BIO 305 UPDATED REVIEW TIPS QUESTIONS AND
ANSWERS SURE A+
✔✔nurturing causes - ✔✔methyl groups to be removed from the glucocorticoid receptor
(GR) gene
✔✔Glucocorticoid Receptor (GR) - ✔✔-detects levels of cortisol
-too much can lead to heart disease, depression, and high risks of infections
✔✔why is control of gene expression necessary? - ✔✔Transcription and translation
must be controlled so that the appropriate amounts of proteins are present for specific
cell types.
✔✔Define epigenetics - ✔✔the study of environmental influences on gene expression
that occur without a DNA change
✔✔how do histones control gene expression, yet genes also control histones? -
✔✔Histones control which genes are transcribed based on acetyl, methyl and
phosphate binding.1. Acetyl binding neutralizes the histone's negative charge. As
histones becomes more positive DNA is repelled by it. This exposes the DNA to TF 2.
Methyl groups attract a protein that blocks transcription. It also can bind directly to
cytosine and turn off transcription
, ✔✔Explain how a mutation in a promoter can affect gene expression - ✔✔A promoter
mutation can affect the ease of transcription for that gene. It may cause the gene to be
overexpressed or silenced which would affect protein expression?
✔✔What controls whether histones enable DNA wrapped around them to be
transcribed? - ✔✔Acetylation, methylation and phosphorylation
✔✔Name a mechanism that silences transcription of a gene and a mechanism that
blocks translation of an mRNA - ✔✔Methylation silences transcription of a
genemicroRNAs blocks translation of mRNA
✔✔How can alternate splicing generate more than one type of protein from the
information in a gene? - ✔✔Pre-mRNA transcripts that contain introns and exons are
processed to produce mature mRNA in a specific cell type. By regulating which exons
are retained and spliced, exon shuffling generates more than one mature mRNA and
therefore different proteins.
✔✔In the 1960s a gene was defined as a continuous sequence of DNA, located
permanent at one place on a chromosome, that specifies a sequence of AA from one
strand. List 3 ways that definition has changed. - ✔✔1. Discontinuous
2. Transposons
3. Alternate splicing
✔✔acetyl removed - ✔✔turns it off
✔✔ Transcription steps - ✔✔DNA to RNA 1. TATA box recognized 2. Transcription
factor opens DNA 3. RNA polymerase adds nucleotides to growing mRNA 4. Stop
sequence reached 5. Cap added to 5' end 6. Tail added to 3' end 7. introns removed 8.
Exons spliced together 9. mRNA exits nucleous
✔✔Proteins are composed of - ✔✔Amino Acids
used for: structures, movement, transport, chemical reactions
✔✔list four ways that DNA can mutate without affecting the phenotype - ✔✔1. Silent
mutation: is a change in the sequence of nucleotide bases which constitutes DNA,
without a subsequent change in the amino acid or the function of the overall protein.
2. Synonymous mutation (also a silent mutation)
3. A DNA mutation in a coding region that does change the amino acid, but the resulting
protein is still functional because the new amino acid is similar to the original one.
4. A DNA mutation in a coding region that changes the amino acid to a stop or a very
different amino acid, leading to the formation of a very differently folded or shortened
protein - but this protein is not super important in the cell, and the cell appears to still be
ANSWERS SURE A+
✔✔nurturing causes - ✔✔methyl groups to be removed from the glucocorticoid receptor
(GR) gene
✔✔Glucocorticoid Receptor (GR) - ✔✔-detects levels of cortisol
-too much can lead to heart disease, depression, and high risks of infections
✔✔why is control of gene expression necessary? - ✔✔Transcription and translation
must be controlled so that the appropriate amounts of proteins are present for specific
cell types.
✔✔Define epigenetics - ✔✔the study of environmental influences on gene expression
that occur without a DNA change
✔✔how do histones control gene expression, yet genes also control histones? -
✔✔Histones control which genes are transcribed based on acetyl, methyl and
phosphate binding.1. Acetyl binding neutralizes the histone's negative charge. As
histones becomes more positive DNA is repelled by it. This exposes the DNA to TF 2.
Methyl groups attract a protein that blocks transcription. It also can bind directly to
cytosine and turn off transcription
, ✔✔Explain how a mutation in a promoter can affect gene expression - ✔✔A promoter
mutation can affect the ease of transcription for that gene. It may cause the gene to be
overexpressed or silenced which would affect protein expression?
✔✔What controls whether histones enable DNA wrapped around them to be
transcribed? - ✔✔Acetylation, methylation and phosphorylation
✔✔Name a mechanism that silences transcription of a gene and a mechanism that
blocks translation of an mRNA - ✔✔Methylation silences transcription of a
genemicroRNAs blocks translation of mRNA
✔✔How can alternate splicing generate more than one type of protein from the
information in a gene? - ✔✔Pre-mRNA transcripts that contain introns and exons are
processed to produce mature mRNA in a specific cell type. By regulating which exons
are retained and spliced, exon shuffling generates more than one mature mRNA and
therefore different proteins.
✔✔In the 1960s a gene was defined as a continuous sequence of DNA, located
permanent at one place on a chromosome, that specifies a sequence of AA from one
strand. List 3 ways that definition has changed. - ✔✔1. Discontinuous
2. Transposons
3. Alternate splicing
✔✔acetyl removed - ✔✔turns it off
✔✔ Transcription steps - ✔✔DNA to RNA 1. TATA box recognized 2. Transcription
factor opens DNA 3. RNA polymerase adds nucleotides to growing mRNA 4. Stop
sequence reached 5. Cap added to 5' end 6. Tail added to 3' end 7. introns removed 8.
Exons spliced together 9. mRNA exits nucleous
✔✔Proteins are composed of - ✔✔Amino Acids
used for: structures, movement, transport, chemical reactions
✔✔list four ways that DNA can mutate without affecting the phenotype - ✔✔1. Silent
mutation: is a change in the sequence of nucleotide bases which constitutes DNA,
without a subsequent change in the amino acid or the function of the overall protein.
2. Synonymous mutation (also a silent mutation)
3. A DNA mutation in a coding region that does change the amino acid, but the resulting
protein is still functional because the new amino acid is similar to the original one.
4. A DNA mutation in a coding region that changes the amino acid to a stop or a very
different amino acid, leading to the formation of a very differently folded or shortened
protein - but this protein is not super important in the cell, and the cell appears to still be
