Download Genetics Packet 2017

Genetics
1
Goals
My goal for this packet is……..
______________________________________________
______________________________________________
______________________________________________
__________________________________________
This is my goal because……….
______________________________________________
______________________________________________
______________________________________________
______________
I know I have accomplished this goal when….
______________________________________________
______________________________________________
______________________________________________
______________________________________________
21
2
Genetics: Vocabulary
Trait- The characteristics of an organism
Genetics- The study of heredity
Heredity- The passing on of traits from an organism to its offspring
Gene- Basic unit of heredity
Dominant- Stronger trait in genetics
Recessive- Weaker trait in genetics
Hybrid- Organism with two different genes for a particular trait
Pure-bred- Organism that has genes that are alike for a particular trait
Incomplete dominance- Gene pairs that are not dominant or recessive. Neither
gene in a gene pair masks the other.
Law of segregation- Gene pairs separate during the sex cell formation.
Law of independent assortment- Each gene pair for a trait is inherited
independently of the gene pairs of all other traits.
Phenotype- The visible characteristics of an organism
Genotype- The actual gene makeup of an organism
Probability- The possibility, or likelihood that a particular event takes place.
Chromosome- Rod shaped structure that directs the activities of the cell and
passes on the traits of a cell to new cells.
3
Chromosome theory- Theory that states that genes are found on chromosomes
and that genes are carried from the parental generation to the next generation on
chromosomes.
DNA- ( deoxyribonucleic acid) Nucleic acid that stores the information needed to
build proteins and carries genetic information about an organism.
Allele- Each form of a gene
Multiple Allele- More than two alleles that combine to determine a certain
characteristic.
Sex-linked Trait- Characteristics passed from parent to child on a sex
chromosome.
Nondisjunction- The failure of chromosomes to separate from each other during
cell division.
Nitrogen Bases- The 4 Nitrogen bases that make up a DNA molecule are adenine,
thymine, guanine, and cytosine. A-T, GC
Additional Notes
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
4
1.
2.
3.
4.
5.
Chapter 23, Section 23-1 ( pg. 584-592)
________________ was the Austrian monk that worked with pea plants
and is considered the “ father” of genetics.
Another word for characteristics of an organism is _______________.
________________ is the study of heredity.
________________ is the passing on of traits from an organism to its
offspring.
Why did Mendel choose pea plants? ( pg. 584, 3rd & 4th paragraph)
6. ____________ are the basic unit of heredity
7. _____________ are characteristics of an organism
8. The “stronger” trait is said to be the _________________ trait.
9. The “weaker” trait is said to be the ____________________ trait.
10.________________ are scientists who study heredity.
11.Organisms that have genes that are alike for a particular trait are called
______________________.
12.Organisms that have genes that are different for a particular trait are called
_________________.
13.What is the Law of segregation? ( pg. 590)
14.What is the Law of independent assortment? ( pg. 590)
15.List the 6 principles of genetics.
5
Chapter 23, Section 23-5 (pg.602-608)
1. What is an Allele?
2. What does multiple alleles mean?
3. What are the 4 major blood types? ( pg.603)
4. What two blood types are dominant?
5. What does codominant mean? ( pg.603)
6. What blood type is recessive? ( pg.603)
7. Pg. 604 paragraph summaries, Paragraph #1
_____________________________________________________________
8. Pg. 604 paragraph summaries, Paragraph #2
_____________________________________________________________
9. Pg. 604-605 paragraph summaries, Paragraph #3
_____________________________________________________________
10. What does XX mean in human genetics? ( pg. 605)
11. What does XY mean in human genetics? ( pg. 605)
12.What are sex-linked traits? (Pg. 606)
13.What is hemophilia? ( pg. 606)
6
14. Paragraph summary, Pg. 607 paragraph #1
_____________________________________________________________
15.The failure of chromosomes to separate from each other during meosis is
known as __________________________. ( pg. 607)
16.Usually people have _______ chromosomes. (pg. 607)
17.When a person has an extra chromosome on the _________ pair the
condition known as ________________________ results. (pg. 608)
18.Paragraph summary, Pg. 608 paragraph #2
____________________________________________________________
7
Cloning
What is cloning? Are there different types of cloning? Does cloning involve all types of animals?
These are some of the basic questions asked by students as we start to talk about cloning. A basic
understanding of the different types of cloning is key to making an informed stance on the current
issues surrounding cloning.
The following are three of the types of cloning being most discussed in the media today: (1)
recombinant DNA technology or DNA cloning, (2) reproductive cloning, and (3) therapeutic cloning.
The terms “recombinant DNA technology,” “DNA cloning,” “molecular cloning” or “gene
cloning” all refer to the same process: the transfer of a DNA fragment from the cell of one organism
to another cellular organism. This cell is typically a bacterial plasmid. This cell will then divide and
the DNA will be reproduced in this new cell. Scientists studying a particular gene often use
bacterial plasmids to generate multiple copies of the same gene. Scientists then use this
“recombinant DNA molecule” for study.
