Genetics final test Flashcards
1
Q
Robert Hooke observed the cells for the first time in…
A
1665
2
Q
Anton van Leeuwenhoek discovered living organisms in water in…
A
1683
3
Q
Brown discovered the nucleus in the cell in…
A
1833
4
Q
Rudolf Virchow summarized the state of the current knowledge in latin in…
A
1858
5
Q
Charles Darwin published his work on evolution and natural selection in…
A
1859
6
Q
Mendel published his “Versuche uber Pflazen-hybriden” in…
A
1865
7
Q
How were mendel’s laws of heredity divided?
A
- The law of segregation - Alleles segregate randomly into gametes
- The law of independent assortment - genes do not influence each other with regard to the sorting of alleles into gametes
- The law of dominance - If you breed two individuals with different traits the next generation will have one of each. The trait that is visible is the dominant one.
8
Q
Fredrich Meiser isolated the nuclei in…
A
1869
9
Q
Thomas Hunt Morgan used Drosophila Melanogaster (fruit fly) to prove that hereditary traits are carried by chromosomes in…
A
1910
10
Q
Oswald Avery, Colin MacLeod and Macyl McCarty solved the mystery of transforming principle using a process of elimination in…
A
1944
11
Q
Transposons - jumping genetic elements was found by Barbara McClintock in…
A
1948
12
Q
The DNA structure was found by F. Crick, J. Watson, R. Franklin & M. Wilkins in…
A
1953
13
Q
The genetic code was found by Khorana, Nirenberg & Ochoa in..
A
1966
14
Q
Reverse transcriptase was found by Baltimore, Temin & Mizutani in…
A
1970
15
Q
Fredric Sanger invented a new method to reveal DNA sequence in..
And received the noble prize in..
A
1977
Nobel prize: 1980
16
Q
PCR (Polymerase Chain Reaction) was invented by Kary Mullis in…
A
1987
17
Q
When were the different genomes found?
A
2000 - fruit fly
2001 - human
2002 - mouse
2004 - chimpanzee, dog, chicken, bee, rat
2007 - cat
2009 - pig
18
Q
All animals are diploid (true/false)
A
True
19
Q
Diploid means..
A
In each cell there are 2 copies of the same gene (one from each parent) (46 chromosomes)
20
Q
Haploid means..
A
In each cell there is 1 copy of a gene. (23 chromosomes)
21
Q
What -ploid are plants? Haploid or diploid?
A
Plants can be triploid, tetraploid and so on..
22
Q
Allele means…
A
Gene variants, two or more variants of the same gene with a specific place (locus) in the chromosome
or
The different forms of a segment of DNA that can exist at a particular site in a chromosome
23
Q
Cell cycle and what phases it consists of..
A
The cell cycle is divided into I for Interphase and M for mitosis/meiosis
Interphase consists of:
- G1 - the gap 1 phase
- S - the synthesis phase
- G2 - the gap 2 phase
- G0 - the resting phase
24
Q
Mitosis is a mechanism that results in..
A
- 2 daughter cells
- Chromosome number and genetic information are conserved
25
What are the different phases of Mitosis and Meiosis?
Mitosis:
- Prophase - membrane disappears
- Metaphase - the spindle develops and the chromosomes line up
- Anaphase - Cromosomes get pulled apart
- Telophase - two cells are formed with the chromosomes and nuclei get developed
- Cytokinesis - The two cells separate
Meiosis:
- Prophase I - membrane disappears and sometimes crossing over can occur between the chromosomes
- Metaphase I - spindle is formed and chromosomes line up
- Anaphase I - the chromosomes get pulled apart
- Telophase I - cells start to form and nuclei get developed
Cytokinesis - the cells get separated
- Prophase II
- Metaphase II
- Anaphase II
- Telophase II
- Cytokinesis
--- Repetition of the first steps
26
What is gametogenesis?
Cell division and differentiation leading to the formation of haploid gametes with recombined chromosomes
27
Differences in female gametogenesis in different species
- Dogs and rodents : can primarily find oocytes even in sexually mature females
- Rabbit - the ovulation is induced by insemination, not by periodic hormonal level changes
28
Male vs female gametogenesis
29
Which process induces the zygote pronuclei fusion?
Mitosis
30
Consider no mutations at all. What is the significance of crossing over?
Linking the chromosome in bivalents (not increasing diversity)
31
Spermatocytes are linked by cytoplasmic bridges in order to:
Synchronize their divisions
32
Eucaryotic vs procaryotic chromosome
Eucaryotic - composed of one or two linear double helix DNA molecules. Has many replication initiation sites.
Procaryotic - composed of one circular double helix DNA molecule. Has only one replication initiation site.
33
Number of cells in our body. Lenght of each cell's DNA. Total length of human's body DNA.
37,2 Trillion cells
2 meters of DNA length per cell
74,4 billion km of length, or 250 trips to the sun and back
34
Condensed chromosome structure and how it gets there
35
Chromosome structure (names of the different parts)
36
Centromere location, names
37
Chromosome staining produces a banding pattern dependent on...
- How tightly chromatin is condensed
- What is the ratio of G-C and A-T in DNA sequence
38
What does chromosome staining allow us to identify?
It allows us to identify homologous chromosomes and changes in karyotypes such as chromosomal abnormalities.
in short:
- Homologous chromosomes
- Changes in karyotypes
---> Abnormalities
39
G-banding, what stain and what does it show?
Giemsa stain
- It shows darker colors in regions with high A-T content
- Light color in active regions
40
Q-banding, what stain and what does it show?
Quinacrine stain
- It shows fluorescent bands in regions with high A-T content
41
R-banding, what stain and what does it show?
Reverse Giemsa stain
- It shows dark bands in places with high G-C content
(Inverted G-banding)
42
C-banding, what stain and what does it show?
