X, Y and microbiome Flashcards
What does hemizygous mean?
a normally diploid individual has only one copy of a gene; genes on X in males; genes on X for XO females
The X chromosome does not have any genes.
false, the X chromosome is very large and has 800-900 genes
What is likely origin of DNA found in mitochondria?
bacteria that colonized primordial cells
What is a function of mitochondria in the cell?
generate energy in the form of ATP
Why do we refer to the inheritance of mitochondrial DNA as having “Tail-Female” inheritance?
mitochondria are almost always inherited from the egg
What is associate with the number of mitochondria in a cell?
cells with high metabolic activity have more mitochondria than cells with low activity
When a research result is statistically significant, what does that mean?
the result is repeatable
Which of the following is true about the mitochondria genome?
is is small, having only 16,500 bp compared to 2.5 billion bp on chromosomes
What is true about the genes for function of mitochondria?
most of the genes for mitochondria function are actually on chromosomes
Why do we think that mitochondria are descended from primordial prokaryotes (bacteria)?
their DNA sequence is more similar to that of prokaryotes than of autosomes, mitochondria have codons like bacteria and not like vertebrate codons, the mitochondria genome is circular like bacteria
What is the name of the theory that prokaryotes were the origin of mitochondria?
endosymbiotic theory
Why is the mitochondrial DNA a good tool for a molecular clock?
mitochondria DNA polymerase is error prone
What conclusions followed the comparison of mitochondria haplotypes of horses from around the world?
many mares were part of the foundation of domestic horses
The X and Y chromosome have very clear differences. Why do the X and Y chromosome pair during meiosis?
they share a small set of genes in the pseudo autosomal region
Why do we think the Y chromosome evolved from the X chromosome?
when the PAR is longer in some species, the genes found are X chromosome genes
Why do we think a large number of stallions contributed to the foundation of the domestic horse?
we see a large number of Y chromosome haplotypes in ancient DNA
Why do we think that most modern horse breeds have a single Y chromosome haplotype?
breeders choose stallions from the Mediterranean region between 700 and 1200 years ago
Where is the microbiome found?
throughout the body
What is the difference between pathogenic bacteria and commensal bacteria?
commensal bacteria do not cause disease while pathogenic bacteria do
There is more variation between individuals in their microbiome than in their genome.
true; the genome is 99% similar among individuals of a species, the microbiome changes depending on life history, our microbiome only 10% similar
What is the ration of microbiome cells to genome cells? roughly
3:1; microbiome cells outnumber animal cells
What is the mass (weight) of the microbiome?
about 6 pounds
The microbiome contributes gene functions and substances not found or produced by the horse or human genome.
true
What is the limit on discovery for early investigations (up to 1970) of the microbiome?
ability to grow the microbes in the laboratory
How did DNA sequencing make it possible to advance microbiome studies?
DNA sequences were found that were for microbiomes we had not been able to culture
What was the initial basis for identifying microbes as belonging to species never seen before? or identifying with species they did belong to?
sequence of 61s Ribosomal DNA sequence
What influences the type of microbe found in a location?
vaginal vs cesarean birth, diet, age, genome
What are biofilms?
a community of microbes that interact in a commensal fashion
What is the most common site for study of the microbiome?
fecal material
What is a molecular clock used for?
identify time since common ancestor
What is PAR?
pseudo autosomal region; the basis for pairing of Y and X during meiosis
What helped with identifying presence of microbes?
DNA sequencing made it possible to identify presence of microbes whether or not they could be grown in the lab
