You hear the word DNA all the time. On television, the bad guy (or girl) is always caught because their DNA was found at the crime scene. So, what exactly is DNA?
DNA, also known as deoxyribonucleic acid, is a long, two-stranded molecule that has your personal genetic code. Similar to a cookbook, it holds all the recipes that make up the protein in your body.
Your genome is made up of your DNA. If you are wondering what genome is, it is an organism’s complete set of genetic instructions. Interestingly, each genome contains all the necessary information to create an organism.
Your DNA contains four basic building blocks: adenine, cytosine, guanine, and thymine. The order of these building blocks develops the instruction of the genome.
DNA is shaped like a twisted ladder or two strands of the candy Twizzlers. Each of the two strands of DNA has a beginning (five prime) and an end (three prime). They run in opposite direction of one another, so one strand is 5’ 3’ and 3’ 5’.
The genome for humans is made up of more than three million bases of DNA. The reason is that other organisms have different genome sizes.
One of the main reasons that we study cells and their development is to gain a deeper understanding of ourselves as the beings that house the cells.
Without cells, we would cease to exist.
Cells in our bodies, an other animal bodies is what allows us to gain energy via secondary source from the sun, build our bodies using the elements provided within our environment and obtain oxygen to feed those cells and keep them working properly.
Cells basically rely on a process called Cellular Respiration (to be discussed) and in it’s easiest form can be said in this way: We eat food and breathe so that we release energy. That energy is then used in our bodies to take care of the biochemical processes that are needed for life. (more…)
If you were to take a small toothpick and scratch the surface of your skin or even the inside of your mouth and put that on a microscope slide, you would be delighted to see hundreds of tiny little units with small dots in the center of them.
These are called cells and are 100% what you are made up of. (more…)
There are many things in this world that we live in, however the ones that are living have the same characteristics of another and allow us to distinguish living from non-living.
The term organism refers to living things.
To say that all organisms have the same characteristics of life is accurate and would include the traits that will be mentioned in this post.
Some living things may make us think that they are not living and therefore, it is essential to know the characteristics of life in order to understand the world, living things and yes even ourselves, better.
Before the 1600’s people use to think that nonliving things would magically turn into living things.
Here are some examples of the funny things people use to think:
Straw turned into mice.
Grain turned into mice.
A buried oxen head turns into a fly.
Meat makes flies.
Fruit turns into flies.
Water made Frogs.
These are silly aren’t they?
But this was all before the cell was seen and before anyone knew the characteristics of living things.
The characteristics of living things follow some very general rules that allow us to determine if they are alive or not.
Here are six characteristics of living things used by scientists:
All living things are made of cells (more about cells in another post…this is HUGE!)
All living things need and use energy. (They get it from the sun. Some use it directly while other have to obtain it indirectly)
All living things GROW and DEVELOP.
All living things make more living things – Reproduction.
All living things respond to their environment. (response and stimuli)
All Living things adapt to their environment
In order to be considered alive, ALL of the characteristics of living things MUST be followed at some point in their life cycle. A good example of something that has some of these characteristics but is not alive is camphor.
If you take a bit of camphor and put it into water it will buzz around like it is alive (response to environment) but it is not living and it does not reproduce no is it made of cells.
Can you think of some other examples of nonliving objects displaying living characteristics?