Reproductive cloning is a technology used to generate an animal that has the same
nuclear DNA as another currently or previously existing animal. Dolly (the sheep) was created by
reproductive cloning technology. In a process called “somatic cell nuclear transfer” (SCNT)
scientists transfer genetic material from the nucleus of a donor adult cell to an egg cell whose
nucleus, and its genetic material, has been removed. The reconstructed egg containing the DNA
from a donor cell must be treated with chemicals or an electric current in order to stimulate cell
division. Once the cloned embryo has reached a suitable size it is transferred to the uterus of a
female host where it continues to grow until birth.
Dolly’s success was an important step because it proved that the genetic material from a
specialized adult cell, such as an udder cell programmed to express only those genes needed by
udder cells, could be programmed to generate an entire new organism. Before this demonstration,
scientists believed that once a cell became specialized as a liver, heart, udder, bone, or any other
type of cell, the change was permanent and other unneeded genes in the cell would become
inactive. Some scientists believe that errors or incompleteness in the reprogramming process
cause the high rates of death, deformity, and disability observed among animal clones.
Therapeutic cloning, also called “embryo cloning,” is the production of human embryos for the
use in research. The goal of this process is not to create cloned human beings, but rather to
harvest stem cells that can be used to study human development and to treat disease. Stem cells
are important to biomedical researchers because they can be used to generate virtually any type of
specialized cell in the human body. Stem cells are extracted from the egg after it has divided for 5
days. The egg at this stage is called a blastocyst. The extraction process destroys the embryo,
which raises a variety of ethical concerns. Many researchers hope that one-day stem cells can be
used to serve as replacement cells to treat heart disease, Alzheimer’s, cancer, and other diseases.
One big question that scientists are asked is how can we use cloning technologies to benefit
humans? Recombinant DNA technology is important for learning about other related
technologies, such as gene therapy, genetic engineering of organisms, and sequencing genomes.
Gene therapy can be used to treat certain genetic conditions by introducing corrected copies of
faulty genes into the cells of host organisms. Genes from different organisms that improve taste
8
and nutritional value or provide resistance to particular types of disease can be used to genetically
engineer food crops.
If the low success rates can be improved ( Dolly was only one success out of 276 tries ),
reproductive cloning can be used to develop efficient ways to reliably reproduce animals with
special qualities. For example, drug producing animals or animals that have been genetically
altered to serve as models for studying human disease could be mass-produced. Reproductive
coning also could be used to repopulate endangered animals or animals that are difficult to breed.
Cloning extinct animals presents a much greater challenge to scientists because the egg and
surrogate needed to create the cloned embryo would be of a different species from the clone.
Therapeutic cloning technology may some day be used in humans to produce whole organs
from single cells or to produce healthy cells that can replace damaged cells in degenerative
diseases such as Alzheimer’s or Parkinson’s. This technology still needs to be developed before it
can become a realistic option for treatment of disorders.
As with most new medical advances there are risks. Reproductive cloning is expensive and
highly inefficient. More that 90% of cloning attempts fail to produce a viable offspring. More than
100 transfers of genetic material could be required to produce one viable clone. In addition to low
success rates, cloned animals tend to have a more compromised immune system, higher rates of
infection, tumor growth, and other disorders.
All of this information leads to an obvious question, “Should humans be cloned?” Physicians
from the American Medical Association and scientists with the American Association for the
Advancement of Science have issued formal public statements advising against human cloning.
Currently, the US congress is considering passage of legislation that could ban human cloning in
the United States. Due to the inefficiency of animal cloning ( only about 1 or 2 viable offspring for
every 100 experiments ) and the lack of understanding about reproductive cloning, many scientists
strongly believe that it would be unethical to attempt to clone humans. Not only do most attempts to
clone mammals fail, about 30% of clones born alive are affected with “large offspring syndrome”
and other debilitating conditions. Several cloned animals have died prematurely from infections or
other complications. The same problems would be expected in human cloning. In addition,
scientists do not know how cloning could impact mental development. While factors such as
intelligence and mood may not be as important in a mouse or a cow, they are crucial for the
development of healthy humans. With so many unknowns concerning reproductive cloning, some
feel that any attempt to clone humans with the current technologies is potentially dangerous and
ethically irresponsible.
9
Cloning Questions
1. What are the three types of cloning mostly discussed in modern media?
2. What is recombinant DNA cloning, and what process does it refer to?
3. What is SCNT?
4. Why was Dolly’s success special?
5. What is the purpose of therapeutic cloning?
6. What are some ways reproductive cloning could be used?
7. What are some drawbacks of reproductive cloning?
10
8. What two organizations have issued statements against human cloning?
9. Why do they feel it is unethical?
10.What do you think? Should humans be cloned? Why do you feel this way?
