Answer:
Embedded in the lipid bilayer are large proteins, many of which transport ions and water-soluble molecules across the membrane. Some proteins in the plasma membrane form open pores, called membrane channels, which allow the free diffusion of ions into and out of the cell.
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.
<h3>Question from alternative source</h3>
Many different types of mutations can occur within the body. Cystic fibrosis is a genetic disorder that is caused by different mutations within the CFTR gene. One mutation in the CFTR gene that leads to cystic fibrosis causes translation to end earlier in the gene sequence. Which type of mutation causes this translation error that leads to cystic fibrosis?
- silent
- missense
- nonsense
- deletion
Answer:
Nonsense
Explanation:
Nonsense mutations describe mutations that produce a premature stop codon. The stop codons are UAG, UAA, and UGA. A way in which this could arise is, for example, if there was a substution of a nucleotide in the mRNA codon UAC (which codes for the amino acid Tyrosine) to the nucleotide UAG (which codes for a stop codon).
The translation machinery would reach this codon, which signals that translation should be terminated. This would mean that the mRNA would be released, and a truncated (shortened) version of the amino acid would be produced. This is likely to be non-functional, and may even be marked for destruction by the cell.
The positioning of the body where are major body parts are flexed is called the fetal position. In this position the back is arched forward and arms and legs are drawn closer to the torso and the head bowed. It is called this because this is the position the fetus is in as it develops in the womb.
Answer:
Please see below
Explanation:
Between all these kids carrying out this discussion, Tamara is the closest to guessing what scientists do. There is indeed a definite set of steps that scientists undertake in order to conduct science experiments. The scientific method is as follows:
- observation
- measurement
- experiment
- testing the hypothesis
