Download 2.2 Genetics, advanced flashcards

16 Genetics
1. How many chromosomes does
human nucleus contain
2. Why does a person has a genetic
defect
3. What is Transcription?
4. What is Translation?
5. What is the end result of translation?
6. During translation, what tells the
ribosome in what order to put the
amino acids in?
7. Where in a cell does translation
occur?
8. During translation, what do the
amino acids become?
9. What is a codon?
10. Each codon codes for how many
amino acids?
11. What is a mutation?
12. Do all mutations change the
phenotype?
13. What is a silent mutation?
14. Describe the Missense mutation
15. Describe the Non-sense mutation
16. Describe the Frameshift mutation
46 chromosomes(23pairs)
Because the nucleic acids are not in the exact
right order
The process of DNA creating the mRNA strand in
the nucleus.
The process of the mRNA being read by a
ribosome in the cytoplasm
Protein synthesis
mRNA
Cytoplasm
Protein
3 nucleic acids
One
Change in the nucleotide base sequence of a
genome
NO
No change in amino acid sequence
Missense mutation eg. sickle cell
results in a codon that codes for a different amino
acid. The resulting protein may be nonfunctional
New amino acid
 ALA-PHE-LEU-TRY-STOP
 PHE-PHE-LEU-TRY-STOP
 Frameshift insertion eg. Tay-Sachs disease
Nonsense mutation eg Cystic fibrosis - a stop
codon is inserted into protein sequence
 Truncated protein
Insertion or deletion of one or more nucleic acids
If it happens at the end of a gene it may not be as
bad
17. What is Frame shift deletion CCR5?
CCR5 is our cell membrane receptor that the HIV
virus uses to attack. People with this genetic mutation
are immune to many strains of the HIV (AIDS) virus.
18. What are some causes of mutations?
Spontaneous mutations; happens during
replication
More often in prokaryotes than eukaryotes
19. Mutations occur more often in
prokaryotes or eukaryotes?
1
16 Genetics
20. Who has better repair mechanisms,
eukaryotes or prokaryotes?
21. What are 2 types of mutagens?
22. Describe radiation.
Eukaryotes
Radiation and chemical mutagens
- Ionizing radiation (x-rays) – induces breaks in
chromosomes
- Nonionizing radiation (UV light) – induces
thymine dimers
23. Describe chemical mutagens.
- Nucleotide analogs – disrupt DNA and RNA
replication and cause point mutations
- Eg. 5-bromouracil pairs with guanine
- Caffeine not a strong mutagen – but it does
effect fetal development
- Alkylating agents- used for cancer treatment
24. What is a mutant cell?
descendants of cell that did not successfully repair
a mutation
25. What are wild type mutants?
cells normally found in nature
26. What are two benefits of mutations? -Positive selection; survival of the fittest
- Negative (indirect) selection; selective removal
of rare alleles that are deleterious.
27. When does Genetic Recombination
 Recombination and transfer of genes
and Transfer happen and the types of
occurs during exchange of DNA segments
transfer?
with those of another DNA segment
 Recombinants – cells with DNA
molecules that contain new nucleotide
sequences
 Vertical gene transfer – organisms
replicate their genomes and provide copies
to descendants
 Horizontal gene transfer – donor
contributes part of genome to recipient;
three types
Transformation
Transduction
Bacterial Conjugation
28. Results of Transportation
 The transforming agent in the experiment
experiments?
was DNA; became the evidence that DNA
is genetic material
 Cells that take up DNA are competent.
29. Define Transduction
30. What is a bacteriophage?
31. How do bacteriophages replicate?

Transduction is the process by which
DNA is transferred from one bacterium to
another by a bacteriophages
Viruses that infect bacteria
They harness the replication machinery of the
host bacterial cell so the virus can reproduce
2
16 Genetics
32. What does transduction explain with
regards to antibiotic drugs?
33. What disease does transduction
experiments attempt to cure?
34. What do bacteria use in bacterial
conjugation?
35. What are the 7 major genetic
disorders?
36. What is an example of a
chromosome disorder?
37. What is another name for Down
syndrome, and why?
38. At what age does a mother increase
her chance of having a child with
Down syndrome?
39. What is the frequency of Down
syndrome?
It explains how antibiotics become ineffective due
to the transfer of resistant genes between bacteria
Muscular Dystrophy
Conjugation pilus
1. Chromosome disorders
2. Sex chromosomal disorders
3. Dominant disorders (only one dominate
allele needs to be present)
4. Homozygous recessive disorders (both
parents have rr alleles)
5. Incompletely dominant traits
6. Sex-linked traits
7. Sex-influenced traits
Down Syndrome
Down syndrome is also called trisomy 21 because
the person’s chromosome number 21 has three
chromosomes joined together instead of just two.
It starts around age 40
The frequency of Down syndrome is 1/ 800 births
for mothers under 40 years of age, but women
over 40 are 10 times more likely to have a Down
syndrome child.
40. What are the characteristics of Down Characteristics of Down syndrome include a
syndrome?
short stature; an eyelid fold; stubby fingers; a
wide gap between the first and second toes; a
large, fissured tongue; a round head; a palm
crease (the so-called simian line), and mental
retardation, which can sometimes be severe.