11
The Basics of Cloning
Please go to the following website to begin:
http://learn.genetics.utah.edu/content/cloning/
Part 1 “ What is cloning?”
1. _________________ is the creation of an organism that is an exact
copy of another.
2. You might not believe it, but there are human clones among us right
now. They weren’t made in a lab, though they’re
__________________, created naturally.
3. _________________________ is the relatively low-tech version of
cloning. As the name suggest, this technology mimics the natural
process of creating identical twins.
4. Artificial embryo twinning uses the same approach, but it occurs in a
______________ instead of in the mothers body.
5. Somatic cell nuclear transfer was the method used to create
_________________.
6. A _______________ is any cell in the body other than the two types
of reproductive cells, sperm and egg.
7. It’s the difference in our _________ that make each of us unique.
8. To make Dolly, researchers isolated a ________________ from an
adult female sheep. Next they _______________ the
_______________ from that cell to an egg cell from which the
nucleus had been removed. After a couple of tweeks, the egg cell,
with it’s new nucleus, was behaving just like a freshly fertilized
______________. It developed into an _______________, which
was implanted into a ________________ and carried to term.
9. ______________ ( be Specific! I need the name of the mammal!)
was the first ever mammal to be cloned from an adult somatic cell.
12
10.
Play the natural reproduction movie ( it’s the movie with the
sheep) for this question. Because the offspring contains a
combination of the two sets of parent’s chromosomes, it is not
identical to either parent but it is, instead,
________________________.
11.
Play the somatic cell transfer movie ( still the sheep) for the
following questions: The somatic cell is _______________ in a media
that causes it to ___________________ as an udder cell.
12.
An egg cell is ________________ from a different animal cell.
The egg cell’s ________________ is removed.
13.
The egg cell and the somatic cell are _______________ using
an ____________________.
Part 2 “Click and Clone”
14. List all 6 steps in the “click and clone” procedures.
1. Isolate donor cell from ____________& ________________
2. __________and _________the nucleus from the ______ cell.
3. Transfer _______ cell nucleus into _______ ________ cell.
4. ____________ cell division.
5. ___________ the embryo in ___________ the surrogate mother.
6. Deliver the baby mouse clone to _____________________
15. What color is the cloned mouse? ________________________
16. In the real mouse cloning experiment, what was the name of the first
born survivor? ___________________________
13
Part 3 The History of Cloning
17. What was the first organism ever cloned using artificial embryo
twinning? ___________________________________________
18. How did Hans Sermann separate cells from a salamander embryo?
_______________________________
19. What happened to the tadpoles that were cloned from more
advanced embryos? ______________________________
20. Where did John Gurdon obtain cells for his cloned frogs?
_________________________________
21. What was the first mammal embryo cloned?
________________________________
22. What were the names of the two cloned
calves?____________________________________
23. Cultured sheep’s cells were used to create two lambs named
_______________________ and ____________________
24. What was the first mammal created using somatic cell nuclear
transfer? _________________________
Where did the DNA come from for this clone?
______________________
25. Out of 29 primate clones attempted, how many were born?
_______
26. How was the clone "Polly" different from the first sheep clone
named "Dolly?" __________________________
27. What was the first extinct animal cloned?
____________________________________
14
Part 4 “ Is it Cloning or NOT”
28. For each of the following scenarios, indicate YES (it is cloning) or
NO (it is not cloning)
___________Sperm taken from a male goat is combined with a
female's egg in a petri dish. The resulting embryo is implanted into
the female's uterus to develop
___________A sheep embryo, composed of 16 cells, is removed from
the mother's uterus and separated into indivudal cells. Each cell is
allowed to multiply, creating 16 separate embryos, which are then
implanted in different female sheep to develop to maturity.
___________A cow with many desirable traits is stimulated with
hormones to produce a number of egg cells. Each of these eggs is
fertilized and implanted into a surrogate mother.
___________ In vitro fertilization
___________ Cell nuclei from an extinct woolly mammoth are placed
into enucleated cow cells.
Part 5 “ Why Clone”
29. List three medical purposes for cloning research.
1. Cloning animal models of ________________
2. Cloning _________ ___________ for research.
3. Pharming for _____________ _______________
30. In theory what two things do we need to clone extinct animals?
1. A well-preserved source of _____________
15
2. Closely related _____________, currently _____________ that
Could serve as a ____________ mother.
31. Is cloning of extinct dinosaurs possible? Why or why not?
Should we attempt this? Why or why not? ( This is an opinion
question. You can’t be wrong, but you must have an opinion ).
32. List two reasons for the cloning of humans.
1. To help __________ ___________ have children.
2. To replace a _____________ child.
33. In your opinion, should we allow the cloning of humans? Why
or why not?( You must have an opinion).
