1. Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 Mendel and His Peas Gregor Mendel: Who was he? Priest/monk and a scientist/teacher He worked in the monastery garden. Did research on pea plants 150 years ago He discovered the principles of heredity Chapter C3 + ½ each = 2 pts

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. Mendel’s Research Mendel studied only one characteristic at a time. He studied pea plants because they Grow quickly Self-pollinate have simple traits with few variations. Section 1 Mendel and His Peas Chapter C3 + 1 each = 2 pts

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. Unraveling the Mystery Mendel was careful to use plants that were true breeding for each of the traits he was studying. By doing so, he would know what to expect if his plants were to self-pollinate. Section 1 Mendel and His Peas Chapter C3

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. Pea Plant Experiments: What were his results? The trait of only ONE parent appeared in the first generation. the trait that appeared =dominant trait. The trait that seemed to disappear = recessive trait. Section 1 Mendel and His Peas Chapter C3 Mendel’s 1 st Experiments + 1 each = 3 pts

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. Mendel allowed the first- generation plants to self- pollinate. In second-generation, MOST plants had the dominant trait and some had the recessive trait. Section 1 Mendel and His Peas Chapter C3 Mendel’s 2 nd Experiments + 1 each = 2 pts

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. The ratio between dominant & recessive traits The ratio was always about 3:1 (dominant : recessive) Section 1 Mendel and His Peas Chapter C3 + 1 pts

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. What conclusions did he make? His results could only be explained if each plant had two sets of instructions for each characteristic. each parent donated one set of instructions Section 1 Mendel and His Peas Chapter C3 + 1 each = 2 pts

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. 30 Years after Mendel’s death: his research was rediscovered his work opened the door to modern genetics he is called the “Father of Genetics” Section 1 Mendel and His Peas Chapter C3 + 1 each = 3 pts

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. Biology The area of science that studies living organisms. –“bio” = life/ living –“ology” = the study of

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. Genetics The area of science that studies heredity.

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. Heredity – p. 56 The passing of traits from parents to offspring.

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. Characteristic – p. 58 A feature that has different forms in a population.

13. Characteristics vs. Traits Characteristics Traits Hair Color Blonde Brown Black

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. Traits – p. 59 A genetically determined form of a characteristic.

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. Dominant Trait-- p. 59 The trait observed in the first generation when parents that have different traits are bred.

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. Recessive Trait –p. 59 A trait that reappears in the second generation after disappearing in the first generation when parents with different traits are bred.