1. Patterns of Inheritance
AKA Genetics

2. Genetics: all the rage in bio
One of the fastest changing fields in biology
People started studying it back to ancient Greece but they were limited to PHENOTYPE: what something looks like
Due to our great new knowledge (human genome project and much more) we can now get meaningful information form the GENOTYPE: the genes/ versions that individuals contain

3. Historically it was easy to see
We all already know too…
You look like both of your parents.
Each feature is a one or the other kind of thing… not a blend
Ie. I have my dad’s eyes, my dads mouth shape and my mom’s hands.
I am a blend but my features are not
It took Gregor Mendel to start truly understanding WHY

4. Mendel changed the world with his peas
Mendel had a hypothesis that all of our features were controlled by heritable factors (genes)
He set out to prove it but needed a model organism… something that was easy to work with and showed what he needed it too
He chose the pea plant

5. Why garden peas? 1. Easy to control fertilization.
Insure self fertilization and cross fertilization
For cross he removed the stamen before the pollen was mature

6. Why garden peas?
2. Had a variety of characters to explore

7. What Mendel did…
First he let the peas self-fertilize so they would be pure
He then crossed a purple flowering plant with a white flowering plant (cross-fertilization or hybrid) This was the _________________ P (parental) generation
The progeny from that generation are F1
When the F1 are crossed… their progeny produce what is referred to as F2

8. How he did it
Started with plants that differ in only one characteristic (monohybrid cross)
Flower color (purple vs white)
The F1 progeny were all _______
Oh no! Did the white disappear?!?
Few… in the F2 generation the white reappeared in a ratio of _____ _______ to _______________
So the white was not lost just covered for a while

9. What he concluded
There are different forms of each unit that determine heritable traits (alleles)
Principle of __________: During the formation of egg and sperm the parental alleles segregate then the diploid status of the offspring is restored at fertilization
Principle of Independent assortment: Each trait is inherited _________ from _____________. They segregate on their own
Law of dominance and recessiveness: Within each pair of alleles, there is an option for a ________ (fully expressed) and ______________ (largely unexpressed) variations

10. How we can use it
First, each trait is named for the _________ version (P for purple because it is dominant) The recessive is just ______ ______ of the (p for white)
Each parent can be either homozygous (both alleles the same) or heterozygous (one dominant and one recessive)
We track their succession using a Punnett square

11. Genes v Look
The genetic makeup of an individual trait is the _________ (heterozygous, homozygous dominant, homozygous recessive)
The look of the individual is it’s __________ (purple or white)
You can use the genotype to tell the phenotype and sometimes the phenotype to tell the genotype

12. Monohybrid cross: pod color (2 generations)

13. Test Cross
If an individual is __________, it is impossible to determine its genotype (could be ___________ __________or _____________)
Use a test cross… breed it with a known ____________ ____________
What would the F1 look like if the unknown were homozygous dominant?… heterozygous?

14. Dihybrid crosses
Looks at _____ different characters… seed color and seed shape.
If they were inherited together we would see a dominant seed color/shape combo and a recessive combo
As it is the most characters exhibit _____________ ______________.

15. Dihybrid example If yellow is dominant to green and round to wrinkled
You cross a yellow round seed with a green wrinkled. What do you get?
** need a bigger Punnett square!

16. Ratios… memorize instead of huge Punnett squares!
Heterozygous dihybrid cross always yields a phenotype ratio of _:_:_:_ (dominant both: dominant one: dominant one: recessive both)
Homozygous dominant- recessive cross gives all the ______________ (phenotypically the dominant character)

17. Incomplete dominance (blend)
Not all traits are a one or the other thing
With __________ _________both alleles work together to determine the final phenotype
Take a cross for two flowers… One red (RR) and one white (WW)
With incomplete dominance the heterozygote is an ___________ between the two homozygotes
Now both the genotypic and phenotypic ratios are 1:2:1 in a heterozygote cross

18. Codominance
Each allele is __________ _________in different regions or cells
Calico cat, rone horse
Neither one is totally dominant and the two traits co-exist without bothering each other, each controlling their own area

19. Blood types are codominant
A or B or both or neither may be expressed
If you have __antigens you recognize things with ___ and fight anything with ___
If you have AB you recognize _________
If you have O you recognize no one but they don’t detect you
A donates to __
B donates to __
AB can receive from anyone but only donate to AB
O can donate to _______ but only receive O

20. Linked traits Some traits do not independently assort
We know that chromosome have loci, all the loci on the same ___________ HAVE to be inherited together (unless crossover moves them)
Genes on the same chromosome are inherited together!

21. Sex linked traits Sometimes the link is with a sex chromosome.
The __ is notorious for being linked… color blindness, hemophilia, and MANY other things in other animals
Who would be more likely to be affected? Why?

22. Sex-Linked continued
_______ are usually affected more often because they get only one X… so good gene or bad gene automatically shows up
A female has another chance for a second X to cover the bad (or just recessive trait)
Females are often ________

23. Changes in DNA during replication
Deletion: a portion is _____________
Where is the dog?  Where the dog?
____________: a portion is doubled
Where is the dog?  Where is the the dog?
__________: If a deleted piece reattaches in the wrong orientation
Where is the dog?  Where is dog?  Where is dog eht?
Translocation: removed from chromosome and added ___________ to another
Where is the dog? The dog is in the backyard.  Where is dog? The dog is in the backyard the.

24. Human Genetic Analysis
We can display human inheritance using a display called a _______.
In a pedigree, _______ are represented by ________ and females by circles .
An individual who exhibits the trait is represented by a _____ symbol.
A _____________ line between two symbols represents a mating .
The ________ are connected to each other by ___________ line above the symbols and to the ________ by _________ lines.
Roman numerals (I, II, III, etc.) symbolize generations.
Autosomal
Recessive
Autosomal dominant