lesson 1: Introduction
Key words:
-DNA
-Double Helix
-Base Pair
-Chromosome
-Sister Chromatids
Genetics is the study of an organism's DNA. DNA is a molecule that lives inside the nucleus of pretty much every cell in the body. It codes for any living thing's heritable characteristics. Half of the offspring's DNA comes from each parent. DNA codes for things like eye color, susceptibility to disease, gender, blood type, and (some) personality traits.
DNA is in a double-helix structure, like a twisted ladder. The long parts are made up of phosphates and sugars. The 'rungs' are the four nitrogenous bases: adenine, guanine, thymine and cytosine. Adenine attaches only to thymine. Guanine attaches only to cytosine. Organisms are unique because of different arrangements and numbers of each of these pairs.
If you stretched all the DNA in all of your cells combined, the resulting string would be about twice the diameter of the Solar System! That means DNA is difficult to stuff into a tiny little nucleus. That's where histones come in, twisting your DNA into shapes called chromosomes.
Each chromosome is made up of several parts. Most important to know are the sister chromatids and centromere. The chromatids hold the same genes, and are copies of each other (as far as genes go, but we'll get to that later). These chromatids are called sister chromatids - because they hang out together.
Rabbits, like humans, have 22 pairs of autosomal (regular) chromosomes, and 1 pair of sex chromosomes (X and Y) which determine gender and sex-linked characteristics.
-DNA
-Double Helix
-Base Pair
-Chromosome
-Sister Chromatids
Genetics is the study of an organism's DNA. DNA is a molecule that lives inside the nucleus of pretty much every cell in the body. It codes for any living thing's heritable characteristics. Half of the offspring's DNA comes from each parent. DNA codes for things like eye color, susceptibility to disease, gender, blood type, and (some) personality traits.
DNA is in a double-helix structure, like a twisted ladder. The long parts are made up of phosphates and sugars. The 'rungs' are the four nitrogenous bases: adenine, guanine, thymine and cytosine. Adenine attaches only to thymine. Guanine attaches only to cytosine. Organisms are unique because of different arrangements and numbers of each of these pairs.
If you stretched all the DNA in all of your cells combined, the resulting string would be about twice the diameter of the Solar System! That means DNA is difficult to stuff into a tiny little nucleus. That's where histones come in, twisting your DNA into shapes called chromosomes.
Each chromosome is made up of several parts. Most important to know are the sister chromatids and centromere. The chromatids hold the same genes, and are copies of each other (as far as genes go, but we'll get to that later). These chromatids are called sister chromatids - because they hang out together.
Rabbits, like humans, have 22 pairs of autosomal (regular) chromosomes, and 1 pair of sex chromosomes (X and Y) which determine gender and sex-linked characteristics.