Part 6 “Cloning Myths”
34. What are two common misconceptions about cloning?
1. __________________________________________
2. ___________________________________________
35. Why don’t we have “instant “clones?
36. Would your clone be a “carbon copy” of you? Why or why not?
16
Genetic Disorders
What are Genetic disorders
Please go to the following website to begin:
http://learn.genetics.utah.edu/content/disorders/
Part 1 Single Gene
1. What are single gene genetic disorders?
2. List 2 different single gene genetic disorders.
3. Answer the following questions For one of your listed disorders.
a. What is the disorder?
__________________________________________________
b. What part of the body does it effect?
__________________________________________________
c. How do people get the disorder?
__________________________________________________
d. What are the symptoms?
__________________________________________________
e. How is it treated?
__________________________________________________
Part 2 Chromosomal Abnormalities
1. What are chromosomal genetic disorders?
2. List two chromosomal genetic disorders
17
3. Answer the following questions For one of your listed disorders.
f. What is the disorder?
__________________________________________________
g. What part of the body does it effect?
__________________________________________________
h. How do people get the disorder?
__________________________________________________
i. What are the symptoms?
__________________________________________________
j. How is it treated?
__________________________________________________
Part 3 Multifactorial Disorders
1. What are multifactor genetic disorders?
2. List one multifactor genetic disorder. __________________________
3. Answer the following questions For one of your listed disorders.
k. What is the disorder?
__________________________________________________
l. What part of the body does it effect?
__________________________________________________
m. How do people get the disorder?
__________________________________________________
n. What are the symptoms?
__________________________________________________
o. How is it treated?
_________________________________________________
18
DNA Extraction: Biotechniques Virtual Labs
Go to: http://learn.genetics.utah.edu/content/labs/extraction/
1.
What are five reasons we need to extract and isolate DNA?
a. __________ b. ___________ c. __________ d. _________ e. __________
2.
What is needed as a source of DNA?______
3.
List the four steps to purifying DNA from a cheek swab
a. __________________________
b.
_____________________________
c. __________________________
_____________________________
d.
4. What is the buccal swab used for?
__________________________________________
5.
What two ingredients are in the lysis solution and what does each do?
Contains: ____________ does
____________________________________________
Contains: ____________ does
____________________________________________
6. How does the warm water bath help the? It does not say but what do you think?
___________________________________________________________________
7. What does the concentrated salt solution do?
___________________________________________________________________
8. Why is Centrifuging done?
___________________________________________________________________
9. What does the isopropyl alcohol do?
___________________________________________________________________
10. What is the reason for the second centrifuging?
___________________________________________________________________
Click on “How to extract DNA from anything living”
11. What are four suggested material to use? a. ________ b. ________c. _______d.
________
12. Name three sources you should not use. a. ___________b. _________c. _______
13. What does blending accomplish?
_________________________________________
19
14. What four things happen in the second step? a. _________-_____
b. _____________
c. _________________ d.
______________________
15. Click on the “Why am I adding detergent?” What two sacs are broken
open? _________
________ and how does a detergent break them open
__________________________
_______________________ and what is released _________?
16. What happens in step three? __________________________
17. Click on “Why did I add meat tenderizer? In this experiment,
___________ acts as an enzyme to cut
________ just like a pair of scissors. The _______ in the nucleus is
molded, folded, and
protected by _______. The ____________ cuts the proteins away
from the DNA.
18. What happens in the fourth step?
__________________________________________
19. Describe how the alcohol is added into the tube?
______________________________
Why is it done in this manner?
____________________________________________
20. DNA will begin to come out of solution where in the test tube?
____________________
21. What is the wooden stick or hook used for?
__________________________________
21. What is the long stringy stuff in the test tube? __ __ __
20
DNA Extraction Lab
Materials:
Raw wheat germ
Alcohol
50-60°C water
Wood tool block
Liquid detergent
Paper towels
Test tube brush
2 Test tubes
Stirrer-glass rod
DNA Collector paper clip hook
Eyedropper
Measuring spoons
Instructions/Procedures
1.
Place 1 teaspoon of raw wheat germ in a clean test tube.
2.
Add 1 tablespoon of (50-60 °C) tap water and mix for 3 minutes.
3.
Add 1/4 teaspoon of detergent and mix gently every minute for 5 minutes.
Try not to create foam
4.
Use eyedropper to remove any foam from the top of the solution.
5.
Tilt the test tube at an angle. SLOWLY pour 1 tablespoon of alcohol down the side so that it forms a
layer on top of the water/wheat germ/detergent solution.
Try not mix the two layers together. DNA precipitates at the water-alcohol boundary. Therefore, it is
important to add the alcohol slowly.
6.
Let the test tube sit for a few minutes. White, stringy, DNA will appear where the water and alcohol
meet.
7.
