Midterm Study Guide- 6233 Test
Questions 2025\2026 With Actual
Detailed Solutions.
The central dogma of molecular biology - Answer transcription and translation
How many genes in the human genome? - Answer ~25,000 genes
How many hydrogen bonds between Adenine & Thymine? - Answer 2
How many hydrogen bonds between Cytosine & Guanine? - Answer 3
What is a promotor? - Answer nucleotide sequence that lies just upstream of a gene. RNA
polymerase II binds to a promotor site on DNA to initiate transcription. Plays an important role
in initiating gene expression.
What is an exon? - Answer Sections that contain the mRNA that specifies proteins.
What is an intron? - Answer The excised sequences of a gene removed by nuclear enzymes to
form function mRNA.
What is the transcriptional start site in a gene? - Answer Transcription is initiated at the
transcriptional "start" site in the 5'-UTR region..
How are DNA codons associated with the essential amino acids? - Answer Each codon (3
bases) encodes for an amino acid. DNA -> (transcription) -> mRNA -> (translation) -> coded for
proteins.
Genotype - Answer the genetic makeup of an organism
Actual version of the gene you have
Phenotype - Answer The set of observable characteristics of an organism (resulting from
,Allele - Answer Alternative or variable form of gene at specific chromosome.
Homozygous - Answer Individual with two identical alleles at a DNA locus
Heterozygous - Answer Individual with two different alleles at a DNA locus
ex: Bb
Dominant allele - Answer Allele expressed in the same way as a single copy (heterozygous)
and double copy (homozygote)
This is the allele that will express itself in a heterozygous combination
Recessive allele - Answer Allele phenotypically expressed only in the homozygous state
In genetics, a trait that must be contributed by both parents in order to appear in the offspring.
These traits can be carried in a person's genes without appearing in that person.
Allelic heterogeneity - Answer In this situation different alleles at the same locus cause the
same disorder. A notable example is cystic fibrosis, where more than 600 different alleles can
cause the associated symptoms.
Variable expressivity - Answer The range or intensity of the trait in question. The severity of
symptoms can vary from person to person, for example, in single-gene disorders such as cystic
fibrosis and sickle cell disease and in common, complex disorders such as major depression and
diabetes.
This refers to the degree to which a condition or disorder is expressed in an individual.
Locus heterogeneity - Answer a single disorder, trait, or pattern of traits caused by mutations
in genes at different choromosomal loci
Reduced penetrance - Answer when those who have the appropriate genotype fail to express
the disease, though they may pass the disease gene to the next generation
, Delayed age of onset - Answer also called "age-dependent penetrance"- diseases that do not
present until after patients reach reproductive age or adulthood. not possible until later in life to
determine whether an individual carries a mutation
Pleiotropy - Answer genes that have effects on multiple aspects of physiology or anatomy
One gene winds up controlling multiple phenotypic traits in the organism. Causes inherited
diseases and disorders.
Examples of pleiotropic genes in diseases - Answer Marfan syndrome, cystic fibrosis,
osteogenesis imperfecta, sickle cell anemia
Genomic imprinting - Answer the process in which genetic material is expressed differently
when inherited from the mother than when inherited from the father
Autosomal dominant inheritance - Answer females and males exhibit trait in equal
proportions
no skipping of generations- present in every generation
probability of inheriting disease from Aa and aa parents is 50%
on average, half the children will express the disease and half will not
father to son transmission may be observed
*If every single generation has someone affected, it's autosomal dominant*
Common autosomal dominant disorders - Answer Breast cancer genes BRCA 1 and BRCA2
Neurofibromatosis
Marfan syndrome
Familial hypercholesterolemia
Autosomal dominant polycystic kidney disease
achondroplasia
Huntington's disease
Autosomal recessive inheritance - Answer faily rare in populations
Questions 2025\2026 With Actual
Detailed Solutions.
The central dogma of molecular biology - Answer transcription and translation
How many genes in the human genome? - Answer ~25,000 genes
How many hydrogen bonds between Adenine & Thymine? - Answer 2
How many hydrogen bonds between Cytosine & Guanine? - Answer 3
What is a promotor? - Answer nucleotide sequence that lies just upstream of a gene. RNA
polymerase II binds to a promotor site on DNA to initiate transcription. Plays an important role
in initiating gene expression.
What is an exon? - Answer Sections that contain the mRNA that specifies proteins.
What is an intron? - Answer The excised sequences of a gene removed by nuclear enzymes to
form function mRNA.
What is the transcriptional start site in a gene? - Answer Transcription is initiated at the
transcriptional "start" site in the 5'-UTR region..
How are DNA codons associated with the essential amino acids? - Answer Each codon (3
bases) encodes for an amino acid. DNA -> (transcription) -> mRNA -> (translation) -> coded for
proteins.
Genotype - Answer the genetic makeup of an organism
Actual version of the gene you have
Phenotype - Answer The set of observable characteristics of an organism (resulting from
,Allele - Answer Alternative or variable form of gene at specific chromosome.
Homozygous - Answer Individual with two identical alleles at a DNA locus
Heterozygous - Answer Individual with two different alleles at a DNA locus
ex: Bb
Dominant allele - Answer Allele expressed in the same way as a single copy (heterozygous)
and double copy (homozygote)
This is the allele that will express itself in a heterozygous combination
Recessive allele - Answer Allele phenotypically expressed only in the homozygous state
In genetics, a trait that must be contributed by both parents in order to appear in the offspring.
These traits can be carried in a person's genes without appearing in that person.
Allelic heterogeneity - Answer In this situation different alleles at the same locus cause the
same disorder. A notable example is cystic fibrosis, where more than 600 different alleles can
cause the associated symptoms.
Variable expressivity - Answer The range or intensity of the trait in question. The severity of
symptoms can vary from person to person, for example, in single-gene disorders such as cystic
fibrosis and sickle cell disease and in common, complex disorders such as major depression and
diabetes.
This refers to the degree to which a condition or disorder is expressed in an individual.
Locus heterogeneity - Answer a single disorder, trait, or pattern of traits caused by mutations
in genes at different choromosomal loci
Reduced penetrance - Answer when those who have the appropriate genotype fail to express
the disease, though they may pass the disease gene to the next generation
, Delayed age of onset - Answer also called "age-dependent penetrance"- diseases that do not
present until after patients reach reproductive age or adulthood. not possible until later in life to
determine whether an individual carries a mutation
Pleiotropy - Answer genes that have effects on multiple aspects of physiology or anatomy
One gene winds up controlling multiple phenotypic traits in the organism. Causes inherited
diseases and disorders.
Examples of pleiotropic genes in diseases - Answer Marfan syndrome, cystic fibrosis,
osteogenesis imperfecta, sickle cell anemia
Genomic imprinting - Answer the process in which genetic material is expressed differently
when inherited from the mother than when inherited from the father
Autosomal dominant inheritance - Answer females and males exhibit trait in equal
proportions
no skipping of generations- present in every generation
probability of inheriting disease from Aa and aa parents is 50%
on average, half the children will express the disease and half will not
father to son transmission may be observed
*If every single generation has someone affected, it's autosomal dominant*
Common autosomal dominant disorders - Answer Breast cancer genes BRCA 1 and BRCA2
Neurofibromatosis
Marfan syndrome
Familial hypercholesterolemia
Autosomal dominant polycystic kidney disease
achondroplasia
Huntington's disease
Autosomal recessive inheritance - Answer faily rare in populations
