Inheritance and Genetics BI 30 GB 1 Investigate

Inheritance and Genetics BI 30 -GB 1 Investigate the mechanisms and patterns of inheritance.

Indicators • a. Discuss Gregor Mendel’s importance as the “father of genetics”. (STSE, K) • b. Discuss the historical development of scientific understanding of Mendelian genetics, including the importance of statistical analysis, probability and significance. (STSE, K) • c. Distinguish among the mechanisms of inheritance (i. e. , dominant and recessive alleles, sex-linked traits, codominance, incomplete dominance and multiple alleles). (K) • d. Determine an organism’s phenotype from its genotype, and where possible, its genotype from its phenotype. (K) • e. Construct Punnett squares using P 1 genotypes (i. e. , homozygous and heterozygous) to determine genotypic and phenotypic frequencies for F 1 and F 2 generations. (S) • f. Explore patterns of inheritance by interpreting pedigrees. (K, S) • g. Explore the factors (e. g. , gene flow, genetic drift and natural selection) which influence the prevalence (i. e. , expression and frequency) of genes and alleles within a population. (K)

Gregor Mendel • Who is he?

Gregor Mendel • Who is he?

Mendel’s Process

Mendel’s Laws • Law of segregation – • Law of independent assortment – • Law of dominance –

Mendel’s Laws • Law of segregation - states that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization. • Law of independent assortment - when two or more characteristics are inherited, individual hereditary factors assort independently during gamete production, giving different traits an equal opportunity of occurring together. • Law of dominance - one of the factors for a pair of inherited traits will be dominant and the other recessive, unless both factors are recessive.

Probability and Statistical Analysis • Overlap of math and science! • Use math and likelihood of events to occur to make inferences about organisms! • Why might this not always be accurate?

Vocabulary • Heterozygous = has a genotype composed of two different alleles. • Homozygous = has a genotype composed of two of the same allele. • Allele = a copy of coding for a particular trait or gene loci (one letter). A = capital letter means dominant. a = lower case letter means recessive. Gene loci = location of coding for an organism’s genetics (DNA), typically for a specific characteristic – however, some phenotypes are coded by multiple loci. • Genotype = combination of alleles an individual possesses. • Phenotype = the visible expression of the genotype (the code means we see ____).

Vocabulary • Monohybrid Crosses (A monohybrid cross is a mating between two individuals with different alleles at one genetic locus of interest. ) • Dihybrid Crosses (A dihybrid cross is a mating between two individuals with different alleles at two genetic loci of interest. ) • Codominance – • Sex-linked – • Autosomes –

Vocabulary • Monohybrid Crosses (A monohybrid cross is a mating between two individuals with different alleles at one genetic locus of interest. ) • Dihybrid Crosses (A dihybrid cross is a mating between two individuals with different alleles at two genetic loci of interest. ) • Codominance – when two alleles are both represented in a phenotype. • Sex-linked – chromosomes/genes that are located on X or Y chromosome. • Autosomes – non-sex-linked chromosomes.

Vocabulary • Incomplete dominance – • Multiple alleles – • Polygenic inheritance -

Vocabulary • Incomplete dominance – one trait isn’t completely dominant over the other so you get a mixed phenotype. • Multiple alleles - we end up with two alleles for every trait in our phenotype. • Polygenic inheritance - occurs when one characteristic is controlled by two or more genes.

Importance • Why is it important to know about inheritance? • Why might knowing about dominant and recessive genes be important when considering offspring? • Performing a test cross and looking at offspring can help us determine genotypes, how?

Pedigrees • Pedigrees help us establish family trees and determine potential phenotypes/genotypes of offspring. • They are useful in identifying characteristics (good or bad) that children hold and whether or not they may be genetically linked. • Functions as a record of descent. Can be animal-breed specific, or characteristic specific. • Create one using hair colour including one side of your grandparents (ie. Mom’s side), your parents (and their siblings)

Genes and Natural Selection Explore the factors (e. g. , gene flow, genetic drift and natural selection) which influence the prevalence (i. e. , expression and frequency) of genes and alleles within a population. (K) • How does expression/frequency of alleles connect to natural selection? • How does genetic drift/gene flow connect?

