CST Review Genetics I.
Standards: • BI5. a. Students know the general structures and functions of DNA, RNA, and protein. • BI1. d. Students know the central dogma of molecular biology outlines the flow of information from transcription of ribonucleic acid (RNA) in the nucleus to translation of proteins on ribosomes in the cytoplasm. • BI2. a. Students know meiosis is an early step in sexual reproduction in which the pairs of chromosomes separate and segregate randomly during cell division to produce gametes containing one chromosome of each type. • BI2. b. Students know only certain cells in a multicellular organism undergo meiosis.
Standard Summaries • BI5. a. The structures and jobs of DNA, RNA, and protein. • BI1. d. The central dogma-Genetic instructions are transcribed (copied) into mRNA in the nucleus, then the genetic instructions are translated into proteins on ribosomes in the cytoplasm. • BI2. a. Meiosis produces sex cells, chromosomes pairs are separated randomly during this process, producing gametes containing one chromosome of each type (haploid). • BI2. b. Only sex cells (gametes) are produced meiosis.
Objectives: • explain the genetic factors that influence the way we look. • recognize that DNA contains the genetic information that determines the way we look. • explain the structure and function of DNA. • understand the general pathways by which ribosomes make proteins.
DNA Basics • Double helix=twisted ladder • Chromosomes=chains of DNA and proteins. • Contains your genetic info (instructions to make proteins) • Sequences of DNA=Genes • Genes=codes for proteins=instructions for traits
What is the central dogma? • The central dogma describes the flow of information from DNA to RNA to proteins.
Central Dogma-Protein Synthesis • DNA is transcribed to mRNA in the nucleus (transcription) • mRNA carries the genetic information into the cytoplasm • Proteins are assembled at the ribosomes based on the “code” carried by the mRNA (translation)
How does your DNA determine what you look like? I. Your traits are inherited from your parents. This means DNA is passed on from generation to generation in the form of chromosomes. The codes of the DNA called genes have the instructions for your traits.
DNA • DNA contains the info to make cells, and we are made of cells…then DNA determines our cellular and molecular make-up which determines what we look like.
How does your DNA determine what you look like?II. Your traits are inherited from your parents. This means DNA is passed on from generation to generation in the form of chromosomes. The codes of the DNA called genes have the instructions for your traits. You inherit one copy of each gene from each parent giving you a certain genetic make-up that determines your physical make-up.
Where does our DNA come from? • ½ your chromosomes from your momma • ½ your chromsomes from big poppa • You have 23 pairs of chromosomes (46 total)
How does the DNA get from our parents to us? • Sex cells are produced by our parents (meiosis) and then fuse together during fertilization to combine their genetic information (chromosomes). • That’s why we look like our parents, but not exactly like our parents.