Download presentation
Presentation is loading. Please wait.
Published byPhebe Wilcox Modified over 9 years ago
1
DNA and Modern Genetics Chapter 5C
2
D eoxyribo N ucleic A cid DNA is a molecule that stores information that a cell needs to function, grow, & divide. Proteins are large molecules that are made up of chains of amino acids. Do most of the work of the cell and make up much of the structure of a cell 20 different amino acids combine to make up thousands of different proteins. DNA provides the code, or set of rules, for making proteins. **How do DNA and proteins work together??
3
Nucleotide Bases DNA is a double-stranded spiral, much like a twisted ladder. It is made up of four nucleotides: adenine (A), thymine (T), cytosine (C), and guanine (G). Adenine pairs with thymine & cytosine pairs with guanine Genes are made up of a sequence of bases at a particular location on the DNA All Tigers Can Growl
5
D eoxyribo N ucleic A cid Before a cell divides, its entire DNA is copied in a process call replication. DNA separates into 2 strands. Each strand is used as a template to produce a copy of the other strand Nucleotides in the area match up with the bases left & form 2 new strands
6
R ibo N ucleic A cid RNA, ribonucleic acid, is involved in making proteins. 3 types of RNA Messenger RNA (mRNA): carries the information from DNA to a ribosome. Ribosomal RNA (rRNA): forms the ribosome with other proteins. Transfer RNA (tRNA): carries an amino acid and matches up to a complementary mRNA at the ribosome.
7
Transcription and Translation Transcription: the process of transferring information from DNA to RNA. RNA base pairs: cytosine pairs with guanine & adenine pairs with uracil. Transcription VS. Replication Only 1 strand of DNA is transcribed, producing a single strand of RNA After transcription, RNA is released Many copies of RNA can be made from the same gene Translation: the assembly of amino acids in their proper sequence according to the mRNA template.
8
D eoxyribo N ucleic A cid 46 chromosomes contain 6 billion base pairs of DNA. 99.9% of DNA in the cells of two different humans is the same. 0.1% variation in DNA makes a unique person. Errors can occur when DNA is copied. Any change in DNA is called a mutation. This mutation can have no effect: each cell has 2 sets of DNA, even if one is mutated, the other may work fine minor effect: could affect physical appearance major effect: can cause genetic disorder A genetic disorder is a disease or condition that results from mutations that affect the normal functioning of a cell.
9
Pedigree: a diagram of family relationships that shows two or more generations
10
What can we use DNA for? Selective breeding: process of selecting and breeding parent organisms to pass on particular traits to the offspring People are not changing DNA, but causing certain alleles to become more common in a particular breed. **How does selective breeding affect the DNA of a species? Genetic Engineering: process in which a sequence of DNA of another organism is first isolated, then inserted into the DNA of another organism, changing that organisms DNA Example: plants, organic foods **What is one major difference between changing offspring through selective breeding and genetic engineering?
11
DNA Technology: DNA identification helps police establish if a criminal is guilty. Specialists can compare DNA evidence from a crime scene with DNA from a suspect to determine if the person was at the scene. Cloning is a technique that uses technology to make copies of DNA. Cloning has been used in bacteria to make proteins and drugs to fight disease. In 1996, scientists successfully cloned the first mammal, a sheep named Dolly. All of her DNA came from a single body cell. Dolly lived for 6 years. **Why might the practice of cloning raise concerns about its future use?
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.