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