EOC Review Packet #2
DNA Technology
1. What can DNA fingerprinting be used for? Identify crime suspects
2. Using _electrophoresis_, scientists can determine an individual’s DNA fingerprints. No two
people have the same fingerprint except for _Identical twins_.
3. 13 countries worked collectively on the _Human genone project___ project which identified all
the approximately 20,000-25,000 genes in human DNA, and determined the sequences of
the 3 billion chemical base pairs that make up human DNA.
4. This allowed scientists to find the certain DNA sequences that cause certain _diseases_.
Genetics
5. _genetics___ the study of heredity
6. ______heredity____passing of characteristics from parents to offspring
7. ____genome_______ all the genes of a particular organism
8. ____Mendel___________ is known as the father of modern genetics. He found certain modes
of inheritance by studying pea plants.
9. _Gene____ section of DNA that codes for a trait and is located on a __Chromosome___
10. __Allele____ version of a gene (ex. Tall/_short__, _Green_/yellow)
11. __Trait__ an inherited physical characteristic
12. The_Phenotype__ is the physical appearance of an organism and the _Genotype_ is the alleles
present in an organism’s genome.
13. Provide an example of a genotype for an organism that is pure-breeding for round seeds_RR_.
Pure-breeding means the organism is (Homozygous or Heterozygous) for that trait.
14. Provide an example of a genotype for an organism that is a carrier for wrinkled seeds (use the
same letters you used above)__Rr____. Being a carrier means the organism is (Homozygous or
Heterozygous) for that trait.
15. The gene for wrinkled seeds which is a recessive trait will only be expressed if the organism’s
genotype is _rr_.
16. The _DOMINANT_ form of a gene will always be expressed even if one recessive allele is present
in simple genetics (not being codominate or incomplete dominance).
17. Draw and label a diagram used to show a monohybrid cross and the probability of certain
genotypes in offspring below
18.
19.
20.
21.
The offspring of the Parental generation or P generation are referred to as the _F1_ generation.
The offspring of the answer above are the __F1__ generation.
What law states that 2 alleles for each gene separate as gamates? __LAW OF SEGREGATION__
What law states that each gene is inherited separately from other if they are on different
chromosomes? ___LAW OF INDEPENDENT ASSORTMENT__
22. Using regular dominance, show a cross between a Purebreeding cactus finch for the dominant
trait of long beak length and a Purebreeding cactus finch for the recessive trait of short beak
B
B
b
Bb
Bb
Bb
Bb
b
100 % long beak
Genotypic Ratio: 0 BB: 4 Bb: 0 bb
Phenotypic Ratio: 4 long: 0 short
23. If two of the F1 generations offspring are crossed in the punnett square you just completed?
What is the probability of the F2 generation producing a purebreeding short beaked cactus
finch? Show your cross below to prove it.
B
B
b
BB
Bb
Bb
bb
b
1 out of 4 or
25%
Genotypic Ratio: 1 BB: 2 Bb: 1 bb
Phenotypic Ratio: 3 long: 1 short
24. Another mode of inheritance is called Incomplete Dominance. This is when neither trait is
dominant to the other, and heterozygous genotypes produce a phenotype that is inbetween
both extreme variations of the trait. Show a cross below for the trait of flower color if two pink
flowers (Rr) are crossed. What is the phenotypic ratio of the offspring?
_1___ red: __2___ pink: __1___ white
R
R
r
r
RR
Rr
Rr
rr
25. Codominance is a mode of inheritance in which both gene forms or alleles are dominant. Thus,
phenotype of heterozygous organisms expressed both traits equally. Blood types (AB) and Roan
cattle are examples of this. Show a cross below of a black and white checkered chicken (BW) and
a white chicken (WW). What would the genotypic ratio be of the F1 generation?
__0____ BB: __2____BW: ___2___ WW
What percentage of their offspring would be checkered?
B
W
W
W
BW
WW
BW
WW
26. A Dihybrid cross of two heterozygotes produces offspring with a ____9:3:3:1__________
phenotype ratio.
27. Sex-Linked traits are another mode of inheritance. This means that they are controlled by genes on
___Sex____ chromosomes. Examples are __Sickle Cell Enemia__ and hemophilia
Show a cross between a father who has hemophilia and a mother who does not hemophilia.
Xh
Yh
XH
XH Xh
XH Y
H
XH Xh
XH Y
X
All of the daughters would be (homozygous or heterozygous) for hemophilia. They are all carriers.
Any of their sons would be (pure breeding for hemophilia or pure breeding for normal blood cells).
Mutations
Gene Mutations
28. Mutations are caused by __Mutagens_ like __UV_ light or chemicals. A gene mutation is a
change in _1_ or _More_ nucleotide bases of DNA.
29. A __POINT__ mutation is a type of gene mutation when only one nucleotide base is changed.
30. A __FRAMESHIFT__ mutation occurs if 1 or more nucleotide is added or deleted.
31. Read over the example on the provided, and be able to identify types of mutations and how
they will affect the amino acids. If you do not understand the examples, raise your hand and ask
for help.
Chromosomal Mutations
32. A chromosomal Mutation occurs if there is a change in the _NUMBER_ or _STRUCTURE_ of a
single chromosome or whole set of chromosomes. Below is important vocabulary for types of
Chromosomal mutations
33. ___POLYPLOIDY__ whole extra sets of chromosomes in the same cell
34. __INVERSION_ a segment of a chromosome is inserted in reverse order
35. _DUPLICATION_ a segment of a chromosome is repeated
36. _TRANSLOCATION_Chromosome pieces are moved onto another chromosome
37. __NONDISJUNCTION__ occurs when chromosomes don’t separate during meiosis
38. In plant and animal cells gametes or _SEX_ cells are _HAPLOID_ which means they have half the
number of chromosomes a somatic cell or _DIPLOID_ cell had.
39. Haploid cells are (gametic or somatic) cells with _1__ set of chromosomes from the mom OR the
dad.
40. Diploid cells are (gametic or somatic) cells with _2_ sets of chromosomes one from mom AND
one from dad.
Genetic Disorders
41. Look at the Karyotype on your review. Do you see any examples of Trisomy caused by
nondisjunction? __YES_______ If so, on what set of chromosomes? _23RD___ What disorder
does that cause? __KLEINFELTER SYNDROME__
42. Trisomy on the 21st chromosome pair causes __DOWN SYNDROME__.
43. Turner syndrome is caused by __MONOSOMY__ of the ___23RD___ pair.