Genetics Flashcards
1
Q
what is a gene
A
- a section of DNA that codes for a particular protein
- a heritable factor that controls specific characteristics
2
Q
What is an allele
A
an alternative version of the same gene
3
Q
what is a chromosome
A
wound up DNA contained in the nucleus
4
Q
what is the locus
A
the specific position of a gene on a chromosome
5
Q
what is sickle cell anemia
A
a mutation that changes the shape of you RBC to have a sickle shape
6
Q
why is sickle cell anemia a heterozygous advantage
A
- carrier’s with sickle cell anemia will be immune to malaria
7
Q
what causes SCA
A
- genetic conditions; affects minority
- homozygous recessive disease
8
Q
what type of mutation is SCA
A
a singe base substitution mutation where glutamic acid is changed for valine
GAG -> GTG
9
Q
how does SCA affect the RBC
A
- causes them to become sticky and sickle shaped (changes the shape of the hemoglobin)
- dont transport oxygen properly
10
Q
what is the genome
A
all the genetic information of your body
11
Q
what is the purpose of the human genome project
A
- to catalog the entire human genome
- to identify all the 20000-25000 genes in human DNA
12
Q
What are the uses of the HGP
A
- drug discoveries
- mutation preventions
- illuminate fundamental functions of the body
- bio tech
- risk assessment
- causes of diseases
- reduce animal testing
13
Q
Issues with the HGP
A
- privacy and fairness in use
- clinical integration in new genetic tech
- genetic research and commercialization
- education of public
14
Q
what is cystic fibrosis
A
a disease of the lungs + digestive system
15
Q
effects of cystic fibrosis
A
- very thick music is produced that blocks the airways and intestines
- patients have difficulty breathing and absorbing food
- infections can easily set in
16
Q
what causes cystic fibrosis
A
- inheritable disease
- recessive disorder
17
Q
mutation in cystic fibrosis
A
- deletion mutation
- phenylaline is deleted
- CFTR gene is affected: chanel for the movement of chloride ions in and out of cells, which maintain the balance of salt and water
18
Q
what is a mutation
A
a randome, rare change in genetic material
19
Q
can mutations be good
A
- yes, if it provides an individual/species with a better chance for survival, it is beneficial
20
Q
symptoms of sickle cell anemia
A
- fatigue
- shortness of breath
- weakness
21
Q
differences in prokaryotic and eukaryotic DNA
A
PROKARYOTIC:
- free in cytoplasm
- plasmid DNA
- no membrane
EURKARYOTIC:
- membrane-bound
- associated with histones/proteins
- in nucleus
22
Q
what is a karyogram
A
a pictorial representation of chromosomes
23
Q
how many pairs of chromosomes
A
23 pairs, 46 chromosomes in total
- one pair of sex chromosomes (determine sex. X and Y)
24
Q
what are non-sex chromosomes called
A
autosomes
25
what was the key experiment that MENDEl performed
- pea plant heredity experiment where he crossed yellow and green seeds
26
what does dominant mean
- expression of phenotype, expressed in homozygous and heterozygous form
27
what does recessive mean
- carriers of phenotype, phenotype is only expressed in homozygous form
28
what is the genotype
the combination of genes
29
what are homologous chromosomes
Homologous chromosomes are chromosomes of the same size and similar structure. In their structure homologous chromosomes have the same genes as each other in the same sequence but do not necessarily have the same allele of those genes.
