Cells and Heredity

Engagement: Making Baby Faces widow's peak cleft chin dimples

What does the word " inheritance" mean to you? Why is inheritance important to you?

Offspring may have: the same physical characteristics, or traits, as their parents because genetic information (DNA) is passed from parent to offspring during sexual reproduction.

Each sex cell (egg or sperm) of the parent organism, contains 1/2 of the genetic material needed to create a new organism.

Heredity is the passing of traits from one generation to another. This is sometimes called inheritance.

Genes are: segments of DNA that determine the inheritance for a particular trait. They usually come in pairs.

Gene 1 Gene 2 If we are talking about only one of the genes, we say allele. Cel l chromosomes Chromosomes genes one copy of a gene eggsperm gene

Trait 1NumberTrait 2Number AFree ear lobesAttached ear lobes BHair on fingerNo hair CWidow's peakNo widow's peak DCurly hairStraight hair ECleft chinSmooth chin FCan roll tongueCannot roll tongue GHitchhiker's ThumbNo hitchhiker's thumb HCan taste PTCCannot taste PTC

0 Remember: Graphs are clearly labeled and have a title.

Dominant and Recessive Alleles How many different alleles do you see in the image? Alleles are different forms of the same gene - one from the mother and one from the father. If a dominant allele is inherited, the trait will ALWAYS show up in the offspring. - Represented as a capital letter A recessive allele will only show up if there is no dominant allele. - Represented by the lowercase letter.

Your genes can be expressed in different ways. Phenotype: this is what we see/observe Genotype: this is the actual combination of alleles that shows why we see what we see.

same 2 of the same size alleles 2 different size alleles different

AA ____ Bb ____ Cc ____ Dd ____ Ee ____ ff ____ GG ____ HH ____ Ii ____ Jj ____ kk ____ Ll ____ Mm ____ nn ____ OO ____ Pp ____

Purple flowers are dominant to white flowers PP ___________________________ Pp ___________________________ pp ___________________________ Brown eyes are dominant to blue eyes BB ___________________________ Bb ___________________________ bb ___________________________ Round seeds are dominant to wrinkled RR ___________________________ Rr ___________________________ rr ___________________________ Bobtails are recessive (long tails dominant) TT ___________________________ Tt ___________________________ tt ___________________________

Straight hair is dominant to curly. ____________ straight ____________ curly Pointed heads are dominant to round heads. ____________ pointed ____________ round