blunt-cutting enzymes.

True

T/F: A good vector must contain an origin of replication.

True

T/F: Restriction enzymes can recognize palindromic sequences.

PCR

In vitro technique to amplify DNA.

Sanger Sequencing

Uses dideoxynucleotides to terminate chain growth.

Southern Blot

Detects specific DNA sequences.

ASO Probes

Detect specific alleles in dot blots.

Microarray

Allows analysis of thousands of genes simultaneously.

True

T/F: Northern blotting detects RNA.

False

T/F: DNA probes are always long sequences.

True

T/F: RFLP is used in DNA fingerprinting.

True

T/F: RT-PCR uses RNA as the template.

False

T/F: Sanger sequencing reads from 3’ to 5’.

Familial

Inherited through gametes across generations.

Congenital

Present at birth, not always genetic.

Allele

Variant form of a gene.

Locus

Physical location of a gene on a chromosome.

Codominant

Both alleles expressed phenotypically.

False

T/F: All genetic diseases are congenital.

False

T/F: Dominant alleles require two copies for expression.

True

T/F: Recurrence risk refers to the chance a child inherits a disorder.

False

T/F: Heterozygotes have identical alleles.

False

T/F: Huntington’s is a congenital disorder.

X-Linked Inheritance

Traits associated with genes on the X chromosome.

No Male-to-Male Transmission

Characteristic of X-linked traits.

Hemophilia A

X-linked recessive disorder due to Factor VIII deficiency.

Duchenne Muscular Dystrophy

X-linked recessive disorder due to dystrophin gene mutation.

X-Linked Dominant

Affects males and females, but more common in females.

False

T/F: X-linked traits can be passed from father to son.

False

T/F: Hemophilia A is X-linked dominant.

True

T/F: Daughters of affected males are always carriers.

False

T/F: X-linked dominant traits appear more frequently in males.

True

T/F: Duchenne muscular dystrophy shows frameshift mutations.

Variable Expression

Different severity in individuals with the same genotype.

Incomplete Penetrance

Genotype present, but phenotype absent.

Delayed Onset

Disease manifests later in life (e.g., Huntington’s).

Pleiotropy

One gene affects multiple organs (e.g., Marfan Syndrome).

Anticipation

Earlier or more severe expression in succeeding generations.

False

T/F: Penetrance is the same as variable expression.

True

T/F: Marfan Syndrome shows pleiotropy.

True

T/F: Huntington’s disease exhibits anticipation.

False

T/F: Locus heterogeneity means different mutations in the same gene.

False

T/F: Prader-Willi syndrome is caused by maternal mutation.

Pedigree

Diagram of family history showing inherited traits.

Circle Symbol

Represents a female in pedigree

Square Symbol

Represents a male in pedigree

Diamond Symbol

Represents unknown sex in pedigree

Decision Tree

Determines inheritance type (autosomal vs. X-linked).

False

T/F: Male-to-male transmission suggests X-linkage.

True

T/F: Affected females more than males suggest X-linked dominant.

False

T/F: All mitochondrial traits are passed from the father.

True

T/F: A slash on a shape means the person is deceased.

True

T/F: Pedigree analysis can determine genotype.

Euploidy

Normal chromosome number in multiples of 23.

Aneuploidy

Abnormal number of chromosomes.

Trisomy 21

Down Syndrome (47, XX/XY +21).

Klinefelter Syndrome

47, XXY male with long legs, small testes.

Turner Syndrome

45, X with short stature, webbed neck.

False

T/F: Trisomy means there are two copies of a chromosome.

True

T/F: Turner syndrome is a monosomy.

False

T/F: Klinefelter syndrome occurs in females.

True

T/F: Aneuploidy results from nondisjunction.

True

T/F: Euploid cells may be triploid.