Answer: Substances that are protein based cannot cross the lipid cell membrane, but can exert their effect by binding to the proteins based receptors present on the lipid bilayer.
Explanation:
Hormones such as calcitonin , Parathyroid hormone and pituatry horomones are proteins and water soluble.They cannot cross lipid bilayer but can bind to ligand binding protein receptors.
These receptors are protein macromolecules that are specific in nature for specific hormones.
After binding to the receptors, these hormone-recpetor complexes activate second messengers and regulate the downstream effects.
<span>C. I and III only is the answer hope i helped</span>
The chemical formula for water is H2O which means that every molecule of water has 2 atoms of hydrogen (H) and one atom of oxygen (O). Here comes the key part. From the Periodic Table of Elements, one sees that one molecule of oxygen atoms weigh 16 grams.
I apologize if this is not what you meant. If you have further questions just tell me.
Answer:
D. Hypothesis.
Explanation:
A hypothesis is defined as an idea or explanation which can be further tested through study and experiments. It is a proposed explanation for a phenomenon.
Scientists generally base scientific hypotheses on previous observations that cannot be explained with the available scientific theories.
<span>1. Introduction of a different environmental pressure, like an invasive species or a prolonged natural disaster.
2. Random mutation, where a gene or set of genes in an individual organism is randomly different from the normal type of that gene in the larger population. This individual may gain an advantage from this mutation and its offspring will inherit the advantageous trait.</span>