science

The Differences Between DNA and RNA Compare and Contrast DNA and RNA Genetic information is the basis for transferring traits from generation to generation. Living organisms use one of two molecule types for the transfer of genetic information. Deoxy ribonucleic acid (DNA) is used in the vast majority of living creatures whereas ribonucleic acid (RNA) has a variety of functions within cells, as well as being used to carry genetic information in some viruses. Both DNA and RNA also have a variety of other functions within living creatures, including the generation of proteins within cells. Structure of DNA DNA is a polymer, which means it consists of many individual repeating molecular units. Each unit within DNA is called a nucleotide and consists of a 5-carbon sugar (deoxyribose), a nitrogen-containing molecule (also known as a base) and a phosphate group. Four different types of nucleotides exist and the only difference between these is the ...

Mitosis and Meiosis                   idea; You started off as a fertilized cell inside your mom, called a zygote. Now, you’re a thriving community of hundreds of millions of cells, all working together towards a common purpose: to keep you alive. How did so many cells come from just one? Generally speaking, the answer is straightforward: many cells come from just one by repeated cell division. Your first form as a zygote split to make two cells. Then those cells split, making four...and so on and so forth, until you became the living, functioning organism you are today. There are two ways cell division can happen in humans and most other animals, called mitosis and meiosis . When a cell divides by way of mitosis, it produces two clones of itself, each with the same number of chromosomes. When a cell divides by way of meiosis, it produces four cells, called gametes. ...

List of systems of the human body Part of a series of lists about Human anatomy General [show] Structures [show] Muscles [show] See also [show] v t e Clockwise from top left: the integumentary skeleta nervous cardiovascular endocrine and muscular systems. Clockwise from top left: the lymphatic respiratory urinary reproductive (female male) and digestive systems. The main systems of the human body are: Cardiovascular system / Circulatory system : Circulates blood around the body via the heart , arteries and veins , delivering oxygen and nutrients to organs and cells and carrying their waste products away. Digestive system / Excretory system : Mechanical and chemical processes that provide nutrients via the mouth , esophagus , stomach and intestines . Eliminates waste from the body. Endocrine system : Provides chemical ...