Constitutive heterochromatin stain
- Dark bands in densely packed heterochromatic regions
43
Ag-NOR banding, what does it show?
It shows dark bands in nucleoar organising regions
44
What is a idiogram?
A schematic depiction of the karyogram
- shows typical banding pattern
45
What is aneuploidy? How many infants are born with it? How many miscarriages are aneuploid?
- Aneuploidy is the most commonly identified chromosome abnormality in humans. Cell division abnormalities.
- About 1 in 300 infants are born with it
About 1 in 3 miscarriages are aneuploid
46
Examples of aneuploidy
- Down syndrome - trisomy 21
- Klinefelter syndrome
- Edwards syndrome - trisomy 18
- Patau syndrome - trisomy 13
47
Chromosomal theory of inheritance
1. Genes have their loci on chromosomes
2. Genes are located linear along the chromosomes
3. Genes on the same chromosome create a linkage group
4. Homologous chromosomes can interchange their fragments via crossing-over
5. The frequency of interchange between two loci is dependents on the distance between them
48
Class 1 and 2 markers
Class 1 - proteins
- One quality trait determined by one allele pair which is useful for genetic analysis
Class 2 - DNA
- Polymorphic non-coding DNA sequences
49
Genetic markers significance
- Pedigree research
- QTL - Quantitative Trait Loci
- MAS - Marker Assisted Selection
- GWAS - Genome-wide Association Study
50
Linked traits
- Mammals have 20 000 genes on 23 chromosomes
- Genes located on one chromosome are more frequently inherited together than genes on different chromosomes
51
First genetic map, sturtevart was made in... by...
it was made in 1913 by T.H. Morgan student
52
Lethal alleles..
- Decrease fitness
- Usually cause premature death in recessive homozygotes
53
Non-allelic genes interaction
- Involves the interaction between two or more genes
54
Supplementary genes
- Two non allelic dominant genes that interact and result in a new phenotype
55
What is epistasis?
When one gene masks the effect of the other gene
56
Epistatic gene vs Hipostatic gene
Epistatic - The gene that masks another gene
Hipostatic - gene that's masked by another gene
57
Complementary genes
- Two independent pairs of genes which interact to produce a trait together but each dominant gene alone does not show its effect
58
Modifier genes
- They change the phenotypic expression of another gene
59
What is the latin name of the fruitfly from the experiments?
D. melanogaster
60
Why do we use them for breeding experiments?
- Short life cycle - 10-15 days
- High fertility - 500 eggs in lifespan
- Easy to culture
- Many genes are similar to human
61
How to determine the sex of a fruit fly?
Based on their abdomen, females have large striped abdomens and males have smaller abdomens with a big black stripe on the bottom.
Males also have sex combs on their first pair of legs
62
What do fruit flies in the lab eat and what do we use for anesthesia?
They eat corn meal food with yeast, propionic acid and paraben (anti-mold)
For anesthesia we use chloroform or chilling
63
Where is the polytene chromosome in flies?
In the salivary glands and other secretory glands
64
What are the four DNA and RNA bases?
DNA:
- Adenine
- Cytosine
- Guanine
- Thymine
RNA:
- Adenine
- Cytosine
- Guanine
- Uracil
65
Types of cells:
Stem cells ->
- Muscle cells
- Blood cells
- Nerve cells
- Cardiac cells
- Liver cells
- Intestinal cells
66
Transcription factors
- Proteins binding to the regulatory DNA regions, facilitating or inhibiting transcription
67
Homeotic genes
- Genes which regulate the development of anatomical structures in various organisms
68
Epigenetic regulation
- Gene expression regulative mechanism, which are hereditary, but do not include changes in the DNA sequence
69
DNA methylation
- Addition of methyl group to cytosine
- Decrease in transcription factor affinity
70
Histones modification
- Chromatin remodeling
- Histone tail modification changes histone affinity to DNA
71
X-chromosome inactivation
- Only one X chromosome is active
- It is a kind of imprinting
- THe process is random and takes place during morula --> blastocyst transition
72
What does PCR stand for?
Polymerase Chain Reaction
73
What process is important in PCR?
DNA replication
74
What is ivermectin?
- Anti-parasitic drug, macrocyclic lactone form avermectn family,
- Used for animals and humans,
- Kills wide variety of parasites including worms and mites
- Does not penetrate blood-brain barrier.
75
Symptoms of Ivermectin hypersensitivity in dogs
Neurological symptoms
- apathetic,
- lack of coordination,
- convulsion,
- coma,
76
What is the cause of Ivermectin hypersensitivity in dogs?
Deletion of 4 nucleotides in MDR1 gene coding ABCB1 transporter.
77
What is PCR?
It's DNA replication on repeat
78
What steps occur in PCR and at what temperatures?
Denaturation - 94-96*C
Annealing - 68*C
Elongation - ca. 72*C
79
What are mutations?
What is the cause of mutations?
Are they all heritable?
What are mutations?:
- Uncorrected mistakes during replication or cell division.
- Permanent alterations of the nucleotide sequence
What is the cause of mutations?:
- Errors during DNA replication or other damage to DNA
- Errors during DNA repair
- Insertion or deletion of segments of DNA
Are they all heritable?:
- no
--> Mutation causing death or infertility before reproduction
--> somatic mutations (do not give rise to sex cells)
- yes
--> germ-line mutation (in reproductive cells)
80
Chromosome aberrations (mutations of part of one or two chromosomes) balanced vs unbalanced
Balanced
- translocation
- fusion
- centric fusion
- inversion
-- Decreases fertility
Unbalanced
- deletion
- duplication
- isochromosomes
-- Mostly lethal
81
What is a population?
A group of organisms of the same species that are found in the same area and can interbreed
