Download Intro to Genetics PowerPoint - E

11-1 p. 308-312
(Note: I encourage you to read these pages in your textbook especially
if you are struggling!)
INTRODUCTION TO GENETICS
Lesson Objectives
By the end of today you should be able to…
1. Explain how genes are inherited and how we know.
What is genetics?
• Genetics is the study of how traits are passed on
from one generation to the next.
By definition genes are….
• Definition: …sequences of DNA that that codes for
proteins that determine what traits are passed
from parents to offspring.
A Quick Look into
Applying Mendel’s Principles
Pass out video clip handout!))
How are genes inherited?
It all starts with your parents
doing the…
nasty! (Fertilization)
Sperm Cell
Egg Cell
Does anyone know what sex cells are called?
•Sex cells are called gametes.
Let’s take a more in depth look at this process!
Step 1: Two parents with their own genetic code!
Genes are the genetic codes of specific traits found
on chromosomes. (Ex. Gene 1 = Eye Color Trait)
Alleles are different forms of a gene. (B=Brown Eyes
b=Blue Eyes)
Single
Chromosome
=“B”
Step 3: Fertilization! The trait
that is expressed in the
offspring depends on the
alleles that are inherited!
Gamete
Formation
Fertilization
Gamete
Formation
Definition: New
Cell
Single
Chromosome
=“b”
Pair of “Bb”
Chromosomes
Note:
B-brown eyes
b-Blue Eyes
Let’s Reflect
•In your own
words
summarize
how genes
are inherited.
Earlier this week various students
articulated that they inherited a specific
trait from their cousins, aunts, or uncles.
Raise your hand if you can relate to this
statement.
Does this idea of inheriting traits from
cousins, aunts, or uncles make sense?
(Discuss this question with your group.)
If you don’t inherit traits from these individuals what is
the source of these common traits between you and
extended family members?
now that we know where our
acquired traits are inherited from,
let’s think about how we know this?!?
Gregor Mendel made all these initial genetic discoveries working
with peas!
Gene: Plant Height
Allele: T-Tall
t – short
While Mendel’s research only explains how
some traits are inherited we can predict the
probability of traits showing up in offspring
using...…
• ...using Punnett squares and Mendel’s principle of
dominance.
– Principle of Dominance: Mendel’s second conclusion that states
that some alleles are dominate and others are recessive.
• Dominate traits mask recessive traits when a dominate allele is present.
Applying Mendel’s principles using Punnett squares, we will
determine how scientists calculate the probability of what genes
will be inherited in the next lesson!
HOMEWORK :
Choose one of the following assignments to complete using the
information in these slides! (All templates are in the
resource section of your binder!)
1. Make a Cornell Note (Including questions & a summary)
(Template on pgs.32-33)
2. Create a Concept-Map Book (Template on pg. 25)
3. Make a graphic organizer as modeled in “Graphic
Organizer 25”. (Template on pg.11)