You can get more DNA to precipitate from the solution by using the DNA-collecting tool (the paper
clip hook) to gently lift the water solution up into the alcohol.
8.
Use paper clip hook to collect the DNA.
9.
Place the DNA on a piece of paper towel. You can keep the DNA if you wish .
Clean Up of equipment:
When finished have all equipment clean and dry and stored as you found it.
Follow up questions.
1.
Where did the DNA come from? _____________________________________
2.
What did the soap do to help extract the DNA? _________________________
3.
What did the alcohol do to help extract DNA? __________________________
4.
What does “precipitate” mean in this lab? _____________________________
21
DNA - The Double Helix
Recall that the nucleus is a small spherical, dense body in a cell. It is often called the "control
center" because it controls all the activities of the cell including cell reproduction, and
heredity. Chromosomes are microscopic, threadlike strands composed of the chemical DNA
(short for deoxyribonucleic acid). In simple terms, DNA controls the production of proteins
within the cell. These proteins in turn, form the structural units of cells and control all chemical
processes within the cell. Think of proteins as the the building blocks for an organism, proteins
make up your skin, your hair, parts of individual cells. How you look is largely determined by
the proteins that are made. The proteins that are made is determined by the sequence of DNA in
the nucleus.
Chromosomes are composed of genes, which is a segment of DNA that codes for a particular
protein which in turn codes for a trait. Hence you hear it commonly referred to as the gene for
baldness or the gene for blue eyes. Meanwhile, DNA is the chemical that genes and
chromosomes are made of. DNA is called a nucleic acid because it was first found in the
nucleus. We now know that DNA is also found in organelles, the mitochrondria and
chloroplasts, though it is the DNA in the nucleus that actually controls the cell's workings.
In 1953, James Watson and Francis Crick established the structure of DNA. The shape of DNA
is a double helix (color the title black), which is like a twisted ladder. The sides of the ladder
are made of alternating sugar and phosphate molecules. The sugar is deoxyribose. Color all the
phosphates pink (one is labeled with a "p"). Color all the deoxyriboses blue (one is labeled
with a "D") .
The rungs of the ladder are pairs of 4 types of nitrogen bases. The bases are known by their
coded letters A, G, T, C. These bases always bond in a certain way. Adenine will only bond to
thymine. Guanine will only bond with cytosine. This is known as the "Base-Pair Rule". The
bases can occur in any order along a strand of DNA. The order of these bases is the code the
contains the instructions. For instance ATGCACATA would code for a different gene than
AATTACGGA. A strand of DNA contains millions of bases. (For simplicity, the image only
contains a few.)
Color the thymines orange.
Color the adenines green.
Color the guanines purple.
Color the cytosines yellow.
Note that that the bases attach to the sides of the ladder at the sugars and not the phosphate.
The DNA helix is actually made of repeating units called nucleotides. Each nucleotide consists
of three molecules: a sugar (deoxyribose), a phosphate which links the sugars together, and then
one of the four bases. Two of the bases are purines - adenine and guanine. The pyrimidines are
22
thymine and cytosine. Note that the pyrimidines are single ringed and the purines are double
ringed. Color the nucleotides using the same colors as you colored them in the double helix.
The two sides of the DNA ladder are held together loosely by hydrogen bonds. The DNA can
actually "unzip" when it needs to replicate - or make a copy of itself. DNA needs to copy itself
when a cell divides, so that the new cells each contain a copy of the DNA. Without these
instructions, the new cells wouldn't have the correct information. The hydrogen bonds are
represented by small circles. Color the hydrogen bonds grey.
The Blueprint of Life
Every cell in your body has the same "blueprint" or the same DNA. Like the blueprints of a
house tell the builders how to construct a house, the DNA "blueprint" tells the cell how to build
the organism. Yet, how can a heart be so different from a brain if all the cells contain the same
instructions? Although much work remains in genetics, it has become apparent that a cell has
the ability to turn off most genes and only work with the genes necessary to do a job. We also
know that a lot of DNA apparently is nonsense and codes for nothing. These regions of DNA
that do not code for proteins are called "introns", or sometimes "junk DNA". The sections of
DNA that do actually code from proteins are called "exons".
1. Write out the full name for DNA. _____________________________________________
2. What is a gene? _______________________________________________________
3. Where in the cell are chromosomes located? __________________________________
4. DNA can be found in what two organelles?
_________________________________________________________
5. What two scientists established the structure of DNA?
______________________________________________
6. What is the shape of DNA? ______________________________________
7. What are the sides of the DNA ladder made of?
________________________________________
8. What are the "rungs" of the DNA ladder made of?
_______________________________________________________
9. What sugar is found in DNA? _______________________ In RNA? ___________________
10. How do the bases bond together? A bonds with _____
G bonds with _______
11. DNA is made of repeating units called _______________________________________
23
DNA- The Double Helix
24
Genetics and Probability
KEY CONCEPTS
Probability can be used to
predict the results of genetic
crosses.
