Why cells won't keep replicating?

When humans grow they replicate cells so cell divides and dies this goes for almost every organism. Unicellular organisms have asexual reproduction which means there's only a single parent so they replicate exact copies of themselves like bacteria. Humans and animals go through cellular replication. This is when a cell replicates itself into two cells. The limit is set by telomeres. These are extra ( useless) DNA strands formed at the end of a chromosome. A telomere's basic purpose is to help in cellular replication. The telomere strand at the end of each chromosome reduces every time a cell replicates, so when the telomere's run out in a cell, it dies. And typically women have more telomere's than men leading to a longer life.
                                                  

Comments

Post a Comment

Popular posts from this blog

Vegetable Battery

Image
The energy for the battery comes from the chemical change in the zinc (or other metal) when it dissolves into the acid. The energy does not come from the lemon or potato. The zinc is oxidized inside the lemon, exchanging some of its electrons with the acid in order to reach a lower energy state, and the energy released provides the power. In current practice, zinc is produced by electrowinning of zinc sulfate reduction of zinc with carbon, which requires an energy input. The energy produced in the lemon battery comes from reversing this reaction, recovering some of the energy input during the zinc production.
Read more

Cell Cycle part 2

Image
Now the cell should have double the amount DNA after interphase. The next phase is m-phase. The m-phase consists of mitosis (separation of 1 cell nucleus to 2 nuclei) and cytokinesis (cytoplasmic division or whole cell division). There are 4 steps in mitosis. To help understand this concept, I will explain the structure of a chromosome. A chromosome is formed during mitosis to help in nuclear division. A chromosome has two sides, each side is a copy of the other(interphase), therefore, each side separates into its own nucleus so the new cell has an exact copy of the parent cell's DNA. The first phase is called prophase. During prophase, the chromosomes become visible from chromatin and the nucleolus disappears. The next phase is called metaphase. Here, the chromosomes line up in the center and fibers called spindle fiber attach to the chromosomes centromere from both sides. The next step, anaphase, the spindle fibers pull on the chromosomes where each copy is separated to either s
Read more

How does graphite conduct electricity ?

Image
Graphite can conduct electricity due to the vast electron delocalization ( delocalized electrons are electrons in a molecule, ion or solid metal that are not associated with a single atom or one covalent bond)  within the carbon layers (a phenomenon called aromaticity ). These valence electrons are free to move, so are able to conduct electricity. However, the electricity is primarily conducted within the plane of the layers. The conductive properties of powdered graphite allowed its use as a semiconductor substitute in early carbon microphones.
Read more