What is Hereditary?

1. What is Hereditary?

2. Vocabulary • Hereditary: passing physical characteristics from parent to offspring • Trait: specific characteristic • Genetics: scientific study hereditary • Fertilization: new organism forms when egg, sperm cells join • Purebred: offspring many generations have same form of trait • Gene: factors control trait • Alleles: different forms genes • Dominant allele: trait always shows up in organism when allele present

3. Vocabulary • Recessive allele: hidden whenever dominant allele present • Hydrid: organism with 2 different alleles

4. Gregor Mendel • Why did different pea plants have different characteristics? • Same tall, some short • Some green seeds, some yellow seeds • Traits similar to parents

5. Experiments • pistil produces female sex cell-egg • Stamen produces pollen • Male sex cell- sperm • Egg, sperm cell join into fertilization • Pollen reaches pistil pea • Pollination • Pea plants self pollinating • Mendel crosses pollinated pea plants • Contrasting traits- short, tall

6. F1, F 2 Offspring • Purebred tall crossed with purebred short • F1- parent • F-2 fillal- daughter, son • Outcome all tall • Short trait disappear • Self pollinated • 2nd generation- ¾ tall • ¼ short

7. Other Traits • Flower color • Seed shape • Only 1 form trait 1st generation • F2 lost trait • Reappeared ¼ plants

8. Alleles • Set genetic info • Controls inheritance • Female contributes 1st trait • Male contributes 2nd trait • 1 factor masked

9. Alleles • Traits controlled by alleles inherited • Some dominant • Some recessive • Purebred tall- 2 tall • Purebred short- 2 short • F1- one short, one tall • Hybrid • All tall- short allele masked

10. Symbols alleles • Dominant- CAPITAL LETTER • Recessive- lowercase letter • T- TALL • T- short • 2 dominant- TT • Two recessive- tt • Tt- Tall- recessive trait masked