4.4 Genetic Engineering and Biotechnology

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12 Δεκ 2012 (πριν από 4 χρόνια και 6 μήνες)

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Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


4.1
Chromosomes, Genes, Alleles and Mutations

1.

How many chromosomes are present in a diploid human cell?


2.

Distinguish between
haploid

and
diploid
.



3.

Distinguish between
chromosomes

and
chromatids
.


4.

Define
gene
.



5.

Define
gen
ome
.



6.

What is a
gene locus
?



7.

Define
allele
.



8.

Give two examples of genes and some of their possible alleles.




9.

Define
mutation
.



10.

What factors can increase the chance of a genetic mutation?


11.

Define
evolution
.




12.

How can mutations lead to
evolution by natural selection
?



Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


13.

What level of protein structure is affected by a change in amino acid sequence of a polypeptide?
Why?


14.

Compare the following types of
base
-
substitution mutation
.


Silent mutation

Mis
-
sense mutation

Nonsense mutation

Number of bases
substituted

1



Effect on polypeptide



Stop codon produced
early


polyp数瑩ee
獨潲s敮敤

䕸慭pl攠楬汮敳e


卩捫汥cc敬氠摩獥慳e



ㄵ1

Describe the effects of sickle cell disease on sufferers

in terms of:

a.

Hemoglobin production


b.

Symptoms and mortality



16.

In which parts of the world could a
single
sickle cell (Hb
s
) allele

be beneficial? Why?





17.

How is the spread of the sickle cell gene an example of natural selection in action?




18.

How could

this be an example of a
correlation

which has a strong element of
causality
?


Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


19.

Using the NCBI gene database at
http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene

, find the
gene locus of the H
BB (hemoglobin) gene.



20.

Human Nutrition and Health link:

Using the same database, look for the gene related to the illness PKU (phenylketonuria)

a.

What is the gene name?


b.

What is the gene locus of this gene?


c.

Which enzyme is encoded by this gene?


d.

What is the consequence of a base
-
substitution (mis
-
sense) mutation of this gene?





e.

How is PKU diagnosed and why must it be diagnosed as early as possible?



21.

Stem cells link:

Read this article:
http://notexactlyrocketscience.wordpress.com/2007/12/08/sickle
-
cell
-
mice
-
cured
-
by
-
stem
-
cells
-
reprogrammed
-
from
-
their
-
own
-
tails/


a.

What is an IPS stem cell?


b.

Outline the
use of this technology in treating the mice with sickle cell disease.






Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


22.

Define
homologous chromosomes
.



23.

What is meant by the term
reduction division
?




24.

What is the function of meiosis?



25.

Add chromosomes and annotate the diagram below summarizing the steps in meiosis.

Where does
crossing
-
over

occur?




26.

Compare mitosis and meiosis:


Mitosis

Meiosis

Number of divisions



Number of daughter cells



Chromosome number in
daughter cells



Functions:





Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


27.

Outline the major events and movements of chromosomes occurring at these stages of meiosis:


Meiosis I


Meiosis II

Prophase I



Prophase II


Metaphase I



Metaphase II


Anaphase I



Anaphase II


Telophase I



Telophase II


Cytokinesis



Cytokinesis


Interphase







28.

a. A cell with a diploid number of 12 chromosomes meiosis. How many daughter cells will be
produced and with how many chromosomes in each?



b. A gamete contains 18 chromosomes. How many chromosomes in the somatic cell?



c. A diploid cell with 16 chromosomes undergoes meiosis. How many chromatids are present in
metaphase I?




Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


29.

Describe what you can see in this image.



30.

Distinguish between
chromosomes,

sister chromatids

and bivalents
.



31.

During which stage of meiosis is the image in Q8 most likely to be seen?




32.

How does
random orientation

in metaphase I lead to further genetic variation? How many
possible orientations are there in human ce
lls?






33.

How does sexual reproduction lead to even further genetic variation within a species?




Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com



34.

Annotate the diagram below to show what happens in
non
-
disjunction

in meiosis II.




















35.

How does
non
-
disjunction

lead to
trisomy
?




36.

Distinguish between non
-
disjunction and trisomy.



37.

Compare the outcomes of non
-
disjunction in anaphase I with anaphase II:


Non
-
disjunction in…

Anaphase I

Anaphase II

Number of normal cells



Cells with extra chromosome (n+1)



Cells with chromosome

missing (n
-
1)




Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


38.

Using information in the graph, outline the effect of maternal age on likelihood of Down
Syndrome:


















39.

What are some of the effects of Down syndrome?



