Answer:
The binding of chemical messengers to receptors often results in a shape change, which affects receptor function.
Explanation:
Binding of specific chemical messengers to the corresponding receptors of target cells brings about change in the shape of the receptors. This structural change in the receptor results in the generation of the desired response. It reflects how the form and specific configuration of substances or biomolecules affect their functions.
For example, binding of neurotransmitters to the receptors present on neurons opens the associated ligand-gated ion channels to allow the movement of specific ions through it. In the absence of bound ligand, these channels are present in a closed conformation.
Weathering can be caused by rain,snow,heat,and as well as wind.
Advantage: Dichotomous keys are very useful because they allow non-expert users to identify organisms by directing them to look at the known, important organisms. Disadvantage: Disadvantage of dichotomous keys is that if a single wrong decision is made at any juncture, a wrong identification will result. Sometimes it becomes obvious that an error has been made, and you can retrace your steps until you get back on the right track, but this is not always the case
Enzymes can be best described as catalysts in living systems. This is because enzymes accelerate chemical reactions without being used up in the process.
Answer: b. Muscles
A metazoa is a division of animal kingdom that includes all animals expect protozoa and sponges. Metazoa division includes multicelluar animals, which exhibit highly differentiated cells. They have muscular and nerve system and well coordinated tissues and organs. Locomotion requires a coordination activity of muscular, skeletal and neural system. It is mainly achieved by contraction and relaxation of muscles that occurs due to specialized muscle proteins named as actin and myosin which receives signals from nerves.
Hence, locomotion in metazoa is due to contraction of muscles.