In addition to probability, a special
chart called a Punnett square is used
to show the possible gene
combinations in a cross between two
organisms.
Building Vocabulary Skills: Analyzing Information
A phenotype refers to ____________________________________________
A genotype refers to the __________________________________________
Using the definitions you stated, answer the questions about the
following diagram
P
F1
B
X
b
Bb
bb
BB
B
B
B
b
Bb
b
b
Bb
Bb
1.
What are the phenotypes of the parents? _________________________
2.
What are the genotypes of the parents? _________________________
3.
What are phenotype of the offspring? ___________________________
4.
What are the genotypes of the offspring? ________________________
25
F1
F2
B
X
B
BB
Bb
Bb
B
b
b
B
Bb
b
b
Bb
bb
1.
What are the phenotypes of the parents? _________________________
2.
What are the genotypes of the parents? _________________________
3.
What are phenotype of the offspring? ___________________________
4.
What are the genotypes of the offspring? ________________________
5.
How can you explain the fact that the offspring that has a BB genotype and
one that has a Bb genotype are both black?
_________________________________________________________
6.
Can a white offspring be a hybrid? Why? __________________________
_________________________________________________________
26
Genetics and Probability
What color is the pea pod?
Green ( G) is the dominant color or pods of pea plants.
Yellow (g) is recessive.
1. What are the phenotypes for the following genotypes?
a. GG ________________________________________
b. Gg ________________________________________
c. gg ________________________________________
2. Fill in the Punnett squares below to show the outcomes of the crosses. Next to
each genotype, write the correct phenotype.
A. GG x Gg
B. GG x gg
C. Gg x Gg
D. Gg x gg
27
3. Questions on the Pea Pod Punnett squares
A. In Square A, what is the probability of getting a purebred offspring?
__________
B. In square A, What is the probability of getting a GREEN pea plant?
__________
C. In square B, what is the probability of getting a purebred offspring?
__________
D. In square B, what is the probability of getting a yellow pea plant?
__________
E. In square C, what is the probability of getting a yellow pea plant?
__________
F. In square C, what is the probability of getting a hybrid green plant?
__________
G. In square D, what is the probability of getting a GREEN plant?
__________
H. In square D, what is the probability of getting a purebred GREEN plant?
__________
28
Genetics Practice Problems
1. For each genotype below, indicate whether it is Hybrid (He) or
Purebred (Ho)
AA _____
Ee ____
Ii _____
Mm _____
Bb _____
ff ____
Jj _____
nn _____
Cc _____
Gg ____
kk _____
oo _____
DD _____
HH ____
LL _____
Pp _____
2. For each of the genotypes below determine what phenotypes would be
possible.
Purple flowers are dominant to
Bobtails in cats are recessive.
white flowers.
TT _________________
PP___________________
Tt _________________
Pp___________________
tt________________
pp___________________
Round seeds are dominant to
Brown eyes are dominant to
wrinkled seeds
blue eyes
RR__________________
BB_________________
Rr__________________
Bb________________
rr __________________
bb________________
29
3. For each phenotype below, list the allele combinations which show the desired
trait (remember to use the letter of the dominant trait)
Straight hair is dominant to
curly.
Pointed heads are dominant to
round heads.
____ curly
___ rounded
_____,_____ Straight
______ _____ Pointed
4. Set up a Punnett squares for each of the crosses listed
below.
Round seeds are dominant to wrinkled seeds.
RR x rr
How many of the offspring will have round seeds?
_________________
Rr x rr
What are the phenotypes of the parents
_____________________
RR x Rr What are the phenotypes of
the offspring
_____________________
Rr x Rr
What is the genotypic Ration?____________________
Practice with Crosses. Show all work! SHOW ALL WORK
7. A heterozygous round seeded plant (Rr) is crossed with a
homozygous round seeded plant (RR).
What is the ratio for the offspring that are homozygous (RR)? __________
30
Genetics of Sex Determination
The gene which controls whether a person will be a male or a female is located on the Y
chromosome in humans. It is called SRY, which stands for sex-determining region of the Y
chromosome. If a zygote has a Y chromosome with the SRY gene, the embryo will develop
testes and male anatomy. If a zygote does not have a Y chromosome with the SRY gene,
the embryo will develop ovaries and female anatomy.
Males have an X and a Y chromosome (XY), whereas females have two X chromosomes
(XX). During meiosis (type of cell division that produces sex cells or gametes) in a female,
the two X-chromosomes separate, so each egg has a single X-chromosome. In males, even
though the X and the Y-chromosomes are very different, they can nevertheless pair with
each other and separate from each other during meiosis. This means that males produce
two kinds of sperm; half have an X chromosome and half have a Y chromosome.
1.