40.

A
karyotype

can be used to test for non
-
disjunction disorders. Fetal cells are taken and the
number of chromosomes counted. Outline how these cells are retrieved:

Chorionic Villus Sampling (CVS):



Amniocentesis:



41.

How can performing a nuchal translucency (NT) sca
n reduce the number of healthy fetuses
terminated as a result of amniocentesis?
http://www.guardian.co.uk/society/2009/may/16/health
-
nhs


Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com



42.

Which three visual aspects of homologous ch
romosomes can be used to
identify them for the purpose of a karyotype?


a.

Banding patterns


b.




c.







43.

Analyse this karyotype.









Remember: Meiosis is the key to success in Biology.

If we understand how meiosis works and
gives rise to genetic variation, we can understand how life has evolved and adapted. Make sure
you can explain all of the ways in which meiosis leads to variation amongst a population.


Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com



44.

Assign the keywords to the c
orrect definitions:

Genotype

Phenotype

Dominant allele

Recessive allele
Codominant alleles

Homozygous

Heterozygous

Carrier

Gene locus



45.

Summarise the rules for writing genotypes in these crosses

Dominant/recessive

alleles



Codominant alleles


Sex
-
linked traits







Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


46.

Define these keywords:


Monohybrid cross


Punnet grid


Mixed phenotype


Phenotype ratio


Test cross



47.

Complete the punnet grid below to show the outcome of the monohybrid cross that results in
peas of different colours.


Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


48.

Complete the punnet grid below to show the possible outcomes of a cross between
two
members of the F1 generation
.

49.

In the examples above, identify individuals which are:


a.

Homozygous dominant



b.

Heterozygous


c.

Homozygous recessive



50.

The allele for red flower colour (R) is dominant over white (r).

A student suspects that a red flower is heterozygous. Explain how she coul
d use a
test cross

to
verify this.










Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


51.

Some genes have
multiple alleles
. What does this mean?




52.

Complete the table below to show how blood types are inherited.

53.

Which blood type is an example of
codominance
?



54.

Complete this pedigree chart to show the inheritance of blood types in this family.


Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


55.

Sickle cell is another example of
codominance
.


56.

Predict the phenotype ratios of offspring in the following crosses. Show all your working, and set
it out as expected.
Take care with notation.




Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


b.

Carrier mother crosses with carrier father.










c. Heterozygous father with sufferer mother.








57.

Explain the prevalence of sickle cell in Africa, in terms of natural selection.





58.

Phenotype ratios predict the number of offspring of a certain phenotype. Which statistical test
can be used to compare this expected number with the observed outcome of an investigation?


Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


59.

Distinguish between
autosomes

and
sex chromosomes
.




60.

Distinguish
between the female (X) and male (Y) chromosomes in humans, in terms of size,
homologous regions and number of genes.





61.

Complete a punnet grid to show how gender is determined in humans.










62.

What is the role of the
sry gene

in gender determination?




63.

How might meiosis lead to problems with gender determination?





Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


64.

a. Define
sex
-
linkage
.


b.

State two examples of sex
-
linked genetic disorders.


b. Explain why sex
-
linked disorders are more common in males than females.




65.

T
he allele for colour blindness (n) is recessive to the allele for normal vision (N). This gene is
carried on the X chromosome. Complete the table below to show the genotypes and
phenotypes of individuals with regard to colour blindness.


Female

Male

Normal

X
N

X
N


Affected



Carrier


Not possible! Why?


66.

In the space below, complete a punnet grid to show a cross between a normal male and a
carrier female. What is the expected ratio of phenotypes?









Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


67.

Hemophilia is a blood
-
clotting disorder that is also sex
-
linked.

a.

Outline the effects of hemophilia.



b.

Use the pedigree chart to answer these questions.

What is the genotype of Leopold? Why?



What is the genotype of Helen? Why?




Which two females’ symbols need to be
amended? Why?


What are the possible genotypes of Bob?


c.

Outline one form of genetic engineering used to help patients with hemophilia.




68.

What effect might you expect to see of successful treatment of sex
-
linked dis
orders on the
frequency of faulty alleles in the population? Explain why.





Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


69.

Use the pedigree chart of the mystery trait below to answer these questions.

Create your own key
: symbols are standard.



Key:




a.

Is this trait dominant or recessive? How do you know?


b.

Is this trait autosomal or sex
-
linked? How do you know?



c.

How could you determine whether an affected female was homozygous or heterozygous for
the mystery trait?






Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


4.4
Genetic Engineering and Bi
otechnology


Top resources to use for this section:


Learn.Genetics @ Utah

(great simulations and animations):
http://learn.genetics.utah.edu/



Human Genome Project:

http://www.genome.gov/10001772

and
http://www.ornl.gov/sci/techresources/Human_Genome/home.shtml



BioEthics Education Project
:
http://www.beep.ac.uk/content/index.php




70.

The
polymerase chain reaction

(PCR)

is used where DNA samples are too small to be useful.


a.

What is the purpose of PCR in labs and investigations?



b.

Which cellular process does it mimic?



c.

What is the role of high temperatures in PCR?



d.

What is the role of complementary base pairing in PCR?



e.

Why is it called a
chain reaction
?





71.

What are two main uses of DNA profiling by electrophoresis?





72.

What are some other names for DNA profiling?




73.

What are the roles of the following components of gel electrophoresis?


a.

Restriction enzymes


b.

Gel


c.

Electric current


d.

Fluorescent DNA markers


Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


74.

Annotate the image below to outline briefly how gel electrophores
is works.



















75.

Use the gel electrophoresis results below to answer these questions.

In this case, a DNA sample was taken from a cigarette found at a crime scene.




a.

Which criminal, Rob McCarr or Nick Allott, left their dribbly cigarette
-
end at the crime scene?

How do you know?




b.

Colour in bands to show where the
standard

fragments would be observed. What is the
standard used for?


c.

What evidence is there to suggest

that Nick and Rob are related?




Further research:


What are the ethical issues associated with a criminal suspect DNA database?

How might a DNA sample database impact the rights of the innocent? Is this a fair price to pay for
potentially more rapid resolution of criminal cases such as rape?


Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com



76.

This father thinks that the second child is not his


he looks too different from him!

He has seen the mother and the mailman chatting and is suspicious. He stole some hair from all
family members and swabbed a cup the mailman used and ran a gel electrophoresis to confirm
his suspicions.



77.

.



















Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com



78.

Case Study: The Story of Baby 81.
http://www.beep.ac.uk/content/186.0.html


How was DNA profiling used to resolve the case of this baby found in the aftermath of the 2004
tsunami?







79.

What is the
Human Genome Project
?



80.

What were the goals of the HGP (
http://www.beep.ac.uk/content/187.0.html

)?





81.

Look at some of the HGP resources at
http://www
.genome.gov/25019885



a.

What was the role of
E
. coli

in the HGP?



b.

How were differently
-
coloured nucleotides used in sequencing the genes?





c.

Why was the information collected stored in public databases?







82.

How did the HGP develop knowledge in the following fields?


Evolutionary research



Medicine



Bioinformatics



Ethical, Legal and Social Issues (ELSI)?


Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


83.

What is
gene transfer
?




84.

How is the
universality of the genetic code

central to gene transfer applications?





85.

What is a
transgenic organism
?




86.

What is the role of the following in gene transfer:

Restriction enzymes


E. coli plasmids


Ligase


Vector



87.

Annotate the diagram below to outline the process of gene transfer:




88.

How can the Human Genome Project allow gene transfer technology to develop more rapidly?

Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


89.

How is gene transfer used in
industrial production of insulin
?







90.

Outline the use of gene
transfer in gene therapy to treat SCID.


a.

SCID is…



b.

Gene therapy can treat SCID by…





91.

Further research: find out about one more successful use of gene therapy in human medicine.







92.

Give three examples of genetically modified plant crops and the effects of their new genes.


New properties

Advantages

‘Golden Rice’










93.

Outline how genetically modified sheep can help hemophiliacs.





94.

Discuss the benefits and potential dangers

of one type of genetic modification used in
agriculture. Why are some groups protesting GM (genetically modified) foods or crops?





Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


95.

Define
clone
.



96.

Give three examples of naturally occurring clones.




97.

Dolly the Sheep was produced by cloning using a differentiated nucleus.


a.

What is a
differentiated nucleus
?




b.

Why was the differentiated nucleus taken from an udder cell?



c.

Suggest one reason why Dolly died younger than normal, but of age
-
related illnesses.





98.

Outline the method used to clone Dolly the Sheep.



























Essential Biology 4
: Genetics (SL)



Stephen Taylor

Bandung International School

http://sciencevideos.wordpress.com


99.

Distinguish between
reproductive cloning

and
therapeutic cloning
.









100.

What are some of the medical applications and benefits of therapeutic cloning?








101.

Discuss the ethical considerations of therapeutic cloning in humans.








102.

How might stem
-
cell reprogramming (IPS cells) mitigate the negative opinions of human
therap
eutic cloning?