U4. HEREDITY

Section 1: Mendel and his Peas

Heredity

Heredity: The transmission of genetic characters from parents to offspring

Offspring

Offspring: the immediate descendant or descendants of a person, animal, etc; progeny

Trait and Characteristic

A characteristic is a feature that has different forms in a population. The different forms are traits

Hair Color

Black Color Blonde Color Ginger Color

True-breeding

True-breeding: A kind of breeding in which the parents with a particular traits produceoffspring only with the same traits.

Sexual Reproduction in Plants

Female (♀)

sexual organs

Male (♂)

sexual organs

Mendel’s first

crosses

The F1 generation is a combination of 2 different true-breeding plants

First generation (F1) produced only TALL plants

The second generation (F2 ) produced tall and short plants

Mendel found that the approximately 3 dominant to 1recessive ratios showed up consistently.

short trait

Tall trait

Trait and Characteristic

Vocabulary

HEREDITY

Processes by which particular

characteristics are transmitted from

parents to their offspring.

Vocabulary

OFFSPRING

The immediate descendant or

descendants of a person, animal, etc;

progeny.

Vocabulary

INHERIT

To receive (a position, attitude,

property, etc) from a predecessor

Vocabulary

TRAIT

A trait is a specific characteristic of

an organism

Time for Questions

What step did Mendel take to be

sure that his pea plants cross-

pollinated?.

Time for Questions

What step did Mendel take to be sure

that his pea plants cross-pollinated?

a. He used two white plants.

b. He removed the anthers of one plant.

c. He added anthers to both plants.

d. He used plants that were not true

breeding.

Time for Questions

The one thing that Gregor Mendel

realized could explain the results of

his experiments was that

Time for Questions

The one thing that Gregor Mendel realized could

explain the results of his experiments was that

a. the traits were appearing at random.

b. the male traits were always the dominant ones.

c. each trait had two sets of instructions, one from

each parent.

d. his important research would open the door to

modern genetic

Time for Questions

What did Mendel discover about

recessive traits

Time for Questions

What did Mendel discover about recessive traits?

a. Recessive traits reappear in the second

generation.

b. Recessive traits disappear altogether.

c. Recessive traits never appear in the second

generation.

d. Recessive traits become dominant.