Presentation on theme: "Chromosomes carry genetic information"— Presentation transcript:
1 Chromosomes carry genetic information Body cells contain two copies of each chromosome.Humans have 23 different chromosomes (46 total chromosomes).Gametes contain one copy of each chromosome.
2 Each chromosome contains many genes. Genes are made of DNA.Genes code for proteins.Different cells express different genes.
3 Different cells express different genes Red blood cells express the gene that codes for hemoglobin.Each gene codes for a different protein (one gene : one protein).
4 Humans have approximately 100,000 different genes The Human Genome Project has cataloged thousands of genes.A computer monitor displays DNA being sequenced. The four colors represent the four chemicals that make up the instructions for DNA.Source:
6 Transcription and Translation: Processes that produce proteins from genes Transcription: DNA to RNA.RNA is a nucleic acid like DNA.Nucleic acid “language” to nucleic acid language.Translation: RNA to Amino Acid.Nucleic acid “language” to amino acid “language.”Proteins are the product and proteins are traits.
7 The Genetic CodeCombinations of bases 3-letters long code for amino acids.The code is redundant but not ambiguous. (different combinations of bases code for the same amino acid)
8 DNA replication uses each strand as a template to make new strands Original molecule: two strands of DNA forming a double helix.New strands are built by complementary base pairingNew strands are identical to original strands
9 Changes in DNA: Mutations Mutations result from changes in DNA sequence.If a mutation occurs in a gene it can change the resulting proteinMost mutations are harmful.
10 A single change at the level of DNA can change protein function Sickle cell disease.Genes come in different versions. WHY?Each person has two copies of each gene. WHY?