Their personalities are usually cheerful, goodnatured, and pleasant throughout their lives.
41. What is Amniocentesis?
Removing fluid and cells from the amniotic sac
surrounding the fetus followed by karyotyping to
detect for genetic diseases such as Down
Syndrome
42. What is caused by a missing
Cri du Chat Syndrome (cat’s cry)
segment of chromosome 5 and
presents with a moon face, small
head, a cry that sounds like a cat and
severe mental retardation?
43. What sex is XX?
Female are XX
44. What sex is XY?
Males are XY
3
16 Genetics
45. What parent determines the sex of a
newborn?
46. What is Jacob syndrome?
47. What is Klinefelter syndrome?
48. What is Triple-X Syndrome
(Turner’s syndrome)?
49. What abnormalities do females have
with Turners syndrome?
50. What happens to females with
Turner’s syndrome?
51. What is Neurofibromatosis also
known as?
52. What are the main symptoms of
neurofibromatosis?
53. What are the severe effects of
Neurofibromatosis?
The father

Jacob syndrome occurs in 1/ 1,000 births.
These XYY (an extra male chromosome)
males are usually taller than average,
suffer from persistent acne, and tend to
have speech and reading problems.
 At one time, it was suggested that these
men were likely to be criminally
aggressive, but it has since been shown
that the incidence of such behavior among
them may be no greater than among XY
males.
 Klinefelter syndrome occurs in 1/ 1,500
births. These males with XXY (an extra
female chromosome) and they are sterile.
 They are males with some female
characteristics.
 The testes are underdeveloped, they have
some breast development, and there is no
facial hair. They are usually slow to learn
but not mentally retarded.
 Triple-X syndrome occurs in 1/ 1,500
births. These are females with an extra
female chromosome: XXX. You might
think they are especially feminine, but this
is not the case. Most have no physical
abnormalities except that they may have
learning disabilities, menstrual
irregularities, including early onset of
menopause.
Have a short, have a broad chest, and webbed
neck. The ovaries and uterus are nonfunctional.
Turner females do not undergo puberty or
menstruate, and there is a lack of breast
development. They are usually of normal
intelligence and can lead fairly normal lives,
but they are infertile even if they receive
hormone supplements.
Elephant Man disease
Benign skin tumors and café au lait spots
Skeletal deformities, including a large head, are
seen, and eye and ear tumors can lead to
blindness and hearing loss.
4
16 Genetics
54. What is Huntington Disease?
55. What age group does Huntington
Disease affect?
56. How is Huntington Disease treated?
57. What is Tay-Sachs disease?
58. What demographic does Tay-Sachs
disease normally effect?
59. What are other complications of
Tay-Sachs?
60. What is Cystic Fibrosis?
61. What is the average life expectancy
for a person with CF?
62. What is Phenylketonuria (PKU)?
63. What is special about their diet?
64. When is incomplete dominance
exhibited?
65. Do carriers who have the “trait” of a
disorder have a disease?
66. What is Sickle-Cell disease?
A dominant neurological disorder that leads to
progressive degeneration of brain cells, which
causes severe muscle spasms and personality
disorders.
Most people appear normal until they are of
middle age and have already had children who
may also be stricken
No effective treatment, and death often comes ten
to fifteen years after the onset of symptoms
Homozygous recessive disorder (both parents
must have rr alleles) caused by a genetic enzyme
deficiency. Infant development begins to slow
down between 4-8 months of age. Neurological
impairment and psychomotor difficulties then
become apparent.
Jewish people
The child gradually becomes blind and helpless,
develops uncontrollable seizures and eventually
becomes paralyzed. There is no treatment or cure.
The mucus in the bronchial tubes is particularly
thick and interferes with breathing causing the
lungs to get infected frequently.
The CF gene is located on Chromosone 7
28 years old with new treatment
It is a disease that offspring of first cousins are
more likely to get. They lack an enzyme that is
needed to break down a phenylalanine (amino
acid) and this accumulates in the urine.
They have a special diet that does not contain
phenylalanine amino acid. If they get too much,
they will have neurological problems. Children
with PKU will develop mental retardation if they
don’t follow their diet.
Incomplete dominance is exhibited when there is
an intermediate phenotype.
NO…they can be carriers of a disorder without
being sick themselves but their children may have
the disorder or be carriers.
An incomplete dominant disorder
RBCs are irregular (sickle shaped)
RBCs do not carry oxygen well and get stuck in
arteries
5
16 Genetics
67. What do Sickle-Cell patients suffer
from?
68. What does it mean to have a sicklecell trait?
69. Do those infants with a sickle cell
disease or a sickle cell trait have a
better resistance to malaria than a
normal human being?
70. In malaria- infested Africa, who
survive well?
71. What is the percentage of those with
sickle cell trait to pass the sickle cell
disease to their offspring?
72. What is an allele that is only on the
X chromosome called?
73. What is an allele that is only on the
Y chromosome called?
74. Are most sex-linked alleles on the X
or the Y chromosome?
75. Are most X-linked conditions
dominant or recessive?