What will be the sex of a child produced when an egg is fertilized by a sperm that
has a Y chromosome?
________________________________________________________________________________________________
2.
What type of sperm must fertilize an egg to result in a female child?
3.
Draw a Punnett Square which shows the inheritance of the sex chromosomes.
4.
Based on this Punnett Square, what% of children would you expect to be male? ____
5.
Test this prediction, by writing down the initials of all the children your mother has
had. Arrange these initials in order from the oldest to the youngest, indicating
whether each was male or female.
5. Ex-Mr. L’s Mother
______________________
GB- female
SL-male
DL-male
6.
How many of these children were male? _________
7.
8.
7. 66.66%
What percent of your mother's children was male? ________
Now, get the number of male children and the total number of children for the
mothers of ten of your classmates, and calculate the overall percent male children.
a.
number of male children ________
b.
total number of children ________
c.
percent male children
________
31
6. Two
9.
Compare the predicted percent male with the observed percent male for your
mother’s children
Predicted: ________ Observed: ________
10.
Compare the predicted percent male with the observed percent male for all the
children of the ten mothers.
Predicted: ________ Observed: ________
11.
How similar to the prediction are the observed results?
_____________________________________________________________
12.
13.
_____________________________________________________________
Think about this
Notice that the percent male children for a given mother may vary a lot from the predicted
percent. This is due to random chance in whether a sperm with an X or Y chromosome was
involved in the fertilization which produced each child. Random chance generally averages out
in large samples. The percent male children for the ten mother group should be closer to the
prediction.
Look at your own and your classmates' lists of children's initials with the sex of each child to
answer the following questions.
a.
If a mother's first child is a son, is the next child necessarily a daughter? ____________
b.
If a mother's first child is a daughter, is the next child necessarily a son? ____________
c.
If a mother's 1st two children are sons, is the next child necessarily a daughter? ______
d.
If a mother's 1st two children are daughters, is the next child necessarily a son? _______
Can you predict the sex of the next child based on the sex of a previous child or children? ____
Explain _______________________________________________________________________
_______________________________________________________________________
32
Genetics of Albinism
Inheritance of Albinism
To learn more about how genetic traits are inherited,
we will consider a specific example -- the gene that
controls whether or not a person can produce the
pigment melanin which contributes to the color of
skin, eyes and hair. Some people have the hereditary
condition, albinism; they are not able to produce
melanin and have little or no pigment in their skin and hair. Two different versions
of the same gene are called alleles. One allele of this gene codes for melanin
production and normally pigmented skin and hair; it is symbolized by A. Another
allele of this gene codes for albinism; it is symbolized by a.
We'll analyze inheritance for the case where
each parent has one A allele and one a allele (i.e.
both parents are Aa).
1.
A
A
a
AA
Aa
What different combinations of A
a
Aa
aa
and/or a alleles would you expect to
observe in the children of these parents? _________________________
Explanation of the Punnett Square
For a hybrid mother, half of her eggs will have a chromosome which carries the A allele, and
the other half with the a allele. Similarly, half of the father's sperm will have an A allele,
and half the a allele. The squares show the possible combinations from fertilization of the
two different types of eggs by the two different types of sperm.
2.
What fraction of the couple children would you expect to be AA? ________
3.
What fraction of this couple's children would you expect to be aa? ______
Explanation of the affects of inheritance of the A versus a allele
The children who have AA alleles will have normal pigmentation, and the children who
have aa alleles will have albinism. The next question is:
4.
What pigmentation will be observed for the children who have Aa alleles?
_______________________________________________________
If you’re stuck on question read this
This type of combination of two different alleles is called hybrid. Often, one allele in a hybrid pair of
alleles is dominant and the other allele is recessive; this means that the dominant allele determines the
observable characteristic of the hybrid individual. Typically, the dominant allele is symbolized by a
capital letter, in this case A for the allele for pigmentation. Thus, heterozygous (Aa) individuals will have
normal pigmentation.
33
5.
What fraction of this couple's children would
you expect to have normal pigmentation? _______________
6.
What fraction of this couple's children
would you expect to have albinism? ___________________
The genotype refers to the genetic makeup of an individual. The phenotype refers to
the observable physical and physiological characteristics of an individual.
7.
Give an example of two individuals who have the same
phenotype, but different genotypes for the albinism gene. _____________
We often express the fractions of different genotypes or phenotypes as ratios.
For example, for the mating between two heterozygous parents, the genotype
fractions are ¼ AA, ½ Aa, ¼ aa, which can also be expressed as a 1:2:1 ratio.
8.
For the corresponding phenotypes, the fraction with normal pigment is
_____ and the fraction with albinism is _____, so the corresponding ratio is
____________.
Suppose a father has aa alleles and a mother has Aa alleles.
9.
Complete the Punnett Square to describe this mating and determine what
fraction of this couple's children would be expected to have albinism.
