Answer:
photosynthesis and the erosion of limestone
D. The macronucleus does not disintegrate during conjugation.
The macronucleus contains the working copies of genes needed to support an enormous cell. It is formed by a division of the fused diploid nucleus after conjugation followed by multiple rounds of internal gene replication which does not occurs in the micronucleus.
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.
The amount of light with not effect the rate of photosynthesis
Answer:
According to the diagram, cell growth and preparation occur in steps 2 and 4, corresponding to phases G₁ and G₂ of cell cycle.
Explanation:
G₁ phase consists of the beginning of the cell cycle, following the process of previous division, and occurs in a cell that prepares for a next division. In this phase growth depends on the proliferation of mRNA to increase protein synthesis.
G₂ phase —third phase of the cycle— is the continuation of the process of cell growth induced by protein synthesis. Changes occur at the level of cellular components, as preparation of the cell prior to division.
