The document discusses basic genetics concepts including genes, alleles, genotypes, phenotypes, dominant and recessive traits, Mendel's laws of inheritance, and using Punnett squares to determine the probability of offspring inheriting traits from parents. It defines key terms like genotype as the genetic makeup of an individual, phenotype as the observable expression of genes, and explains how dominant traits will always be expressed over recessive traits in a heterozygous individual. Dominant traits are represented by capital letters while recessive traits are lowercase. Punnett squares allow predicting the likelihood of traits being passed from parents to offspring based on the parents' genotypes.

3. #1 #2 #3 What is happening here? These are called ______ _________ #4 #5 Diploid or Haploid ? #6 Diploid or Haploid?

4. Completely Random!!!!!!

5. Genes – determine the characteristics of an organism. Alleles – alternate forms of genes Ex. Gene = seed color Green or Yellow  Alleles *Remember* Only 1 allele for each trait is passed on to the offspring from each parent!

7. The Terms… Genotype – genetic make-up of an individual Ex. T T = genotype (letter combination) Each letter is inherited from different parents. Dad Mom T T

9. Genotype Possibilities Homo zygous (purebred) An organism with genes that are alike . Ex. BB or bb Hetero zygous (hybrid) An organism with genes that are different Ex. B b

10. DOMINANT TRAITS!!! Homozygous Dominant Genotype -Both alleles are the same. -Both are capital letters. Ex. TT Heterozygous Genotype - Different alleles. Ex. T t

11. Recessive Traits recessive genotype Both alleles are the same Both represented by lower case letters Example = tt **For an organism to show a recessive phenotype, the genotype must be homozygous recessive. Example: tt = short

12. Mendel’s 1 st Law Law of Segregation Hereditary characteristics are determined by factors called genes. For each characteristic, an offspring gets 2 genes, one from each parent. The 2 genes of each pair segregate from each other and end up in separate gametes.

13. Genotype and Phenotype Letters represent traits Capital letter = dominant trait Lower case = recessive trait Ex. H E I G H T Tall = T (dominant) Short = t (recessive) TT, Tt  Tall tt  short

14. Gene Expression Phenotype Expression of an individual’s genes…what it looks like . Ex. Tall = phenotype (physical appearance)

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17. Solving Genetics Problems If you know the genotype of the parents, it is possible to predict the likelihood of an offspring inheriting a particular phenotype. - Probability – the chance that a given event will occur - Punnett Square – named for R.C. Punnett, British biologist and mathematician - Probability is shown through monohybrid crosses – genetic cross involving only 1 trait of the parents.

18. Examples Homo zygous tall plant (TT) with homo zygous short plant (tt). 100% Tt 100% Tall heterozygous tall

19. Examples… Heterozygous long hair female with homozygous short hair male (long is dominant). L l x l l 50% Ll = long hair 50% ll = short hair 1 : 1 ratio (1Ll to 1ll)