BIOC 3003 EXAM QUESTIONS WITH ANSWERS
100% SOLVED
what is the skg experiment? - ANSWER SKG is a mutation that triggers autoimmune
response resulting in gut inflammation (ileitis). However this must occur with curdlan
present (produced by microbiota) Therefore SPF conditions while still trigger ileitis
What is F. prausnitzii - ANSWER It stimulates anti inflammatory response, by creating
butyrate and NFkb(NFkb produces inflammatory cytokines) and promotes Treg cells(
regulatory T cells)r
What are the links between the gut microbiota and obesity, causality or consequence? -
ANSWER Transfer of fecal microbiota from an obese or lean twin to germ-free mice
leads to transference of that phenotype; co-housing mice leads to transfer of microbes
from lean to obese animals and reduces adiposity but only with a "low fat, high fibre"
diet. Transfer of an endotoxin-producing bacterium isolated from an obese individual to
a germ-free mouse model leads to obesity and insulin resistance; but only with a "high
fat" diet. Weight loss in the human donor resulted in a decrease in the relative
abundance of this bacterium.
how is GWAS conducted? - ANSWER Step 1 : measure the phenotype (disease or trait)
in a large number of people; Step 2 : collect DNA of each person and genotype using a
SNP chip assay (million SNP spread across the whole genome). Step 3 : use a
mathematical model to calculate the significance and the effect of each SNP Step 4 :
interpretation of results, the significant SNP point to relevant genes (and causative
mutations).
what is linkage disequilibrium - ANSWER Linkage disequilibrium (LD) is a term used in
genetics to describe the non-random association of alleles at two or more loci (gene
locations) on a chromosome. In other words, it is the tendency for certain alleles at
different loci to occur together more often than would be expected by chance.
how to investigate the effect of carrying an extra chromosome? - ANSWER RNA
sequencing.map gene expression differences related to chromosomal anomalies. The
experiment will require RNA samples from people with diverse numbers of
chromosomes
Puberty - ANSWER Higher BMI in girls linked to early puberty, loci for male and female
puberty discovered
Epigenetics of puberty - ANSWER inhibition of dna methylation does not result in
puberty
Disorders of puberty - ANSWER Central precocious puberty = early sexual development
, more common in girls. Early growth spurt: children with central precocious puberty may
be taller than their peers; however, they may stop growing abnormally early.
Genetic contribution to disease risk - ANSWER rare allele mutations such as BRAC1 P53
have a large effect size. low frequency variants have an intermediate effect and SNPs
which are common in complex traits
what is epigenetics? - ANSWER the changes in gene transcription through modulation of
chromatin not brought about by changes in dna sequence.
Four core proteins of histone - ANSWER H2A (Histone 2A)
H2B (Histone 2B)
H3 (Histone 3)
H4 (Histone 4)
risc complex - ANSWER The RNA-induced silencing complex (RISC) is a multi-protein
complex that plays a central role in the process of RNA interference (RNAi), which is a
crucial mechanism of gene regulation. RISC is involved in gene silencing through the
binding, unwinding, and guiding of small RNAs (such as siRNAs and miRNAs) to their
complementary target mRNAs, leading to mRNA degradation or translation inhibition.
histone variants? - ANSWER H3.3, H2AX, H2AZ
bivalent chromatin - ANSWER Bivalent domains are considered to be in a poised or
"primed" state, where genes are ready to be activated or repressed depending on
cellular signals. Activating Mark: Typically, the activating mark is histone H3 lysine 4
trimethylation (H3K4me3), which is associated with active transcription start sites.
Repressive Mark: The repressive mark is histone H3 lysine 27 trimethylation
(H3K27me3), which is associated with gene silencing.
imprinting - ANSWER Imprinting is an epigenetic phenomenon that results in the
differential expression of genes depending on whether they are inherited from the
mother or the father.
cis acting vs trans acting mechanism - ANSWER A cis-acting mechanism refers to a
regulatory process that acts on the same molecule of DNA or RNA where the gene of
interest is located. In other words, the regulatory elements and factors involved in a
cis-acting mechanism are located on the same DNA molecule (or RNA transcript) as the
gene they regulate. This is in contrast to trans-acting mechanisms, where regulatory
elements are located on separate molecules.