30
wat is an antenatal test
- genetic test that can be performed on a fetus while it is still in the mothers uterus, to allow people to make informed decisions about their lives
- TESTS HAVE A SMALL RISK OF HARM, ESPECIALLY TOWARDS OLDER WOMEN
31
what is amniocentisis
- when amniotic fluid is taken in the second trimester
- prenatal test
- 1 in 100 result in miscarriage
32
process of amniocentisis
- 1. ultrasound
2. anaestia
3. amniocnentisis needle through abdominal wall into uterus into the amniotic sac
33
what is chorionic villus testing
- higher chance of miscarriage
| - you can do it earlier on
34
what is the genotype
symbolic representation of the pair of alleles possessed by an organism
35
phenotype
the characteristics/traits of an organism
36
domainant allele
an allele that has the same effect on the phenotype whether it is paired with the same allele or a different one. They are always expressed in the phenotype
37
ressessive allele
an allelle that has no effect on the phenotype, unless present in homozygous state
38
what are co dominant alleles
pairs of allies that both affect the phenotype when present in a heterozygote
39
what is a carrier
an individual who has a recessive allele of a gene that does not affect the phenotype
40
what are histones
- small basic proteins, with a positive charge (so they can bind to negative DNA)
- five types
41
what is a nucleosome
DNA wound around a histone, represented by 150 base pairs of DNA
42
what does a chromosome consist of
DNA wound around a histone
43
what is Caims Technique
- measures the length of DNA
- proves semi conservative replication
- levels the DNA using radioactive hydrogen isotopes which then appear on a film (Autoradiography)
44
co dominance
Co-dominant alleles
• Not all alleles are dominant or recessive;
• Some alleles are equally strong and don’t mask one another
• Co-dominant alleles both affect the phenotype when present in a heterozygote
45
example of co dominance
blood groups are an example of multiple alleles and co dominance
46
types of alleles in blood
A, B and O
47
group A and B
encode for two different enzymes that produce different surface moleucles
48
group O
is defective, does for an enzyme that isn't function/doesnt produce surface molecules
49
what are antigens
surface molecules that work with the immune system to ensure that there is no blood transfusion
50
what is glutination
when the wrong blood is given to the wrong recipients, thus causing the body to attack itself using antibodies
51
why is O- a universal donor
it does not have any antigens or rHD proteins, allowing for it to be compatible with most blood types, as the recipient antibodies won't attack it
52
why is AB a universal reciever
- because it has all the surface molecules needed
53
what is sex linkage
when a phenotype of a gene is carried by a sex chromosome
54
what is down syndrome
"Triosomy 21" is when there is a problem in MEOISIS, where the 21st chromosome has an extra chromosome
- people with down syndrome have 47 chromsomes
55
example of sex linked disease
haemophilia and color blindness
56
what is a pedigree chart
a chart of genetic history to deduce the genotypes + phenotypes of individuals
57
what is the polymerase chain reaction
-vitro method amplificiation of DNA (duplication)
58
use of PCR
- diagnose diseases
- identify bacteria and virus
- forensics and criminology
- paternity testing
59
what is a primer
a short piece of DNA made artificially
| - 2 primers are used to match the segment of desired DNA (complimentary base pairing)
60
what is DNA polymeras
a protein which copies DNA before it divides, bumps into primer and attaches nucleotides
61
what are nucleotides
the building blocks of DNA
62
Steps of PCR
Denaturation: Annealing:
Extension:
1st step: PCR
Temperature raised to separate the two DNA strands (> 900C)

Primers allowed to anneal as temperature drops (around 500C)

DNA polymerase elongates new strands of DNA (720C)
63
what is gel electrophoresis
- technique used to separate fragments of DNA by size in order to identify its origin
- enzymes chop DNA into varying fragments
- DNA fragments placed into small wells in the gel, aligned at one end
- gel is exposed to an electric current, positive at the other side so it can attract the negative DNA
- the biggest, heaviest and least charged particles to not move easily through the gel, whereas the small ones move quickly
64
what is reproductive cloning
its used to create an animal that has the same nuclear DNA as another animal
65
somatic cell nuclear transfer
- nucleus is removed from a somatic cell of the animal to be cloned
- it is placed in an enucleate egg cell
- chemical and electrical treatment stimulates the cell to undergo mitosis, and an embryo grows
- this is placed into the futures of the host animal until is its born
66
are clones always identical
no, because genes are not the only factor that affects how an organism looks
e. g. ENVIRONMENT!
- also the clones are not 100% genetically identical because the egg cell contains mitochondrial DNA from the donor
67
applications of cloning
- produce prize farm animals
- pets can be reckoned
- bring extinct animals back
68
clones in nature?
identical twins; splitting of the embryo
69
Ethical issues around cloning
- plauing god
- unatural
- religeous
70
types of cloning
- therapeutic
| - reproductive
71
aims of cloning research
- skin to repair a serious burn
- new heart muscle
- new kidney tissue
