ESSENTIAL CELL BIOLOGY EXAM
QUESTIONS WITH COMPLETE
SOLUTIONS
Define organotrophic - ANSWER-Organisms that feed on other living things or the
organic chemicals they produce
Define phototrophic - ANSWER-Organisms that derive energy from non-living world.
They feed on the sun
Define lithotrophic - ANSWER-Organisms that derive energy directly from nonliving
world. They feed on rocks.
CO2 and N2 are extremely unreactive. True or False? - ANSWER-True
Which atoms are plentiful in nonliving environments? - ANSWER-H, C, N, O, S, P
What is an example of nitrogen fixing bacteria? - ANSWER-Nodules on roots
Which domain of life exhibits the greatest biochemical diversity? - ANSWER-
Prokaryotes
DNA storage of prokaryotes vs eukaryotes - ANSWER-Prokaryotes: DNA is in no
distinct nuclear compartment. Ex. Bacteria, Archaea
Eukaryotes: DNA in membrane bounded nucleus: plants, animals, fungi
Define conservation in terms of genes - ANSWER-Some genes evolve rapidly, others
are highly conserved (slower). A series of mutation events and natural selection
determine how organisms evolve. Ex: rRNA is highly conserved
Most bacteria and archaea have 1000-6000 genes. Why? - ANSWER-Natural selection
favors cells that can reproduce quickly. They maintain a good size to surface area ratio
to maximize uptake of nutrients.
True of False: New genes are generated from pre-existing genes - ANSWER-True
How do viruses work? - ANSWER-They serve as vectors that transfer genetic material.
True or False: Sex is a form of horizontal gene transfer - ANSWER-True
True of False: The function of a gene can often be deduced from its sequence -
ANSWER-True
, How many gene families are common to the three primary branches of life? - ANSWER-
More than 200 gene families
What was one of the spotlights of Molecular Biology? - ANSWER-E.coli
Where are the genomes in eukaryotes? - ANSWER-In chloroplasts and mitochondria -
they are considered to be hybrid genomes. They are degenerate, cut down versions of
original genomes.
How many nucleotides and coded proteins does the mitochondria have in eukaryotic
cells? - ANSWER-16k nucleotides, codes for 13 proteins, 2 rRNAs and 22tRNAs. Many
of the original genes moved into the nucleus
What type of DNA are eukaryotic genomes rich in? - ANSWER-Regulatory DNA
What defines the program of multicellular development in eukaryotes? - ANSWER-The
genome
What is transcriptome? - ANSWER-All transcribed RNA
What is Deep RNA sequencing? - ANSWER-Sequencing the entire RNA repertoire of
RNA from a cell
Why do we use model organisms? - ANSWER-Because we can't sequence all
organisms at once. Need to concentrate efforts and pick a convenient model to focus
research.
What is the model eukaryote? Why? - ANSWER-Yeast: saccharamyces cerevisiae.
Closely related to both animals and plants, has a small genome, and divides indefinitely
in haploid or diploid state.
What is the model plant? - ANSWER-Arabidopsis - Thale Cress (related to mustard).
Grown easily indoors, small thallus and a short generation time of 8 weeks.
What is the world of animal cells represented by? - ANSWER-A worm, fly, fish, mouse,
and a human
What was the first multicellular organism that was sequenced? - ANSWER-C. elegans.
Life cycle is onyl a few days, you can freeze it indefinitely, has a simple body plan
What is the model vertebrate? Why? - ANSWER-Drosophila (fruit fly) because it has
classical genetics, giant chromosomes, trace link between genome and morphology.
Short life cycle, small genome (15 k proteins). Many mutants available
Why does the frog and the zebrafish provide accessible models for vertebrate
development? - ANSWER-Because frog eggs are big, easy to manipulate, and fertilized
QUESTIONS WITH COMPLETE
SOLUTIONS
Define organotrophic - ANSWER-Organisms that feed on other living things or the
organic chemicals they produce
Define phototrophic - ANSWER-Organisms that derive energy from non-living world.
They feed on the sun
Define lithotrophic - ANSWER-Organisms that derive energy directly from nonliving
world. They feed on rocks.
CO2 and N2 are extremely unreactive. True or False? - ANSWER-True
Which atoms are plentiful in nonliving environments? - ANSWER-H, C, N, O, S, P
What is an example of nitrogen fixing bacteria? - ANSWER-Nodules on roots
Which domain of life exhibits the greatest biochemical diversity? - ANSWER-
Prokaryotes
DNA storage of prokaryotes vs eukaryotes - ANSWER-Prokaryotes: DNA is in no
distinct nuclear compartment. Ex. Bacteria, Archaea
Eukaryotes: DNA in membrane bounded nucleus: plants, animals, fungi
Define conservation in terms of genes - ANSWER-Some genes evolve rapidly, others
are highly conserved (slower). A series of mutation events and natural selection
determine how organisms evolve. Ex: rRNA is highly conserved
Most bacteria and archaea have 1000-6000 genes. Why? - ANSWER-Natural selection
favors cells that can reproduce quickly. They maintain a good size to surface area ratio
to maximize uptake of nutrients.
True of False: New genes are generated from pre-existing genes - ANSWER-True
How do viruses work? - ANSWER-They serve as vectors that transfer genetic material.
True or False: Sex is a form of horizontal gene transfer - ANSWER-True
True of False: The function of a gene can often be deduced from its sequence -
ANSWER-True
, How many gene families are common to the three primary branches of life? - ANSWER-
More than 200 gene families
What was one of the spotlights of Molecular Biology? - ANSWER-E.coli
Where are the genomes in eukaryotes? - ANSWER-In chloroplasts and mitochondria -
they are considered to be hybrid genomes. They are degenerate, cut down versions of
original genomes.
How many nucleotides and coded proteins does the mitochondria have in eukaryotic
cells? - ANSWER-16k nucleotides, codes for 13 proteins, 2 rRNAs and 22tRNAs. Many
of the original genes moved into the nucleus
What type of DNA are eukaryotic genomes rich in? - ANSWER-Regulatory DNA
What defines the program of multicellular development in eukaryotes? - ANSWER-The
genome
What is transcriptome? - ANSWER-All transcribed RNA
What is Deep RNA sequencing? - ANSWER-Sequencing the entire RNA repertoire of
RNA from a cell
Why do we use model organisms? - ANSWER-Because we can't sequence all
organisms at once. Need to concentrate efforts and pick a convenient model to focus
research.
What is the model eukaryote? Why? - ANSWER-Yeast: saccharamyces cerevisiae.
Closely related to both animals and plants, has a small genome, and divides indefinitely
in haploid or diploid state.
What is the model plant? - ANSWER-Arabidopsis - Thale Cress (related to mustard).
Grown easily indoors, small thallus and a short generation time of 8 weeks.
What is the world of animal cells represented by? - ANSWER-A worm, fly, fish, mouse,
and a human
What was the first multicellular organism that was sequenced? - ANSWER-C. elegans.
Life cycle is onyl a few days, you can freeze it indefinitely, has a simple body plan
What is the model vertebrate? Why? - ANSWER-Drosophila (fruit fly) because it has
classical genetics, giant chromosomes, trace link between genome and morphology.
Short life cycle, small genome (15 k proteins). Many mutants available
Why does the frog and the zebrafish provide accessible models for vertebrate
development? - ANSWER-Because frog eggs are big, easy to manipulate, and fertilized
