<span>At least 50% of the variation in the trait in the population is due to genetic differences.</span>
Eukaryotes are organisms whose cells have a nucleus enclosed within a nuclear envelope.
Answer:
I say the correct answer is the 3rd one.
Explanation:
Answer is number 3
Answer:
Answer is C.
Explanation:
For A and B, a base substitution affects one of the three bases that comprise a codon, the DNA/RNA unit that corresponds to a particular amino acid. If one base is substituted, one codon and therefore one amino acid will be affected. Codons have built-in redundancy, so even by changing one base, the new codon sometimes still corresponds to the same amino acid. Therefore, a base substitution at most affects one amino acid, and sometimes doesn't affect it all.
Frameshift mutations cause a lot more trouble. These occur when you have a deletion or insertion that changes the number of bases in your gene. As a result, the "frame" of the codons changes (everything shifts one way or the other by the number of bases added/removed). This affects EVERY codon downstream of the mutation, so you can imagine that such a mutation would have a bigger effect the closer to the start of the gene it occurs. This is why C is correct.
Answer:
Around 4.1 billion years ago, the first single celled life form appeared on Earth
