Withstand turgor pressure-turgor pressure is the force exerted against the cell wall as the contents of the cell push the plasma membrane against the cell wall.
Answer:
Receptors are highly specific and only have high affinity for those ligands for whom they are specific.
Explanation:
Receptors are proteins that receive a stimulus or bind a ligand and mediate effects via receptor effector system.
Receptors are macromolecules that are highly specific.
The affinity between the ligand and the receptors is determind by the disassociation constant Kd.
The receptors produce maximun effect when an appropriate specific stimulus is present.
Different recptors types are present for different ligands.
For example, muscrinic receptors are specific for acetycholine and adrenergic receptors are specific for adrenaline/nor adrenaline.
It is important to know the specificity so that the body remains in a state of balance.
A.) Light traveling from the sun to my car seat
Answer:
- New seedlings: histone acetylation
- After cold exposure: histone methylation
Explanation:
Vernalization is an adaptive mechanism whose objective is to ensure that flowering occurs only after winter (i.e., after cold conditions). In certain plants, this process (vernalization) suppresses the expression of genes that encode repressors of flowering. In <em>Arabidopsis</em>, vernalization is associated with histone modifications at <em>FLC</em> chromatin. The <em>FLOWERING LOCUS C </em>(<em>FLC</em>) is a MADS-box gene that acts as a repressor of flowering in <em>Arabidopsis</em>. Epigenetic modifications control the expression of the <em>FLC</em> gene. The <em>FLC</em> gene is expressed at low temperatures due to histone acetylation at <em>FLC</em> chromatin, and thereby the expression of <em>FLC</em> mRNA transcripts ensures that the <em>Arabidopsis</em> plant cannot flower. Subsequently, as the <em>Arabidopsis</em> plant is exposed to cold, <em>FLC</em> is repressed by the accumulation of trimethylation on lysine 27 of histone 3 (H3K27me3), thereby allowing it to flower when temperatures become warmer.
Answer:
<u><em>B. Smooth Muscle</em></u>
Explanation:
Medusae are among the simplest animals that use muscles to make rhythmic movements. In at least some medusae, the circular muscles, which do most of the work of swimming, are striated. In contrast, most of the other muscles of cnidarians are <u><em>smooth</em></u>.