parental conflict theory - ANSWER Mother wants uniform distribution of nutrients for her
100% SOLVED
what is the skg experiment? - ANSWER SKG is a mutation that triggers autoimmune
response resulting in gut inflammation (ileitis). However this must occur with curdlan
present (produced by microbiota) Therefore SPF conditions while still trigger ileitis
What is F. prausnitzii - ANSWER It stimulates anti inflammatory response, by creating
butyrate and NFkb(NFkb produces inflammatory cytokines) and promotes Treg cells(
regulatory T cells)r
What are the links between the gut microbiota and obesity, causality or consequence? -
ANSWER Transfer of fecal microbiota from an obese or lean twin to germ-free mice
leads to transference of that phenotype; co-housing mice leads to transfer of microbes
from lean to obese animals and reduces adiposity but only with a "low fat, high fibre"
diet. Transfer of an endotoxin-producing bacterium isolated from an obese individual to
a germ-free mouse model leads to obesity and insulin resistance; but only with a "high
fat" diet. Weight loss in the human donor resulted in a decrease in the relative
abundance of this bacterium.
how is GWAS conducted? - ANSWER Step 1 : measure the phenotype (disease or trait)
in a large number of people; Step 2 : collect DNA of each person and genotype using a
SNP chip assay (million SNP spread across the whole genome). Step 3 : use a
mathematical model to calculate the significance and the effect of each SNP Step 4 :
interpretation of results, the significant SNP point to relevant genes (and causative
mutations).
what is linkage disequilibrium - ANSWER Linkage disequilibrium (LD) is a term used in
genetics to describe the non-random association of alleles at two or more loci (gene
locations) on a chromosome. In other words, it is the tendency for certain alleles at
different loci to occur together more often than would be expected by chance.
how to investigate the effect of carrying an extra chromosome? - ANSWER RNA
sequencing.map gene expression differences related to chromosomal anomalies. The
experiment will require RNA samples from people with diverse numbers of
chromosomes
Puberty - ANSWER Higher BMI in girls linked to early puberty, loci for male and female
puberty discovered
Epigenetics of puberty - ANSWER inhibition of dna methylation does not result in
puberty
Disorders of puberty - ANSWER Central precocious puberty = early sexual development
, more common in girls. Early growth spurt: children with central precocious puberty may
be taller than their peers; however, they may stop growing abnormally early.
Genetic contribution to disease risk - ANSWER rare allele mutations such as BRAC1 P53
have a large effect size. low frequency variants have an intermediate effect and SNPs
which are common in complex traits
what is epigenetics? - ANSWER the changes in gene transcription through modulation of
chromatin not brought about by changes in dna sequence.
Four core proteins of histone - ANSWER H2A (Histone 2A)
H2B (Histone 2B)
H3 (Histone 3)
H4 (Histone 4)
risc complex - ANSWER The RNA-induced silencing complex (RISC) is a multi-protein
complex that plays a central role in the process of RNA interference (RNAi), which is a
crucial mechanism of gene regulation. RISC is involved in gene silencing through the
binding, unwinding, and guiding of small RNAs (such as siRNAs and miRNAs) to their
complementary target mRNAs, leading to mRNA degradation or translation inhibition.
histone variants? - ANSWER H3.3, H2AX, H2AZ
bivalent chromatin - ANSWER Bivalent domains are considered to be in a poised or
"primed" state, where genes are ready to be activated or repressed depending on
cellular signals. Activating Mark: Typically, the activating mark is histone H3 lysine 4
trimethylation (H3K4me3), which is associated with active transcription start sites.
Repressive Mark: The repressive mark is histone H3 lysine 27 trimethylation
(H3K27me3), which is associated with gene silencing.
imprinting - ANSWER Imprinting is an epigenetic phenomenon that results in the
differential expression of genes depending on whether they are inherited from the
mother or the father.
cis acting vs trans acting mechanism - ANSWER A cis-acting mechanism refers to a
regulatory process that acts on the same molecule of DNA or RNA where the gene of
interest is located. In other words, the regulatory elements and factors involved in a
cis-acting mechanism are located on the same DNA molecule (or RNA transcript) as the
gene they regulate. This is in contrast to trans-acting mechanisms, where regulatory
elements are located on separate molecules.
parental conflict theory - ANSWER Mother wants uniform distribution of nutrients for her
