chapter 10 questions Flashcards
where do scientists gain informatiom from when comparing DNA
in DNA profiles and DNA sequencing
define genome
the complete set of genetic material in a cell, or organisms complete set of DNA
how can the genome be used for evidence for evolution
by compairing the sequence of the human genome with genomes of other organims, researchers are able to compare areas of similarity and difference
why do we only inherit mtDNA from our mothers
after a sperm has pentrated the egg at fertilisation, the mitochondria in the sperm are radidly destroyed. this means that, while our nuclear DNA comes from the nucleus of the egg and the sperm, out mitochondria DNA comes only from the egg
explain why not all retroviruses are endogenous retroviruses, and why only endogenous retroviruses are useful in providing evidence for evolution
Retroviruses copy their DNA or RNA into the host cell through reverse transcription.
The retroviruses will only become endogenous when the DNA or RNA is reverse transcribed into the gametes.
When retroviruses become endogenous, the viral sequence will be passed on to the offspring from the common ancestor, so when comparing different species that share a common ancestor, the ERV would be found at the same location in the chromosome of both species.
state the relationship between DNA, RNA, amino acids and proteins.
DNA contains the code for building proteins. The DNA is transcribed into mRNA and tRNA is used to translate the code into a sequence of amino acids at the ribosome.
Amino acids are the building blocks of proteins. Determining the sequence of amino acids can allow for the determination of the sequence of nucleotides in a DNA molecule.
when comparing amino acid sequences, scientists use a single letter rather then the three letters that are usually used to identify them.
to make comparision of amino acid chains easier, scientists have also adapted a system of coding where by one letter is used to represent one particular amino acid
what is annotation, and why is it part of bioformatics
Annotation is the identification of genes in a DNA sequence. The process needs to be computerised because genome sequences are too large to be annotated by hand.
evolution results from changes in DNA. given this fact, explain why a comparison of the sequence of amino acids in a particular protein can provide evidence for evolution
Amino acids are the building blocks of proteins; their order and number in a protein is determined by the sequence of nucleotides in a gene on the DNA molecule.
Comparing the sequences of amino acids is by proxy, comparing the DNA sequence. The more similar the amino acid sequences, the more closely related the two species are.
