Download Intro to Genetics PowerPoint Notes

Disease #___
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

Worked as a teacher and performed research on the
in Czech Republic
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
b. The
generation’s traits did
of the parents
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
c. Some alleles are
____
and
form
, 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
chromosomes (46 total) in a human cells (
2.
of
)
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
or
. Alleles are either
.
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
7. The
.Aa
(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.
P1 (parental) Generation
Male:
Female:
Genotype:
Phenotype:
To prepare for mating, special cells called
. Gametes cells are
must form. The process used to make gametes is called
(containing only one homologous chromosome per pair).
P1 Generation
Male:
Female:
Pollen
(sperm)
Ovule
(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:
Pollen (sperm)
Female gamete:
Ovule (egg)
F1 (offspring) Generation
Genotype:
Fertilization
All offspring will be __
with _______ flowers
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