Vocabulary
Big Ideas Heredity and Reproduction Understand and explain that every organism requires a set of instructions that specifies its traits, that this hereditary information (DNA) contains genes located in the chromosomes of each cell, and that heredity is the passage of these instructions from one generation to another.
DNA is a large molecule in each cell that holds its genetic information This genetic information is used by the cell to make proteins It appears in all living organisms How big is human DNA? Estimates vary from between 1.5 and 3 m long Other organisms have DNA with shorter or longer strands
Information for all traits of an organism located in its DNA DNA found in the nucleus of eukaryotes, cytoplasm of prokaryotes
The twisted shape of a DNA molecule is known as a double-helix of two strands composed of a sugarphosphate backbone connected by nitrogen bases There are four different nitrogen bases in DNA Adenine (A) Thymine (T) Guanine (G) Cytosine (C) They form base pairs, one on each of the two strands in the double-helix A pairs with T C pairs with G
Draw this DNA double-helix into your notebook
You can refer to a strand of DNA by its sequence of bases A small example: ATGACGTAC The sequence of bases forms a genetic code Every three bases code for an amino acid Amino acids are the building blocks of proteins A sequence of three letters allows for up to 64 amino acids In reality, there are only 20 amino acids Some have more than one code A few codes are used for other things
Chromosomes DNA is organized into structures called chromosomes Individual parts of a chromosome are called genes A gene is a section of a DNA molecule that contains the information to code for one specific protein
Chromosomes, DNA and genes in a eukaryotic organism
Chromosomes Location in the Cell Found in the nucleus of eukaryotic organisms Found in the cytoplasm of prokaryotic organisms Purpose To instruct the cell in making proteins To transfer genetic information from one organism to its children
Chromosomes Role in Heredity Carries information about physical characteristics from parent cells to child cells
Replication DNA replication is the process in which a identical copy of DNA is formed for a new cell Two sides of a DNA molecule unwind and separate New nitrogen bases pair up with the bases on each half of the DNA forming new copies
Copy this DNA replication example into your notebook
Replication Where it occurs In the nucleus of eukaryotes In the cytoplasm of prokaryotes Purpose To prepare copies of DNA for cell reproduction Consequences of a mistake If a mistake is made in copying, a mutation can occur
Classwork 1- DNA, Genes and Chromosomes Copy the questions into your notebook (right-side) and answer them 1. is the molecule that holds genetic information 2. The structure of the double helix is two - backbones with nitrogen bases connecting them 3. The sequence of the four nitrogen bases, a, t, g and c, determines what type of will be made 4. Amino acids are the building blocks of 5. It takes a sequence of DNA nitrogen bases to determine what amino acid will be made.
Classwork 1- DNA, Genes and Chromosomes Copy the questions into your notebook (right-side) and answer them 6. A is a section of a DNA molecule that contains the information to code for one specific protein; a is made up of many of these 7. DNA is the process in which a identical copy of DNA is formed for a new cell (mitosis) 8. Chromosomes are found in the of eukaryotic organisms and the of prokaryotic organisms 9. The length of human DNA is more than 1.5 10. One strand of DNA has the sequence TGGTCGAAC. What is the sequence of the opposite strand?