The DNA replication by the action of DNA polymerase takes place in the 3' to 5' direction on the leading strand. The lagging strand which has the opposite orientation or polarity as that of the leading strand requires a more time to get synthesised. The DNA replication of the lagging strand happens in short segments where a RNA primer forms a compliment with a part of the DNA segment on its 3' end. This RNA primer helps initiate the replication of the Okazaki fragments. When the replication on the lagging strand reaches its end, the RNA primer forms a compliment with the last bit of the strand. This small segment gets missed in the end as no more DNA is left to form a RNA primer-DNA compliment. Such shortening of the lagging strand in the replication process is the end-replication problem.
Telomeres are protective ends of the DNA strands. These ends contain a poly-A tail. When the lagging strand replication reaches its end, the RNA primer forms a compliment with the telomere and initiates the replication. This leads to the shortening of the telomere and not the coding segments on the lagging strand of DNA. The telomerase repairs the shortened telomere by re-synthesising it.
Answer:
The primary function of the plasma membrane is to protect the cell from its surroundings. Composed of a phospholipid bilayer with embedded proteins, the plasma membrane is selectively permeable to ions and organic molecules and regulates the movement of substances in and out of cells.
Explanation: can u give me 5 stars?
Answer:
Severage water is most desasterous thing of urbun areas.
noise pollution also damage species
Explanation:
severage water contaminates rivers,canals and other water reserviours that can be harmfull for fish comunity moreover animal may drink water from that water bodies that causes problems in them.
contaminated water from industries also effects water bodies.
noise pollution disturb mental life of man as well as animals .
Answer:
Sudden Influx of Nutrients
Explanation:
Algal blooms are caused by a sudden influx of nutrients, coupled with already warm temperatures. This can happen from fertilizer runoff from farms or chemical industry waste. They allow algae to quickly grow, but the water reaches carrying capacity.
Answer:
Option C. It is found only in a eukaryotic cell.
Explanation:
Plasma membrane is also called cell membrane. It is found in all cells of living organisms both unicellular and multicellular. It controls the amount of nutrients and wastes entering or leaving a cell. Due to permeability, the substances are easily pass through. Plasma membrane also act as boundary of animal cell.
