There is a particular balance in the cells in all life forms.
While we might think that the cells get bigger as we grow older, the fact is that the cell sizes stay the same, we just get more cells as we mature.
Our cells have to maintain a particular size and as old cells die off, new ones replace them. Each cell has an outer membrane that protects the cell from danger while also letting nutrients and food in and getting rid of waste.
If our cells kept growing the membrane would not be able to do its job and the cell might become sick or even die.
To accomplish the task of maintaining the balance, cells divide to reproduce and make new fresh cells. Each cell has specific jobs to do and the new ones take the place of older cells.
Cells are called the “basic building blocks” of living things as well as the fundamental units of life.
Scientists have estimated that our bodies contain between 75-100 trillion cells. Our cells do everything from give us energy to structure and even a method to reproduce.
Why cells have to be so small
The main reason that cells are required to be small is so that they can maximize their ratio of surface area to volume.
What that means is the calls have a better chance of letting ions and molecules move across a smaller area to be successful in meeting the cell membrane.
To be efficient, cells also have to get both the food and waste in and out quickly. A larger size would make this a lot more difficult.
Eukaryotic Genetic Material
Eukaryotic cells are self-contained little factories and each of these types of cells has both RNA and DNA in its nucleus.
These are the key elements that are needed for the individual instruction for each cell and these molecules are known as nucleic acid.
The major components of the DNA molecules in human cells are the pairs of 23 chromosomes (totaling 46). There are 22 pairs of chromosomes that are called “autosomes” (non-sex chromosomes) and one pair of chromosomes that have to do with sexual identification that are the “X” and “Y” chromosomes.
Prokaryotic Genetic Material
Prokaryotic cells are those that don’t have a nucleus. Their DNA freely floats coiled up in the cytoplasm in an area known as the “nucleoid region.”
Cells Reproduce in Different Ways
A variety of cells have their own way of reproducing and each one meets the needs of the species. Almost all of the prokaryotic cells reproduce through the “binary fission” process.
This could be compared to cloning, where two identical cells are created out of the original one.
Eukaryotic organisms reproduce through the process of mitosis to create two daughter cells from one parent cell, as well as sexual reproduction which makes use of the fusion of two different sexual cells known as gametes.
There are two main reasons that cells divide: Meiosis is related to reproduction and mitosis is for replacement or repair of a cell.
Facts about Cell Division
- Bacteria reproduce fairly fast using binary fission, and they form entire colonies that resemble each other genetically.
- When you fall and hurt yourself, the location of the injury becomes an emergency signal to your body. There is an immediate trigger to send out “growth factor” substances as well as those that tell the cells to stimulate cell and tissue repair.
- Both protein production and cell growth stop at the last stage of the mitosis cell cycle.
- Cells do reach a time when they stop the normal cell cycle and stop dividing. This can happen during a resting period that is either temporary or permanent or when it reaches the end of its development stage.
- Growth occurs in a kind of plan that helps to determine the shape and size of the individual organism. Growth can be restricted to certain areas.
- Just prior to the part of the cell life involved in distributing chromosomes, the mother cell can often grow twice its original size.
Interesting Facts about Biology
- If we got rid of all cardiovascular diseases, people would live 9.78 years longer.
- We can’t see our taste buds with the naked eye. There are little bumps on the human tongue called “papillae” and they rest on top of the taste buds.
- Your little finger contains over 50% of the total strength of your hand.
- Babies are born with farsightedness. They begin to change focus at the age of 3-6 months of age.
- An adult human body is made up of over 100 trillion cells.
The cells in the human body can be in over 200 different types with many different forms.
Cell Division Quiz
Now let's test what you have learned!
