Biology › DNA Structure
How can synteny help with understanding chromosomes?
It can indicate conserved regions
It can indicate crossover events
It can indicate recombination events
It can indicate hybridization
It can indicate recessive neofunctionalization
Synteny is the conservation of order of genes. Being able to see conserved blocks in genes when comparing two chromosomes of the same species, it indicates that at some time in evolutionary history, these blocks originated from a hypothetical common ancestor. Genes that are highly conserved among species are usually vital to the organism's viability. For example, the genes required for glycolysis to occur are required in almost all organisms.
Which of the following is not correct regarding eukaryotic DNA?
DNA is found in the nucleus, cytoplasm, and ribosomes.
Deoxyribose is the sugar that composes DNA.
DNA runs antiparallel in a 5' to 3' direction.
DNA's bases include adenine, guanine, thymine, and cytosine.
DNA is self-replicating.
All of the responses are correct except that eukaryotic DNA is found in the nucleus, cytoplasm, and ribosomes. In eukaryotes, DNA is only found in the nucleus, mitochondria, and only sometimes free floating in the cytoplasm. DNA is not found in ribosomes. RNA on the other hand, is found in the nucleus, cytoplasm, and ribosomes. Note that since prokaryotes lack membrane-bound organelles, their DNA is free-floating in the cytoplasm.
A genome is best described as which of the following?
The entire set of DNA found within all chromosomes
The free floating DNA found outside the nucleus
The DNA specifically found in bacterial cells
A mapping unit for DNA
A computer system for storing DNA information
Based on the definition of genome, it is the entire set of DNA found within all the chromosomes an organism contains. The human genome is contained on 23 pairs of chromosomes, which code for about 25,000 genes.
Which of the following is not correct regarding eukaryotic DNA?
DNA is found in the nucleus, cytoplasm, and ribosomes.
Deoxyribose is the sugar that composes DNA.
DNA runs antiparallel in a 5' to 3' direction.
DNA's bases include adenine, guanine, thymine, and cytosine.
DNA is self-replicating.
All of the responses are correct except that eukaryotic DNA is found in the nucleus, cytoplasm, and ribosomes. In eukaryotes, DNA is only found in the nucleus, mitochondria, and only sometimes free floating in the cytoplasm. DNA is not found in ribosomes. RNA on the other hand, is found in the nucleus, cytoplasm, and ribosomes. Note that since prokaryotes lack membrane-bound organelles, their DNA is free-floating in the cytoplasm.
How can synteny help with understanding chromosomes?
It can indicate conserved regions
It can indicate crossover events
It can indicate recombination events
It can indicate hybridization
It can indicate recessive neofunctionalization
Synteny is the conservation of order of genes. Being able to see conserved blocks in genes when comparing two chromosomes of the same species, it indicates that at some time in evolutionary history, these blocks originated from a hypothetical common ancestor. Genes that are highly conserved among species are usually vital to the organism's viability. For example, the genes required for glycolysis to occur are required in almost all organisms.
A genome is best described as which of the following?
The entire set of DNA found within all chromosomes
The free floating DNA found outside the nucleus
The DNA specifically found in bacterial cells
A mapping unit for DNA
A computer system for storing DNA information
Based on the definition of genome, it is the entire set of DNA found within all the chromosomes an organism contains. The human genome is contained on 23 pairs of chromosomes, which code for about 25,000 genes.
Which sugar is found in the back bone of DNA?
Deoxyribose
Ribose
Dextrose
Dextran
DNA stands for "deoxyribonucleic acid." The backbone of DNA is comprised of alternating sugar and phosphate units, in which the sugar is deoxyribose. The backbone of RNA is also comprised of sugar and phosphate units, but uses the sugar ribose.
Which sugar is found in the back bone of DNA?
Deoxyribose
Ribose
Dextrose
Dextran
DNA stands for "deoxyribonucleic acid." The backbone of DNA is comprised of alternating sugar and phosphate units, in which the sugar is deoxyribose. The backbone of RNA is also comprised of sugar and phosphate units, but uses the sugar ribose.
Operons __________.
are sets of genes that are often regulated together
are only found in eukaryotes
often involve multiple chromosomes
are always involved in protein synthesis
More than one of the other answer choices is correct.
An operon is a segment of DNA that is under the control of a single promoter. For example, if there are three genes required for breaking down a sugar in an operon, they will all be activated together. This makes sense, as there is no sense in activating only one or two of these genes, since all three are required to break down the sugar. For example, the control element that turns on the operator can be the sugar itself. It should make sense that the genes required to break down a sugar are only turned on if that sugar is present.
Operons __________.
are sets of genes that are often regulated together
are only found in eukaryotes
often involve multiple chromosomes
are always involved in protein synthesis
More than one of the other answer choices is correct.
An operon is a segment of DNA that is under the control of a single promoter. For example, if there are three genes required for breaking down a sugar in an operon, they will all be activated together. This makes sense, as there is no sense in activating only one or two of these genes, since all three are required to break down the sugar. For example, the control element that turns on the operator can be the sugar itself. It should make sense that the genes required to break down a sugar are only turned on if that sugar is present.