Answer:
1- The polar section of a phospholipid is the part with the phosphate group. This is sometimes called the polar head of the molecule.
2- The phosphate group is the negatively-charged polar head, which is hydrophilic. The fatty acid chains are the uncharged, nonpolar tails, which are hydrophobic.
Explanation:
The DNA polymerases are enzymes that create DNA molecules by assembling nucleotides, the building blocks of DNA. These enzymes are essential to DNA replication and usually work in pairs to create two identical DNA strands from one original DNA molecule. During this process, DNA polymerase “reads” the existing DNA strands to create two new strands that match the existing ones.
Every time a cell divides, DNA polymerase is required to help duplicate the cell’s DNA, so that a copy of the original DNA molecule can be passed to each of the daughter cells. In this way, genetic information is transmitted from generation to generation.
Before replication can take place, an enzyme called helicase unwinds the DNA molecule from its tightly woven form. This opens up or “unzips” the double stranded DNA to give two single strands of DNA that can be used as templates for replication.
DNA polymerase adds new free nucleotides to the 3’ end of the newly-forming strand, elongating it in a 5’ to 3’ direction. However, DNA polymerase cannot begin the formation of this new chain on its own and can only add nucleotides to a pre-existing 3'-OH group. A primer is therefore needed, at which nucleotides can be added. Primers are usually composed of RNA and DNA bases and the first two bases are always RNA. These primers are made by another enzyme called primase.
Although the function of DNA polymerase is highly accurate, a mistake is made for about one in every billion base pairs copied. The DNA is therefore “proofread” by DNA polymerase after it has been copied so that misplaced base pairs can be corrected. This preserves the integrity of the original DNA strand that is passed onto the daughter cells.

A surface representation of human DNA polymerase β (Pol β), a central enzyme in the base excision repair (BER) pathway. Image Credit: niehs.nih.gov
Structure of DNA polymerase
The structure of DNA polymerase is highly conserved, meaning their catalytic subunits vary very little from one species to another, irrespective of how their domains are structured. This highly conserved structure usually indicates that the cellular functions they perform are crucial and irreplaceable and therefore require rigid maintenance to ensure their evolutionary advantage.
Answer:
The answer is A.
Explanation:
The inner ear parts are responsible for one of the most important sensory responsibilities in our body which is the keep us in balance and provide us with a sense of stability. It is made of three parts named semicircular canals, vestibule and cochlea.
The structure that contains the receptors mentioned in the question and helps us with our head movements to keep our heads horizontally and vertically in the correct position is called "The Saccule" and it is a part of the vestibule part of the inner ear.
I hope this answer helps.
Answer:
An organelle is a subcellular structure that has one or more specific jobs to perform in the cell, much like an organ does in the body.
Explanation:
Some examples of organelles are endoplasmic reticula, Golgi apparatus, lysosomes, vacuoles, mitochondria, plastids, and nucleus.
The correct answer is C and D, which are plant cells.
