Intro to Genetics PowerPoint Notes



Intro to Genetics PowerPoint Notes

Integrated Science 2 Name: Per.

I. Early Ideas About Heredity

A. The Theory of

• Each parent contributes factors that

• Example: A short plant crossed with a tall plant would produce a medium size plant

B. Gregor Mendel

• Born in in Czech Republic

• Worked as a teacher and performed research on the

C. Genetics

• The Scientific study of _________________

D. Mendel’s Experiment

1. Procedure:

a. purebred

b. Use pea plants with for the same

▪ Traits include:

2. Results:

a. The generation had the traits of only of the parents

b. The generation’s traits did blend.

3. Conclusions:

a. Individual factors, which do not blend, control each trait of a living thing. These factors are called .

b. The different forms of a gene are called .

• For example, the gene for plant height occurs in ____ and form

c. Some alleles are , while others are .

• The effects of a dominant allele are seen even if the recessive allele is present.

• The effects of a recessive allele are only seen if a dominant allele is NOT present.

II. Using Genetic Vocabulary

A. Defining Terms:

1. is organized into . There are of chromosomes (46 total) in a human cells ( )

2. are small segments of DNA present on chromosomes that code for a particular . are found on one chromosome.

-The estimated # of genes in the human genome is between 30,000 and 35,000

3. Genes code for , ultimately resulting in the expression of (characteristics).

4. Genes come in different forms called . Alleles are either or .

5. Organisms that have two identical alleles for a particular trait are . AA, aa

6. Organisms that have two different alleles for the same trait are .Aa

7. The (genetic make-up) for a particular trait determines the (physical characteristic).

III. A Simple Example

The organisms in our fictional example have pair of chromosomes per body cell. A gene on the chromosome codes for either or flower color.

Male: Female:

Genotype:

Phenotype:

To prepare for mating, special cells called must form. The process used to make gametes is called . Gametes cells are (containing only one homologous chromosome per pair).

Male: Female:

Pollen Ovule

(sperm) (egg)

Note: In animals, 3 of the egg cells (polar bodies) will degenerate

When organisms “mate”, 1 sperm cell (or pollen grain) from dad will randomly combine with an egg cell (or ovule) from mom. These combined gametes will produce a offspring with 2 complete sets of chromosomes

In this example, all of the pollen cells contain the recessive allele (d) for flower color and the ovule cells contain the dominant allele (D) for flower color.

Male gamete: Female gamete:

Pollen (sperm) Ovule (egg)

Fertilization

Genotype:

Phenotype:

IV. Punnett Squares

A. A Punnett square is used to predict the __________________ of producing offspring with certain ____________________

V. Special Cases of Dominant and Recessive

A. Incomplete Dominance: a genetic cross where one _______________ is not completely dominant over another

• Example: Red and White flowers combine to produce _______________ flowers.

B. Codominance: a genetic cross where __________ alleles show up in the _______________________

for the organism

• Example: Red and White flowers combine to produce _____________________________

_________________ flowers

C. Multiple Alleles: ______________________ that have more than one possible _________________

• Example: the gene for ________________________________ comes in many different forms

D. Polygenic Traits: Traits that are controlled by ________________________________ genes

• Example: about ______________ different genes control human skin color

-----------------------

Disease #___

P1 (parental) Generation

P1 Generation

All offspring will be __ with _______ flowers

F1 (offspring) Generation

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download