Introduction to study of Genetics - SciPad Pg156

Paragraph: All organisms are made of cells. An adult human contains anywhere from 50 trillion to 100 trillion of them. All human cells contain a nucleus (except red blood cells). The nucleus can be thought of as the “control centre” of the cell as it contains the instructions that tell the cell how to function. These instructions are located on chromosomes. Humans have 46 chromosomes in every cell in their body. 23 of these chromosomes were inherited from your father, and 23 were inherited from your mother. Chromosomes are made of a molecule called deoxyribonucleic acid (DNA). A section of DNA that contains the instructions for a particular feature is called a gene.

DNA stands for Deoxyribonucleic acid

Chromosomes are made up of DNA

Nucleus is where you find chromosomes

Genes are the sections of of DNA that control a feature

Genes control the features and tell our body what our features are

We have 46 chromosomes in most of our body cells

We got these chromosomes from our parents

DNA is shaped as a double helix

Paragraph: The structure of deoxyribonucleic acid (DNA) is the same in all living things. It looks like a twisted ladder, known as a double helix. DNA is made up of simple repeating units called nucleotides. A nucleotide is comprised of sugar, a phosphate and a base. The sides of DNA are made up of the sugar and the phosphate. These sides are linked together by chemicals called nucleotide bases.

There are four different nucleotide bases in DNA - adenine (A), thymine (T), cytosine (C), and guanine (G). Their different chemical make-up means that adenine always bonds with thymine, and cytosine always bonds with guanine. This specific pairing of bases is called the '“complementary base-pairing rule”.