Genes and Natural Selection Explore the factors (e. g. , gene flow, genetic drift and natural selection) which influence the prevalence (i. e. , expression and frequency) of genes and alleles within a population. (K) • How does expression/frequency of alleles connect to natural selection? Favourable traits actually reproduce to get passed on in a population. • How does genetic drift/gene flow connect? Certain traits may insert themselves into the gene pool as part of the options! Redheads originated in Ireland! Now they are apart of our gene pool!

DNA and Chromosomes • a. Describe the structure and organization of chromosomes, including supercoiling of DNA. (K) • b. Investigate the importance of meiosis, including crossing-over and homologous chromosomes, in creating genetic variation in gametes. (K) • c. Explore chromosomal recombination and mutation and their implications on evolution by natural selection. (K) • d. Recognize various types of chromosomal abnormalities (e. g. , deletion, insertion, nondisjunction, inversion and translocation) and how they may lead to chromosomal disorders within a variety of plants and animals. (K) • e. Represent organisms’ genomes using karyotypes. (K, S) • f. Identify the haploid, diploid and polyploid conditions of organisms, including those conditions’ advantages and disadvantages. (K) • g. Investigate applications of and limitations to gene mapping as it pertains to single-gene and polygenic traits. (K, STSE)

DNA • Build a DNA molecule activity. • Each strand of DNA represents a chromosome! • Double-helix structure of DNA supercoils (bends and winds in many ways). This allows it to condense into a very small area.

Meiosis and Crossing Over • What is meiosis? • What are gametes? • What is crossing over? • What is non-disjunction?

Meiosis and Crossing Over • What is meiosis? Process of producing gametes! PMAT • What are gametes? Sex cells, haploid copies of our DNA (chromosomes) transferred to sperm and egg cells. • What is crossing over/recombination? exchange of genetic material between homologous chromosomes that results in recombinant chromosomes during sexual reproduction. • What is non-disjunction? is the failure of homologous chromosomes or sister chromatids to separate properly during cell division.

Karyotypes • A karyotype is…

Karyotypes • A karyotype is… is a test to identify and evaluate the size, shape, and number of chromosomes in a sample of body cells. Extra or missing chromosomes, or abnormal positions of chromosome pieces, can cause problems with a person's growth, development, and body functions.

Genetic Transmission, Expression and Storage BI 30 -GB 2 Investigate the storage, transmission, and expression of genetic information at the chromosomal level. BI 30 -GB 3 Investigate the storage, transmission, and expression of genetic information at the molecular level.

DNA • DNA: deoxyribonucleic acid • RNA: ribonucleic acid • Composed of sugar, phosphate and nitrogenous bases • Four (five) different types of bases: Thymine (Uracil for RNA), Cytosine, Adenine, Guanine

Protein Synthesis Vocab • m. RNA – messenger RNA (carries messages from nucleus) • t. RNA – transfer RNA (transfers amino acids to ribosome) • r. RNA – what ribosomes are mostly composed of – allows m. RNA to “fit” into it. • Helicase – DNA-splitting enzyme • DNA Polymerase – creates new DNA strands • RNA Polymerase – creates RNA strands (like m. RNA) • Codon – three-nucleotide “code” for a particular amino acid.

Protein Synthesis Replication Transcription Translation Replication creates new copies of DNA (perhaps to create a new cell). DNA Polymerase reads and creates a new strand of DNA from an unzipped DNA. Transcription takes the information encoded in DNA and encodes it into m. RNA, which heads out of the cell's nucleus and into the cytoplasm. During translation, the m. RNA works with a ribosome and t. RNA to synthesize proteins.

Transcription (creation of a “transcript” of DNA information) Helicase (an enzyme), unzips the DNA inside the nucleus. DNA or RNA Polymerase (other enzymes), binds to the DNA and “rides’ along it, adding complementary base pairs until it reaches a stop. This complementary new strand (for RNA Polymerase) is called m. RNA or messenger RNA and will exit the nucleus. Remember: In RNA, Thymine = Uracil (Why? It’s less energy-intensive than Thymine and makes it easier to create) The m. RNA then ventures from the nucleus to a ribosome in the cell’s cytoplasm.

