Red blood cells will swell and burst. The
reason behind this is that red blood cells are okay when they are in
the plasma (the watery part of the blood) because the solutes in plasma
are so well balanced that plasma is rendered isotonic. An isotonic
solution is a type of solution that has the same salt concentration as
its surrounding environment and thus the substances around it e.g. cells
neither gain nor lose water. In the blood plasma, the red blood cells
neither lose nor gain water and so they remain intact.<span>However distilled
water is hypotonic (has less or no solutes) and therefore osmosis will
take place when red blood cell which have a higher solute concentration
are placed in it. Water molecules will leave the distilled water and
pass into the red blood cells through the semi-permeable membrane of the
cells in an attempt to equalize the difference in osmotic pressure on
either side of the membrane. In so doing, water will accumulate in the
cell which will then swell to capacity and ultimately burst.</span>
<span>B. The characteristic (blue eyes) is carried in a recessive gene. </span>
organisms with phenotypes that are beneficial for survival are more likely to reproduce and pass on their genetic information. Over lots and lots of generations, this progressively leads to changes in the species as a whole
Answer:
adaptive; innate
Explanation:
The adaptive immune system refers to a specific type of immunity which is found only in vertebrates. Adaptive immunity is defined by the presence of specialized immune cells (i.e., lymphocytes such as T and B cells). The B cells produce molecules known as antibodies which destroy specific pathogenic microorganisms (e.g., bacteria, viruses) and thus prevent diseases in the future. On the other hand, the innate immune system is the first (and evolutionary more ancient) defense line against pathogenic infections or tissue injury. Innate immunity includes, among others, physical barriers, anatomical barriers, phagocytic enzymes (i.e., lysozymes), phagocytic cells (i.e., macrophages), inflammation, etc. Inflammation is defined as an innate immune response composed of complex biological processes that protect the body by eliminating harmful microorganisms and intracellular danger signals, thereby regulating signaling pathways of many diseases.
Answer:
d. The cell walls of bacteria are composed of peptidoglycan
Explanation:
Bacterial cell wall is made of peptidoglycan or murein. It is made of sugars and amino acids. Sugar component consists of N-acetylmuramic acid (NAM) and N-acetylglucosamine (NAG) alternating residues. A peptide chain of three to five amino acids is attached to NAM.
Gram positive bacteria have thick cell wall made of many peptidoglycan layers. Whereas gram negative bacteria have a thinner layer. The peptidoglycan cell wall is required for the survival of the bacteria hence it is targeted by many antibiotics like penicillin.
