copyright © by holt, rinehart and winston. all rights reserved. section 1 mendel and his peas...

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 1 Mendel and His Peas

Gregor Mendel: Who was he?

•Born 1822 in Austria •Monk and a scientist/teacher•He researched in the monastery garden.•He discovered the principles of heredity

Chapter C3

+ ½ each = 2 pts


Characteristics• Mendel studied only

one characteristic at a time.

Characteristics-• seed shape• plant height• flower color

Section 1 Mendel and His PeasChapter C3

+ 1 each = 2 pts


Mix and Match

Mendel wanted to find out what would happen if he bred or crossed two plants that had different traits of a single characteristic.


+ 1 each = 1 pt


Pea Plant Experiments: What were his results?

• One trait was always present in the first generation and the other trait seemed to disappear.

•the trait that appeared =dominant trait. •The trait that seemed to disappear = recessive trait.


Mendel’s 1st Experiments + 1 each = 3 pts


• In second-generation, the recessive trait reappeared.

•MOST plants had the dominant trait.


Mendel’s 2nd Experiments

+ 1 each = 2 pts


The ratio between dominant & recessive traits

The ratio was always about 3:1(dominant : recessive)


+ 1 pt


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


+ 1 each = 2 pts


30 Years after Mendel’s death:

• his work became widely recognized

• his ideas were rediscovered

• his work opened the door to modern genetics


+ 1 each = 3 pts


Biology• The area of science that studies living

organisms.–“bio” = life/ living–“ology” = the study of


Genetics

• The area of science that studies heredity.


Heredity – p. 56

• The passing of traits from parents to offspring.


Characteristic – p. 58

• A feature that has different forms in a population.

example: hair color


Traits – p. 58

• The different forms of the feature example: brown or red hair

Characteristics vs. Traits

Characteristics

Traits Traits Traits

Hair Color

Red or Blonde

Brown

Black


Dominant Trait-- p. 59

• The trait observed in the first generation when parents that have different traits are bred.


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.

copyright © by holt, rinehart and winston. all rights reserved. section 1 mendel and his peas...

Documents