Translation (translation of m. RNA into a combination of amino acids – polypeptide chain): The m. RNA meets with a corresponding ribosome and awaits a t. RNA (transfer RNA – which transfers amino acids) to bond with/complement its code (example: if the m. RNA is CAG, the t. RNA would be GUC). The code, or codon, is a sequence of three DNA or RNA nucleotides that corresponds with a specific amino acid or stop signal during protein synthesis. When bonded with the m. RNA in the ribosome, it allows a certain amino acid to be added to the chain (the amino acid provided corresponds to the code). Note: certain amino acids are considered “start codons” amino acids which will start the amino acid, and some are called “stop codons” which will end the amino acid chain.

(1) The DNA transcribes its message into m. RNA in the nucleus (2) m. RNA leaves the nucleus AU G U A UCGAUCG U DNA m. RNA (8) The released amino acids bond together to form a protein. nucleus cytoplasm AA 1 (5) The t. RNA found in the cytoplasm finds its specific amino acid (AA) AA 1 AA 2 (6) The t. RNA carries the amino acid over to the ribosome (7) The exposed codon of the t. RNA matches with exposed bases of the template, which causes the t. RNA to release the amino acid. The free t. RNA returns to get another amino acid C A U AU G t. RNA AA 4 (3) The m. RNA moves to find the appropriate ribosome. U A UCGAUCG U A U C G A C AA 1 AA 3 AA 2 A U G (9) When the protein is finished the m. RNA and ribosome disassemble so that the ribosome is free to be a protein synthesis site again. The m. RNA may return to the nucleus to be broken apart to form more m. RNA ribosome (4) The m. RNA attaches to the ribosome to make a template

Chromosomal Abnormalities • Deletion – we lose a base pair in the chromosome/DNA code (can happen with mistakes in crossing over). • Insertion - we gain a base pair in the chromosome/DNA code (can happen with mistakes in crossing over). • Point – change in a nucleotide at a specific point on the DNA (substitution). • Frameshift – deletions that occur in an entire codon (can lead to the creation of a wrong protein). • Inversion – chromosome flips and is read in the opposite order. • Translocation – non-homologues rearrange. • Replication Slippage – when base units repeat, the polymerase can slip past it or repeat by accident.

Genetic Expression Why do certain genes activate at different times? • Environmental – • Epigenetics – • Homeobox –

Genetic Expression • Environmental – certain things in the environment can trigger certain hormones to be created which can, in turn, lead to the activation of certain genes. • Epigenetics – some genes, while present on a chromosome may not become activity, epigenetics seeks to explain why • Homeobox – sequences in genes that typically code for growth or activation of other genes, this includes activation of genes for certain anatomical developments

Importance of DNA • a. Assess the importance of the structure of the DNA molecule to its capacity for storage, transmission, and expression of genetic information. (K) • NOT DOING! b. Discuss the contributions of various scientists (e. g. , Chargaff, Franklin, Wilkins, Watson and Crick) to understanding the structure of DNA. (K, STSE) • c. Recognize various types of gene mutations (e. g. , deletion, insertion, point and frameshift) and how they may lead to genetic disorders. (K) • d. Discuss the mechanisms of DNA proofreading and repair. (K) • e. Assess the role of genetic mutation in the process of evolution. (K) • f. Explain molecular genetic processes of DNA replication and protein synthesis, including the roles of DNA, m. RNA, t. RNA and r. RNA. (K) • g. Model molecular genetic processes, including DNA replication, transcription and translation. (S) • h. Investigate factors (e. g. , environmental, epigenetic and homeobox [Hox]) that control genetic expression. (K) • i. Model or simulate the techniques (e. g. , agarose gel electrophoresis, polymerase chain reaction and DNA sequencing) used by molecular geneticists. (S, K, A, STSE) • j. Appraise the importance of understanding the structure of DNA to advances in various fields of biology. (A, K, STSE) • k. Provide examples of current and emerging biotechnologies (e. g. , recombinant DNA, genetic testing and screening, gene therapy, stem cells and cloning). (K)