Answer:
A frameshift changes every codon past it. A base substitution only changes one codon.
Explanation:
DNA is comprised of nucleotides (A, C, T, G) that make up amino acids. Every three bases is called a codon and represents an amino acid.
In a frameshift mutation, a nucleotide is either added or deleted from the sequence. This offsets the entire sequence after it because the reading frame shifts. Here's an example:
ACTGCTATCGTCATC
If another T is added in between the first and second codons, then every codon after will be changed.
ACT>T<GCTATCGTCATC
A substitution mutation is usually less severe, as it only alters one codon in the sequence. These occur when one nucleotide is replaced by another one. Here's an example:
ACTGCTATCGTCATC
Let's say the first G is replaced by a T.
ACT>T<CTATCGTCATC
As you can see, none of the other codons changed.
Typically, a frameshift mutation is considered worse than a substitution mutation.
Answer:
Dolphins use their strong snouts as a powerful weapon to ram sharks, targeting their soft underbellies and gills to cause injuries. Sharks pose less of a threat to larger members of the dolphin family. Indeed, orcas are the top predator in the ocean and small sharks are a target for some populations.
Answer: The “graying of America”
Explanation: Just took the test
This is the chronicle of evolution over millions of years of geologic time engraved in the order which fossils appear in rock strata.