76. If a male has an X-linked condition
and his daughters are carriers, Will
her male children have the
condition?
77. From whom is the gene for male
pattern baldness inherited?
78. Where does your mother get the
baldness gene from?
79. Does it matter if your father or his
father was bald?
80. What three well known X-linked
recessive disorders are there?
81. On what chromosome is the gene for
the red and green cells?
82. What is muscular dystrophy
characterized by?
83. What early markers of muscular
dystrophy are seen when the child
starts to walk?
84. At what age does death usually
occur in muscular dystrophy
patients?
They suffer from poor circulation, anemia, poor
resistance to infection, internal bleeding, pain in
the abdomen and joints, and damaged to internal
organs.
The infant got a bad chromosome from only one
parent- unlike sickle-cell disease (they got a bad
chromosome from both parents.)
Sickle- cell trait; the malaria parasite normally
reproduces inside red blood cells but a red blood
cell of a sickle- cell trait infant kills the parasite.
Those with sickle cell trait; 60% of the population
there has sickle cell trait.
25%
X-linked
Y-linked
The X chromosome since it is larger.
Most known are recessive
Yes, her male children are also likely to have the
condition.
The mother
Her father
No
Color blindness, muscular dystrophy, and
hemophilia
The X chromosome
A wasting away of the muscles
Waddling gait, toe walking, frequent falls, and
difficulty rising
By age 20
6
16 Genetics
85. How does MD pass down?
86. What is a sex influenced trait?
87. What is a Genotype?
88. What is a Phenotype?
89. Genes are:
90. Alleles are:
91. What is a phenotype?
92. What is a genotype?
93. What are alleles?
94. Describe dominant and recessive
alleles.
95. What do alleles occur in?
96. Describe homozygous (pure) recessive
97. What would it mean if a person has
homozygous (pure) recessive
98. Describe homozygous (pure) dominant
99. What would it mean if a person has
homozygous (pure) dominant
100. What is the term for “pure”?
101. What is called when cream is removed
before you get it?
102. If a sperm cell donates an E and the
egg donates an e, what genotype will the
offspring have?
103. The physical appearance of a person is
called the
From carrier mother to carrier daughter
The length of the index finger is sex-influenced.
In females, an index finger longer than the fourth
finger(ring finger) is dominant. In males, an index
finger longer than the fourth finger seems to be
recessive.
Set of genes in the genome
physical features and functional traits of organism
The units of heredity that control the specific
characteristics of an individual, are arranged in a
linear fashion along the chromosomes.
a pair of genes on a pair of chromosomes that
affect the same trait. For instance, both
chromosomes have an allele for eye color, both
have an allele for skin color,etc.
what the person looks like.
the type of genes a person has, or their genetic
make-up.
Those genes that affect the same trait
A dominant allele is given a capital letter, and a
recessive allele is given the same letter in lower
case. For instance, having an earlobe that is
unattached to the face is a dominant trait, so we
can call it E. An attached earlobe would then be
called e.
Pairs.
just as one pair of each type of chromosome is
inherited from each parent, so too each pair of
alleles inherited from each parent.
If a sperm cell has e and the egg cell has e, the
offspring must have ee.
That means the person would have an attached
earlobe.
If a sperm cell has E and the egg cell has E, the
offspring must have EE.
That means the person would have an unattached
earlobe.
Homo (it refers to something being the same)
homogenized milk
Ee.
phenotype
7
16 Genetics
104. A person with Ee is called
heterozygous genotype (unattached earlobe
phenotype).
105. What earlobe alleles will a person have
who is homozygous recessive?
106. What earlobe alleles will a person
have who is homozygous dominant?
107. What earlobe alleles will a person have
who is heterozygous?
108. If one of the parents is homozygous
dominant (EE), the chances of their having
a child with unattached earlobes is
109. What if both parents are homozygous
recessive (cc)?
110. How do you calcite eye color for a child
ee
that had a father with Brown eyes (BB) and a
mother that had blue eyes (bb)?
111. What is the genotype of the offspring of a
EE
Ee
100 %, because this parent has only a dominant
allele (E) to pass on to the offspring.
there is a 100% chance that each of their children
will have attached earlobes.
Use the Punnet Square to calculate the odds of
what the child will look like. The father’s alleles
are written in the vertical column and the
mother’s on the horizontal.
100% Bb
father with brown eyes (BB) and a mother with
blue eyes (bb)?
What is the phenotype of the offspring of a
father with brown eyes (BB) and a mother
with blue eyes (bb)?
What is the genotype of the offspring of a
father with brown eyes (Bb) and a mother
with blue eyes (bb)?
What is the phenotype of the offspring of a
father with brown eyes (Bb) and a mother
with blue eyes (bb)?
What is the genotype of the offspring if both
parents were heterozygous (Bb)?
What is the phenotype of the offspring if
both parents were heterozygous (Bb)?
100% Brown
50% Bb and 50% bb
Written 1:1
50% brown eyes and 50% blue eyes
Written 1:1
One BB, two Bb, one bb
Written 1:2:1
Three with brown eyes, one with blue eyes
Written 3:1
8