Answer:
b: many genes code for RNAs that function directly in the cell
Explanation:
<em>The central dogma</em> theory describes the basic framework for gene expression in living organisms. Genetic information from DNA is encoded or transcribed as RNA which then becomes translated as proteins.
The processes that take place for gene to be successfully expressed are;
- Replication
- Transcription
- Translation
<em>Replication</em> is a process whereby DNA makes a copy of itself to be distributed in daughter cells during cell division.
<em>Transcription</em> is the process whereby genetic information in DNA is encoded as RNAs. The RNAs are short-lived as they are quickly utilized in protein synthesis or <em>translation </em>process.
Hence, the RNAs do not function directly in the cells but mere intermediaries in the synthesis of proteins.
<em>The correct option is b.</em>
The main responsible for the delay among the atrial and
ventricular contractions is the action potential conduction velocity of the AV
node cells. If the atria and ventricles contract simultaneously, atria cannot
give any help in filling the ventricles, which is needed, especially in those
with stiff ventricles as in the elderly. Hence atria have to contract first and
then the ventricles.
The human gene for insulin production is identified and removed using enzymes called restriction enzymes. The same restriction enzymes are used to cut open a plasmid (a small, circular section of DNA).
Genetics affects speciation mostly via mutation caused due to adaptation and environmental conditions.
Explanation:
- The Speciation is defined as the evolution of a species into a distinct species. The cause of this could be several, and some of them could be environmental conditions, mutations, etc
- Environmental conditions include isolation of the species caused by mountain rise, river, flood etc. to survive they have to evolve or get adaptations to living in those conditions
- Mutation happens for many reasons, external factors can also cause the mutations to occur. It will also lead to speciation.
