Introduction - biol11.files.wordpress.com … · Web viewEvolution:Mendelian Genetics....
Transcript of Introduction - biol11.files.wordpress.com … · Web viewEvolution:Mendelian Genetics....
Name: _______________________________________Date: ______________________________ Block: _______
Evolution:
Mendelian GeneticsINTRODUCTION
Human have observed changes in population for many centuries.
o Humans have domesticated animals and plants and have artificially selected for various
traits in our livestock and crops.
Character –
Trait –
In the 19th Century, 2 theories on how traits are passed on from one generation to the next:
1.
2.
BLENDING INHERITANCE PARTICULATE INHERITANCE
That
“_________________________________”
(genes) were found in gametes
Physical traits from both parents are -
___________________ and the offspring will
exhibit an _________________________
between the two.
That both hereditary determinants remain in
fertilized zygote.
______________________________________
will be exhibited in the offspring.
Biology 11 Enriched Mr. Lau
Name: _______________________________________Date: ______________________________ Block: _______
GREGOR MENDEL
He studied biology, physics, and mathematics
Developed the fundamental laws of heredity
o Took some ideas from blended model and particulate model
Mendel chose garden peas (Pisum sativum) as his subjects as they are
_____________________________ and their ________________________
is easily controlled.
o He controlled pollination by manually
moving pollen between plants
o Pea flowers have both male and female
sex ______________________ so Mendel
was able to developed
“________________________” plants by
self-pollination.
Mendel examined varieties of peas for inheritable
characters and traits for his study. (stem length, pod shape, seed shape, seed color, etc.)
Biology 11 Enriched Mr. Lau
Name: _______________________________________Date: ______________________________ Block: _______
In 1865, Mendel published his findings in a paper called Experiments on Plant Hybridization, which
was mostly ignored at the time due to a number of reasons.
o First, Mendel was not well known in scientific community.
o Second, his theory ran against the popular model of blended inheritance.
MENDEL’S THREE LAWS OF INHERITANCE
1.
2.
3.
MONOHYBRID CROSS
A monohybrid cross involves one (mono) character and
different (hybrid) traits.
1. Mendel crossed a
___________________________________ with 2
different traits of the same character
(in this example, ______________________)
The F1 seeds were all _______________
The _____________ flower trait failed to appear at all.
There was also no “_________________” of colors
2. Mendel then took purple flowers from the F1 generation and allowed them to self-fertilize.
3. The flowers in the F2 generation showed a ____________________ of
__________________________ flowers
Biology 11 Enriched Mr. Lau
BY CONVENTION:
The dominant trait is given a capital letter, the lowercase of that same letter is the recessive trait. DO NOT MIX LETTERS. Pick one and stick to it.
Also, some letters are better than others. Capital S looks a lot like a lowercase (s). Pick a different letter...
Okay Better(use H for hair)
Short hair = SS HHShort hair = Ss HhLong hair = ss hh
Name: _______________________________________Date: ______________________________ Block: _______
The purple trait completely masks the white trait when true-breeding plants are crossed
o the _________________ flower trait is called ______________________
o the _____________ flower trait is called _______________________.
o The Law of Dominance
When Mendel repeated the procedure but for other
characters and traits, he would observe a
____________________ ____________________ and the
____________________________________________
MENDEL’S CONCLUSION / LAW OF SEGREGATION
The _________________________________
o Mendel concluded that each _____________
must hold 1 copy of a gene and the
_____________ will hold ___________________ (1 from each parent)
Character =
traits =
BUT WHY THAT 3:1 RATIO?
An organism has 2 alleles of a gene (1 from each parent).
If both alleles are the same _______________________
If alleles are different ________________________
Let’s assign the each allele a letter/symbol.
P = purple p = white
Biology 11 Enriched Mr. Lau
Name: _______________________________________Date: ______________________________ Block: _______
Both parents are ________________________________
We can use a __________________________________ to
show us the allele combinations
All offspring in the F1 generation are:
______________________________________
In his experiment, he then crossed the F1 generation
to produce F2 generation
_____ out of 4 are purple
_____ is homozygous
_____ are heterozygous
o _____ out 4 is white
(___________________________________)
Biology 11 Enriched Mr. Lau
Generation
Genotype
Phenotype
Male Gametes
Female
Gamete
s
Male Gametes
Female
Gamete
s
Name: _______________________________________Date: ______________________________ Block: _______
WHAT IS A TEST CROSS?
Because we know wingless dragons are ____________________________, we can breed wingless
dragons with a winged dragon.
o By looking at the ratios, we can tell if the winged dragon is homozygous or heterozygous
If female dragon is _____ then _______________________________________.
If female dragon is _____ then _______________________________________.
DIHYBRID CROSS
Mendel's Law of Independent Assortment is illustrated by the _______________________________
Biology 11 Enriched Mr. Lau
D = wingedd = wingless
Male Gametes
p p
Female
Gamete
s
P
P
Male Gametes
p p
Female
Gamete
s
P
p
Name: _______________________________________Date: ______________________________ Block: _______
o The second law describes the outcome of dihybrid (two character) crosses, or hybrid crosses
involving additional characters.
A dihybrid is an individual that is a _____________________________________
(e.g., with the genotype RrYy - round seed, yellow seed).
R = round/r = bumby, Y = yellow/y = green
What are the gametes that can be produced by this individual?
The ratio that is seen is a ______________ ratio
o a total of ____________________________ are observed:
Biology 11 Enriched Mr. Lau