34
Stated Clearly
What is DNA and How Does it Work
http://statedclearly.com/videos/what-is-dna/
1. _____________ (or “deoxyribonucleic acid“) is a ________________. It’s a bunch of
atoms stuck together. In the case of DNA, these atoms combine to form the shape of a
__________ __________ _________________.
2. ____________ _____________ are tiny little chemicals inside our bodies that are so
important, they’re often referred to as the ___________ ______________ _____
_______________.
3. There’s about _____ different kinds of amino acids each with their own unique shape.
4. The neat thing about them, is they can be attached to each other kind of like _______
to produce an endless variety of larger particles known as _____________.
5. _________ ___________ make up proteins. _________ (along with other
chemicals) combine to make __________ _______________. Cells make up
________________. Tissues make up _____________ and organs, when they’re all put
together and functioning, form living creatures like you and me.
6. How many different kinds of proteins are found in the human body? ______________
7. DNA does a lot of interesting things. One of its main and most clearly understood
functions is to tell ___________ ____________ how to line up and form themselves into
specific ___________ shapes.
8. How many different chemicals make up the steps of the ladder in DNA? _______
9. A single DNA strand is extremely long, _____________ of letters long. For most of Its
life, it’s coiled up like a noodle and lives inside the ______________. Amino acids
however, live outside the nucleus in what’s called the ___________________.
35
10._______________ are protein building machines. They read the _________ 3 letters
at a time, suck amino acids out of their surroundings and stick them together in a chain
according to the RNA code..
11. Once a protein is built, it can then go on to do a number of different things, one of
which could be to help form a brand ___________ _______________.
12. So, to answer the original question: What is DNA? DNA is a _____________
_____________ for a living thing.
13. How does it work? ___________ creates __________, RNA creates _________,
proteins go on to form _____________.
36
Stated Clearly
What exactly is a Gene?
http://statedclearly.com/videos/what-is-a-gene/
1. Each one of our cells contains ________ strands of DNA.
2. A single strand is made of millions of particles called ______________.
3. These nucleotides come in 4 different types which scientists have labeled ______,
______, _____, and ________.
4. A ________ is a special stretch of DNA,
5. Genes make ____________.
6. Humans have roughly _____________ genes.
7. The _____________ and ____________ of a gene determine the size and shape of
the protein it builds.
8. _______________, for example, is a protein structure found in red blood cells.
9. ______________ is a digestive protein. Its unique shape allows it to break down food
inside your stomach so it can be absorbed in the body.
10. ________________ is a structural protein. Its unique shape and size allow it to link
together with other keratin proteins to form hard structures like fingernails, claws, and
beaks.
11. What are 3 “new” creatures engineers have produced by mixing and matching
genes?
37
“Bill Nye: Genes” Video Worksheet
1. Where do your genes come from?
2. What is inside every cell in your body?
3. What does DNA stand for?
4. What did Bill climb to get out of the Nye Lab?
5. How long is the DNA string model of science?
6. How many times longer is DNA than it is wide?
7. How does Bill define a Gene?
8. Why is the white blood cell dark on the computer screen?
9. What does the nucleus of the cell contain?
10. What can you do with DNA after you take it out of an organism?
a.
b.
11. What 2 organisms were combined to create the message to Bill in the petri
dish?
12. What do genes do?
13. Mom tells Richie: Genes are the set of __________________
_______________ that get passed down from _____________to child.
In the process, of course, the genetic material is ____________________
in new ways, which is why people bear resemblance to their _____________
and __________________without looking like any one relative in
particular.
14. What analogy does Bill use to describe the human set of chromosomes?
15. What is each chapter analogous to?
38
16. How many genes to humans have?
17. What do cells in the body not need to do? _________________________
18. Most species have fewer than _________chromosomes but thousands and
thousands of genes
19. Bill calls the babies “bundles of ________________________________”
20. The reproductive cell that a mother donates to her child is called the ____
21. The reproductive cell that a father donates to his child is called the ______
22. The number of cells needed to make a baby is: ______________________
23. DNA is the ___________ print for the future
24. Earlobes can be ______________or ____________________
25. A __________is a piece of the ___________ molecule
26. The four chemicals of DNA are
a.
b.
c.
d.
27. The number of chromosomes that a mule foal has is ______
28. The number of chromosomes that a horse has is ______
29. The number of chromosomes that a donkey has is ______
30. In the demonstration, the ______________ gene for rolling your tongue is
represented by the letter “R”
31. In the demonstration, the ______________ gene for rolling your tongue is
represented by the letter “r”
32. If a person has the pattern RR, then the person ________ roll their tongue
33. If a person has the pattern Rr, then the person ________ roll their tongue
34. If a person has the pattern rr, then the person ________ roll their tongue
35. What is special about the turtle in this movie?
39
40