What is a major difference between prokaryotes and eukaryotes?
a. prokaryotes have no nucleus.
b. all prokaryotes cause disease.
c. eukaryotes contain more mitochondria.
d. nucleic acids are founds only in eukaryotes.

The correct answer is A) Prokaryotes have no nucleus.

Prokaryotes are the single celled organisms, which do not possess a well defined membrane bound nucleus and other organelles. The genetic material is all these organisms is present in the cytoplasm of the cell.

Example- Bacteria.

Whereas, eukaryotes are single or multicellular organisms, which possess a well defined nucleus ( with genetic material in it) as well as other organelles like mitochondria, golgi complex, endoplasmic reticulum.

Example- Plant cell.

Thus, option A) is the right answer.

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave