Download Mendel 2014

Bellwork 2-13-2014
Get out a NEW bellwork sheet!
I will be stamping bellwork at the final bell
and when your are done!!
1.How much did you study for the quiz
yesterday?
2.How well do you think you did on it?
3.If you weren’t here for the quiz, how much
do you plan on studying for it?
Unit Packet
Turn in bellwork (don’t add up)
Notes on top (meiosis I and meiosis II)
– Venn diagram
Homework/worksheets/labs on bottom
– Green variation activity
– Pink meiosis packet (3 stamps)
– Green science fair worksheet *if you were
here
– Meiosis I and II sentences (handwritten)
– Orange bellwork multiple choice worksheet
– Yellow questions packet
Annoucements
Paper by the door
Group discussion
Quiz make ups
Stepping it up
Genetics Unit
Key Words– Genetics
– Trait
– Purebred
– Hybrid
– Dominant Allele
– Recessive Allele
– Gene
– Allele
– Gamete
– Chromosome
– Theory of Heredity
– Genotype
– Phenotype
– Homozygous
– Heterozygous
– Law of Segregation
– Law of Independent
Assortment
– Law of Dominance
Genetics!
Blue Jeans?
Genetics!
Gene
Simmons?
Genetics!
Gene
Wilder?
Genetics!
Genie in a
bottle?
Genetics!
Your
Genes!!!
Genetics: the study of heredity
Trait: characteristic that can be passed
down from parent to offspring
Gregor Mendel
Father of classical genetics.
Born Johan Mendel in 1822 to
peasant family in the Czech
village
Austrian monk
Gregor Mendel (1822- 1884)
Joined
Monastery
-
-Taught Physics
and natural
science
-1856 began
experiments
Gregor Mendel (1822- 1884)
“FATHER OF
GENETICS”
-Experiments unappreciated during his time,
died in 1884 due to kidney failure
“His death deprives the poor of a benefactor,
and mankind at large of a man of the noblest
character, one who was a warm friend, a
promoter of the natural sciences, and an
exemplary priest.”
Mendel wanted
to study the
mechanisms of
inheritance.
The accepted
idea at the time
was that of
Blended
inheritance.
Gregor Mendel (1822- 1884)
• Started his
studies with
garden peas,
easy to grow
and hybridize
artificially
• Looked at 7
visible features
Gregor Mendel (1822- 1884)
-Each
experiment
looked at only 1
or 2 traits
-Kept extremely
detailed records
got peas?
Gregor Mendel (1822- 1884)
Blended Inheritance
• Studied in flower petal color
The traits of the parent plants combine or
mix in the offspring
Talk to your neighbor
Talk with your
neighbor, come up
with an example of
blended
inheritance (any
organism) and be
ready to share.
A Zorse
Mendel’s Experiments
Purebred= when two individuals of the same
breed (similar genetic traits) produce
offspring.
Hybrid=when two individuals of genetically
different breeds or species produce offspring
with a mix of traits.
Why Peas?
Mendel used peas to study
inheritance because:
1. Peas were available
2. Peas are easy to grow
3. Easily Observable Traits
Why Peas?
4. Pea flowers are constructed in such a
way that they typically self fertilized
(pollen and ova are both produced on
the same organism)
Anthers
Pea flower
Stigma
Why Peas?
By removing the anthers of one flower
and artificially pollinating using a
brush, crosses can be easily
controlled in peas.
..
.........
Bellwork 2-14-2014
Bellwork will be stamped at the final bell
and when you are done!!!
What plant did Mendel work with?
Why did Mendel work with them—4
reasons?
Announcements
Pass back unit packets
Many of you did not turn one in, or
bellwork!
Check grades – get in missing work now
and don’t fall behind!
Mendel’s Experiments
P (parental) generation=
=F1 (first filial) generation
F2 (second filial) generation=
Write down the P, F1, and
F2 in your family.
P=
F1 =
F2 =
Closure questions
Write two questions on the left hand
column of your notes about the information
we learned today.
Questions should allow you to quiz
yourself on the information from the notes.
Mendel Activity
You and a partner
will need 5 green
beads and 5 yellow
beads.
Follow the
instructions on the
sheet closely and
we will stop and
discuss at step 4
We will continue on
at step 5 as a
group
This will be
stamped when you
are done
Ratios
Look at your worksheet from yesterday…
In number 6 you crossed the F1
generation to make F2 offspring.
How many of them were yellow?
How many were green (remember the rule
for which color shows over the other)?
What is the ratio of yellow to green?
Results from crossing purple
flowered peas with white flowered
peas:
In the first filial (F1) generation all
offspring produced purple flowers
In the second generation (F2):
–705 purple
–224 white
Approximately a 3:1 ratio of purple to
white
Question
Are the F1
generation
pure bred
plants or
hybrids? How
did you
know?
This is exactly what you did in
#6 on the activity!
Interpreting Mendel’s Results
Because the F1 generation
did not produce light purple
flowers and because white
flowers showed up in the F2
generation, Mendel disproved
blended inheritance.
Some vocab…
1)GENES: section of a chromosome
that code for a trait
2)ALLELES: forms of a gene.
Ex: for eye color, blue is one allele,
brown is another allele
Chromosome from Male (dad)
Chromosomes from Female (mom)
Phenotype vs. Genotype
Phenotype – what you see!
– The physical manifestation of the trait or of
your genes
Genotype – what the genes say
– The combination of alleles in your DNA
– This is what determines the phenotype
Types of Alleles
A.Dominant a trait that is
expressed. (R)
B. Recessive- a trait that is
not expressed in the
presence of the dominant
allele – does nothing. (r)
Dominant vs. Recessive
Write out all of the combinations of the trait
for eye color assuming the brown allele is
dominant (B) and blue allele is recessive (b)
Then write what color each would be based
on the rules of dominant vs. recessive.
BB = Brown
Bb = Brown
bb = Blonde
Can you Roll your Tongue?
If you cannot roll your tongue you are
rr for tongue rolling
Bent little finger: bending inwards towards ring finger is dominant
Tongue rolling--ability to roll is dominant
Widow's peak--v-shaped hairline (think Paul Ryan). Means you are
Devil's spawn, is dominant
Dimpled chin--Dominant to have the dimple
Free earlobe: port is detached. Detached = dominant
Swing hands, clasp together. If left thumb over right, you've got the
dominant trait
Bending your thumb away from your palm: INability to bend tip 60
degrees relative to thumb is dominant
Hair on middle joint of finger is dominant
Dimpled cheeks is dominant
Ability to raise eyebrows is dominant
Ability to wiggle ears is dominant
second toe longer than big toe? Dominant
Curly hair dominant to straight
Freckles is dominant
In Mendel’s work with color in pea
plants….
What was the Dominant
allele?
What was the recessive allele?
Recessive vs. Dominant
In the F1 generation, the white
allele was hidden by the purple
“dominant” allele
In the F2 generation, 1/4 of the
offspring wound up with two
copies of the recessive white
allele thus they were white
Example
Do you have a widows peak?
If you have a widows peak you are Rr or
RR
Define the following
Dominant
Recessive
Hybrid
Use YOUR NOTES!
Mendel’s Law of Dominance
-the dominant trait is expressed and
the recessive is hidden
--what is the physical expression of
genes called?
-Phenotype!
-What is the genetic makeup called?
--Genotype!
Mendel’s Law of Segregation
-different versions of genes
(alleles) account for variations in
inherited characteristics
-An organism inherits 2 genes
(one from each parent) for every
characteristic
--a gamete (sperm or egg) carries
one allele for a trait
--if the 2 genes differ in the
offspring, the dominant one is
expressed
Homozygous- 2 alleles for a
particular trait are identical.
GG,SS,ss, gg, TT,tt
Heterozygous- two alleles
for a particular trait are
different. Gg,Ss,Tt, Yy
Question
Can you always know if you are
Heterozygous or Homozygous for a
particular trait? How?
Bellwork 2-17-2014
In the first cross both parents were
Homozygous for either white or purple
flowers
BB
bb
Parents (P)
What are the genotypes of all of the offspring?
Both parents
(F1) are
Heterozygous
for the trait of
color
F2 generation
Both parents are heterozygous
for yellow-pea allele (Yy)
Parent 1
Y
Parent 2
Y
Yy
y
Yy
y
Fill in the grid
Parent 1
Yy
Parent 2
Yy
y
Y
Y YY
Yy
y Yy
yy
Fill in the offspring
Parent
1
Yy
Y
Y
Parent
2
Yy
y
y
Punnett Squares
A blue-eyed mother mates with a
homozygous, brown-eyed father. What ratio
of brown-eyed to blue-eyed children will they
have?
Brown (B) =dominant; Blue= b
B
B
b
Bb
Bb
b
Bb
Bb
Mendel’s Results
Trait
F1 Results F2 Results
Dominent traits
round/wrinkled All Round
5,474
Round
1,850 wrinkled
mask
recessive
yellow/green All Yellow
6,022 Yellow 2,001 green
traits
full/constricted All Full
882 Full
299 constricted
Masked recessive
Pods
traits reappear
Seeds
green/yellow
axial/terminal
All Green
All Axial
428 Green
651 Axial
152 yellow
207 terminal
violet/white
All Violet
705 Violet
224 white
Tall/dwarf
All Tall
787 Tall
277 dwarf
Flowers
Stem
Mendel’s Results
F2 Results
F2 Ratios
Seeds
Seeds
5,474 Round 1,850 wrinkled 2.96:1 Round:wrinkled
6,022 Yellow 2,001 green
3.01:1 Yellow :green
882 Full
299 constricted 2.95:1 Full:constricted
Pods
428 Green
651 Axial
Pods
152 yellow
207 terminal
Flowers
705 Violet
Flowers
224 white
Stem
787 Tall
2.82:1 Green:yellow
3.14:1 Axial:terminal
3.15:1 Violet:white
Stem
277 dwarf
2.84:1 Tall:dwarf
Data and Conclusions
Ratios are not exactly 3:1
How do we decide if the ratios
are close enough to 3:1 to
support and not reject our
theory?
Mendel also looked at dihybrid
crosses
Dihybrid cross - a cross
between two parents that
differ by two pairs of alleles
(AABB x aabb)
Independent Assortment
When Mendel crossed peas and
looked at two different traits, he
discovered that the traits assorted
independently
In other words, if he was looking at
the texture of the pea and the color of
the pea. Four combinations were
possible.
Bellwork
For the trait interlaced fingers record your
phenoytpe and possible gentoype(s).
– Fold your hands and look at the thumb that is
on top.
Dominant- (G) left thumb over right
Recessive- (g) right thumb over left
Bellwork 11/18/11
Take out lab write-up from yesterday –
make sure you have answered ALL 3
questions, especially the last one:
3. What are some of the ethical issues in this
type of testing?
What does homozygous mean? Write the
genotype of a homozygous dominant trait.
What does Heterozygous mean? Write the
genotype of a heterozygous individual.
Law of Independent Assortment
As long as genes are on different
chromosomes, they will assort
independently Oh look Meiosis – Coming
next semester!
Independent
Assortment
Chromosomes
from any parent
have a 50/50
chance of lining
up on any side.
This increases
the variation in
the gametes.
Mom gives one
and Dad give
the other
chromatid.
Predicting Traits
Punnett Square- a square used to
show all the possible combinations of
gametes.
Pedigree Test- a test in which you
look at the offspring of parents to
determine the genotypes of the
parents.
Pedigree Test
Pedigree- a chart that shows how a
trait and the genes that control it are
inherited within a family
An individual that carries a particular
trait that is not expressed (recessive) is
called a carrier.
Cont.
The squares are for males and
the circles are for females
Half a square or circle filled in
means the person is a carrier of
a trait.
Interpreting Mendel’s Results
Gametes F1 Generation
from the P
generation
C C
c Cc Cc
c Cc Cc
Heterozygous parents
make gametes either
one or the other allele
Homozygous
parents can only
make gametes Fwith
2 Generation
one type of allele
The F1 Generation
is all heterozygous
C
C
c
CC Cc
c Cc cc
Chromosomes History:
The Physical Basis of Inheritance
1866 Mendel published his work
1875 Mitosis was first described
1890s Meiosis was described
1900 Mendel's work was rediscovered
1902 Sutton and Boveri noted parallels
between behavior of chromosomes
and alleles.
Bellwork
Review – What is haploid and what is
diploid?
What is the normal diploid number for
humans?
What is genotype and what is
phenotype?
Karyotyping Lab
karyotype (kr--tp) Noun An organized visual
profile of the chromosomes in the nucleus of a
body cell of an organism.
Karyotypes are prepared using cells in the
metaphase stage of cell division, when
chromosomal strands have coiled together and
duplicated, rendering them easily visible under a
microscope after staining.
Karyotyping Lab (con’t.)
Photomicrographs of the stained
chromosomes are then arranged in a
standard format according to size, the
relative position of the centromere, and
other criteria. The normal human
karyotype consists of 46 chromosomes.
Verb To prepare the karyotype of an
organism.
Karyotyping Lab (con’t.)
Bellwork
What is a karyotype?
List two things you learned in yesterday’s
lab?
What is an allele?
Define homozygous and heterozygous?
– Write an example of each, if P = purple
flowers and p = white.
Karyotyping Lab (con’t.)
Procedures
– READ Instructions and Background Info
Keep color-coded pieces separate
– Karyotype each individual (x3)
What is your diagnosis (what condition, if any,
does the patient have)? (x3)
– Answer questions in handout
– Answer Closure Questions
Karyotyping Lab Closure
Answer using complete sentences
– What did you observe about the 23 different
pairs of chromosomes found in humans?
Where they difficult to sort into pairs or not?
– Using your knowledge of gene expression
(dominant and recessive, etc.) why do you
think that individuals with these karyotypes
have abnormalities (are different from
normal)?