Question

The codon for the amino acid _______ doubles as the start codon. Frameshift mutations insert or delete nucleotides, shifting the _______ of the mRNA message. _______ mutations, inherited from parents, are present in every cell in the offspring.

Answer 1

1. methionine

2. reading frame

3. Germline

4. A mutation is a change in the DNA of an organism. Because DNA is the heritable substance of life and is comprised of individual nucleotides, changes in nucleotides can lead to changes in the DNA. DNA mutations can be very small, on the order of a single nucleotide, or very large, affecting entire segments of a chromosome. DNA mutations in protein coding regions can change the proteins produced by the ribosome and either reduce or boost function because of such changes.

5. Any mutation that results in severe dysfunction will lead to the death of the organism, and therefore, that mutation is less likely to be passed on to future organisms. On the other hand, mutations that promote the survival of an organism will be passed on to the organism's offspring.

6. Frameshift mutations are additions or deletions of nucleotides that shift the reading frame of the DNA or RNA and cause different codons to be expressed. For example, a single deletion of a nucleotide can cause all of the codons downstream of the deletion to undergo a frameshift mutation and code for entirely different amino acids. A single nucleotide deletion or addition also can create stop codons that shorten the amino acid polypeptide. Frameshift mutations, which are inherited, are very debilitating and often fatal.

7. The two types of mutations that can occur in humans are germline and acquired, or somatic, mutations. Germline mutations are inherited from one's parents, while somatic mutations occur as a result of environmental factors.

Step-by-step explanation:

penn foster

Answer 2

• The codon for the amino acid Methionine doubles as the start codon.
• Frameshift mutations insert or delete nucleotides, shifting the Open Reading Frame of the mRNA message.
• Germline mutations, inherited from parents, are present in every cell in the offspring.

Step-by-step explanation:

The codon for the amino acid Methionine doubles as the start codon.

The start codon in a mRNA is AUG. When a ribosome finds this sequence of nucleotides translation starts, and the first amino acid assembled in the nascent protein is Methionine.

Frameshift mutations insert or delete nucleotides, shifting the Open Reading Frame (ORF) of the mRNA message.

After the first AUG is detected by the ribosome, it moves through the mRNA every three nucleotides (a codon). The way in which the mRNA sequence is read by the ribosome is called the ORF, and it determines which amino acids will be assembled in the translated protein.

However, frameshift mutations change the codons the ribosome reads and therefore the ORF, so the amino acids in the protein will end up being different.

Germline mutations, inherited from parents, are present in every cell in the offspring.

A zygote is formed when a maternal gamete combines with a paternal gamete. In order for a mutation to be present in every cell of the offspring, it must have been inherited from the parents and present in their gametes. The germ cells develop into the gametes (egg and sperm cells in women and men, respectively), so the mutations present in them which are inherited by the offspring are called germline mutations.