GeneticsGeneticsApplied BiologyApplied Biology

Key ConceptsKey Concepts

• Discuss where chromosomes and Discuss where chromosomes and genes are located and what their genes are located and what their jobs arejobs are

• Explain how traits are passed from Explain how traits are passed from parents to offspringparents to offspring

• Determine Expected vs. Observed Determine Expected vs. Observed Results by using the Punnett squareResults by using the Punnett square

ChromosomesChromosomes

• Where genes are Where genes are locatedlocated

• Body Cells: pairsBody Cells: pairs

• Sex Cell: singleSex Cell: single

• Karyotype Karyotype

GenesGenes

• Small section of Small section of chromosome that chromosome that determines a determines a specific trait of an specific trait of an organism. organism.

Dominate vs. Recessive Dominate vs. Recessive

• Dominant: Keep Dominant: Keep other genes from other genes from being expressedbeing expressed

• Recessive: don’t Recessive: don’t show up if show up if dominant gene is dominant gene is expressedexpressed

Fertilization of traitsFertilization of traits

• Pure Dominant Pure Dominant FemaleFemale

• Pure Recessive Pure Recessive manman

When both parents are When both parents are heterozygous? heterozygous? • • There is a 3 out of There is a 3 out of

4 chance that the 4 chance that the offspring is going offspring is going to show the to show the dominant traitdominant trait

Test CrossTest Cross

•

Punnett SquarePunnett Square

• • An example of a An example of a monohybrid crossmonohybrid cross

• Both mother and Both mother and father are ________. father are ________.

Question? Question?

• What would be the probability that What would be the probability that lady that is heterozygous for lady that is heterozygous for attached (dominant) and free attached (dominant) and free (recessive) earlobes and a man with (recessive) earlobes and a man with free earlobes will have a child with free earlobes will have a child with attached earlobes? Free earlobes? attached earlobes? Free earlobes?

Expected Vs Observed ResultsExpected Vs Observed Results

• Punnett Square Punnett Square ResultsResults

• Shows what to Shows what to expect when the expect when the sperm and egg of sperm and egg of two parents jointwo parents join

• Traits actually seen Traits actually seen in offspring in offspring

Gregor MendelGregor Mendel

• 1865: Austrian monk 1865: Austrian monk observed and observed and recorded certain recorded certain traits about his pea traits about his pea plantsplants

• Introduced Introduced probability to probability to geneticsgenetics

• Explained dominant Explained dominant and recessive traitsand recessive traits

Mendel’s NumbersMendel’s Numbers

Pea Plant FertilizationPea Plant Fertilization