What is Genetics?

Traits I have: 1. Widows peak or no widow peak 2. Eye Color 3. Hair color 4. Hair texture- wavy, straight, thick, thin 5. Hitch-hikers thumb or no hitch-hiker thumb 6. Left handed or right handed 7. Attached earlobe or dangle earlobe 8. Tongue roller or no tongue roller 9. Taste PTC paper or can not taste PTC paper

Write a paragraph describing yourself to a pen pal who has never met you. Describe yourself in a way that your pen pal will recognize you. Use your physical traits to describe you!

Genetics

Is the study of how traits are inherited.

What are traits?

Physical and non physical characteristics that are pass down from the parents.

Examples:

Review

Gene- A specific location on a chromosome that controls a trait.

GENE

Father of Genetics

Gregor Mendel

Perform the 1st scientific study of how traits are passed from one generation to the next.

Austrian monk born in 1822 Took over a garden plot in his monastery. 1856- began experimenting with garden

peas. Was able to predict the outcome of the

offspring from the plants.

Peas do have traits!

Mendel looked at 7 different traits in the pea plant.

He died and was never famous until… 1900 three scientist rediscovered Mendel’s

work.

Types of traits

Dominant- the trait that seems to cover up another trait. (T)- Capital letter

Ex: Tongue roller is dominant Recessive trait- the trait that was covered up

by the dominant trait or seemed to disappear. (t)- Lower case letter

Traits

Terms to know:

Purebred or Homozygous- organism that always produces the same traits in its offspring. (RR) or (rr)

Ex: Labrador retriever

Hybrid or heterozygous- not pure. (Rr)

Are we having fun yet?

What does the letters mean?

The letters are called Alleles, they represent a trait. For ex: Y= yellow, dominant y= green, recessive Must have two alleles to represent the trait passed

from each parent. Capital letter always over-rides the lower case letter. Genotype= letters (alleles)

Review

Capital letter= dominant Lowercase letter = recessive YY- pure, homozygous and yellow Yy- heterozygous and yellow yy- homozygous and green

Practice

If (T) = tall plant and (t) = short plant Are these plants tall or short and are they

homozygous or heterozygous? 1. (Tt) = _______________ 2. (tt)= ________________ 3. (TT)= ______________ Genotypes= Alleles

Get a good look at SpongeBob, What are some of his physical traits?

More practice

Use the following table to write the physical appearance of SpongeBob’s traits:

Trait Dominant Gene

Recessive gene

Body Shape Squarepants (S)

Roundpants (s)

Body Color Yellow (Y) Blue (y)

Eye Shape Round (R) Oval (r)

Nose Style Long (L) Stubby (l)

Write the physical trait that each group of alleles represent.

1. LL = __________

2. yy= __________

3. Ss= __________

4. RR= __________

5. Rr= _____________

6. ll = _____________

7. Ss = ____________

8. Yy = ____________

1. Long nose

2. Blue body

3. Squarepants

4. Round eyes

5. Round eyes

6. Stubby nose

7. Squarepants

8. Yellow body

Which numbers have homozygous alleles?

Drawing time

Draw SpongeBilly- he has the following traits: (SS), (rr), (Ll), (YY)

More Drawing time

Draw SpongeSalley, she has the following traits: (ss), (yy), (Rr), (Ll)

What alleles would represent the following physical traits?

a) Yellow body

b) Roundpants

c) Oval eyes

d) Long nose

e) Stubby nose

f) Round eyes

g) Squarepants

h) Blue body

a) YY or Yy

b) ss

c) rr

d) LL or Ll

e) ll

f) RR or Rr

g) SS or Ss

h) yy

Which numbers have a heterozygous set of alleles?