Antibiotic resistance happens when an antibiotic lost its ability in controlling or killing bacterial growth. At this moment the bacteria are already resistant to the antibiotic and are multiplying even though the drug is present. This is a natural phenomenon.
The answer is; cell surface receptors that are recognized as antigens by the recipient's immune system.
Therefore the organ is attacked as a foreign substance . This is why organ transplants are given by the closest family member to reduce the antigen variability that causes transplant rejection. Tissue typing is done to ensure that the organ or tissue is as similar as possible to the tissues of the recipient.
Microorganisms can be divided into two groups:
1. Archea
• Archea are prokaryotic unicellular organisms without cell nucleus or other membrane bound-organelles.
• Their membrane is built from ether lipids, which differs them from bacteria’s cell membrane.
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2. Bacteria
• Bacteria are also unicellular prokaryotic organisms.
• Bacterial cell membranes are made from phosphoglycerides with ester bonds. Bacterial genome is in a form of circular chromosome.
• They reproduce by binary fission or by budding.
Besides, prokaryotes (Archea and Bacteria) a large number of eukaryotes are also microorganisms. Unicellular eukaryotes contain organelles such as the cell nucleus, the Golgi apparatus and mitochondria. Usually, they reproduce asexually by mitosis. An example of eukaryotic microorganism is Protist.
The right answers are mentioned in the picture.
A base pair (bp) is the pairing of two nucleobases located on two complementary strands of DNA or RNA. This pairing is carried out by hydrogen bridges. There are four types of nucleic bases: A-T-C-G, these letters for Adenine, Thymine, Cytosine, and Guanine. A with T and C with G.
It is also necessary to take into account the antiparallel character of the DNA strands. If a strand is in the 5 '3' direction, its complete strand is in the 3 '5' direction.
The correct answer is stabilising selection. This is selection that favours an average trait value. It is thought that this sort of selection is very common as traits among most animals do not appear to change drastically over time. Stabilising selection selects against the extreme traits, and leads to a decrease in genetic diversity by favouring the average phenotypes.
