UNIT 4 Chromosome Discovery and Chromosome Structure Flashcards
This “factors” carried the traits from one generation to the next.
Mendelian factors
He recognized and explored the fibrous network within the nucleus.
Walther Flemming
Walther Flemming termed chromatin as?
“Stained material”
In what phase of cell division did Walther Flemming observed cells in various stages of division and chromosomal movement?
Mitosis
He is one of the pioneers of embryology.
Theodor Boveri
Theodor Boveri provided the first evidence of ____ cell chromosomes imparted continuity between generations.
Germ cell
He confirmed and expanded upon Boveri’s observation, and described the configurations of individual chromosomes in cells at various stages of meiosis.
Walter Sutton
He experimentally demonstrated Chromosomal Theory of Inheritance using Drosophila melanogaster – pioneered “Fly Room” experiments.
Thomas Hunt Morgan (1910)
He helped establish the chromosomal basis of heredity and sex.
Calvin Bridges (1916)
Calvin Bridges showed this process using Drosophilia that caused the chromosomes to fail to separate when forming sperm and egg cells. What process is this?
Nondisjunction
This process happens during anaphase and is described to caused sperm or egg cells to contain abnormal amounts of chromosomes. In some cases, that caused the offspring produced by the sperm or eggs to display traits that they would typically not have.
Nondisjunction
Chromosome is a thread-like structure or?
Colored bodies
Chromosome is made up of what?
Protein and a single molecule of DNA
What is the function of chromosome in mitosis?
Ensure daughter cell retains its own complete genetic complement.
What is the function of chromosomes in meiosis?
- Enable each mature ovum and sperm to contain a unique single set of parental genes
- The chromosomes of a 2N (diploid) becomes haploid
This stage of cell division is most studied and is replicated condensed chromosome with chromatids.
Metaphase (chromosome)
It is a banding technique that cytogeneticists employ in order to produce a banding pattern in individual chromosome.
Giemsa banding or G-banding
Two identical strands which are the result of DNA replication and happens during the S phase of Interphase. What morphology of chromosome is this?
Chromatids
This morphology of chromosome is the central region, where the primary constriction where sister chromatids are linked.
Centromere
Centromere divides the chromosome into?
Short arm (p)
Long arm (q)
TRUE or FALSE
All chromosomes are divided particularly nicely in a p arm or q arm.
FALSE
Not all.
It is an organelle located at the centromere region that facilitates the spindle formation.
Kinetochore
It is responsible for chromosome movement at cell division.
Centromere
This occurs when a pattern of 2 or more nucleotides are repeated and the repetitions are adjacent to one another.
Tandem repeats
It is concentrated near the centromere and telomere regions of chromosomes and forms a large part of heterochromatin. It belongs to the non-coding region of genome.
Satellite DNA
Identify what type of chromosome:
- Single
- Only the normal type
- Reliably transmitted from parental to daughter cells
Monocentric
Identify what type of chromosome:
- Lacks centromere
- Genetically unstable because they cannot be maneuvered properly during cell division and are usually lost
- Cannot pass from one generation to the other
Acentric
Identify what type of chromosome:
- Two centromere
- Contributes in genetic aberration
- Not transmitted in a predictable fashion
Dicentric
Identify what type of chromosome:
- Yielding arms of roughly equal length
- Centromere is centrally located
- 5 pairs in humans
- V-shaped when separated
Metacentric
What are the numbers of metacentric chromosomes in humans?
1, 3, 16, 19, and 20
Identify what type of chromosome:
- Unequal length of chromosome arms
- q arm is longer
- 13 pairs
- J-shaped when separated
Submetacentric
What are the numbers of submetacentric chromosomes in humans?
2, 4-12, 17, 18, and X
Identify what type of chromosome:
- peak
- close to one end; yielding a small p arm
- associated with small pieces of satellite DNA that encodes rRNA
- 5 pairs
Acrocentric
What are the numbers of acrocentric chromosomes in humans?
13-15, 21, 22, and Y
Identify what type of chromosome:
- Found at the terminal end, meaning no p arm exists
- Found in plants
Telocentric
Arms length ratio of Metacentric
1.0-1.6/1.7
The 3.0 arm lengths belongs to?
Submetacentric
Arms length ratio of Subtelocentric
3.1-6.9
Arms length ratio of Acrocentric
7.0
Telomere has a tandem repeats of the hexameric sequence?
‘TTAGGG’
What are the functions of Telomere in preserving chromosome stability?
- Preventing abnormal end-to-end fusion of chromosomes
- Protecting the ends of chromosomes from degradation
- Ensuring complete DNA replication
- Having a role in chromosome pairing during meiosis
TRUE or FALSE
Individuals with longer telomeres have been reported to have a longer subsequent lifespan in some studies of vertebrate species.
TRUEEEEE
TRUE or FALSE
During early meiosis, telomeres play the distinctive function of anchoring chromosomes to the inner nuclear membrane.
TRUE
TRUE or FALSE
Telomeres cluster together into a bouquet configuration, which facilitates pairing and recombination of the heterozygous chromosomes.
FALSE
Homozygous.
This hypothesis proposes that the ends of linear DNA cannot be replicated completely during lagging strand DNA synthesis.
End of Replication Problem
This is a ribonucleoprotein enzyme that carries out the task of adding repetitive nucleotide sequences to the ends of the DNA.
Telomerase
Telomerase replenishes the telomere ____ (cap, hat) and requires no ____ (ATP, cell)
cap, ATP
TRUE or FALSE
In most multicellular eukaryotic organisms, telomerase is active only in germ cells, some types of stem cells such as embryonic stem cells, and certain white blood cells.
TRUE
TRUE or FALSE
Telomerase cannot be reactivated and telomeres reset back to an embryonic state by somatic cell nuclear transfer.
FALSE
Can be reactivated.
This model shows that telomeres accumulate damage due to oxidative stress and that oxidative stress-mediated DNA damage has a major influence on telomere shortening in vivo.
Hayflick Model
Who proposed the Hayflick Model?
Leonard Hayflick
This is used for for instance in the widely known chromosome nomenclature proposed by Levan et al. in 1964. Its values can range from 1 (if S = L) to +∞ (the limit for S = 0).
L/S or arm ratio (r)
Centromeric regions of primate chromosomes are dominated by alphoid (alpha satellite) DNA, a family of tandemly repeated nontranscribed sequences (Maio 1971).
Alphoid Chromosomes
Regions in the chromosome that stain rather lightly with G-banding tend to more be more transcriptionally active, euchromatic, and rich with?
A. guanine and cytosine
B. adenine and thymine
A
The chromosomal regions that stain darkly tend to be less transcriptionally active, heterochromatic, and rich with?
A. guanine and cytosine
B. adenine and thymine
B
Besides G-banding, what are the other types of banding?
- Reverse (R-) banding
- Constitutive heterochromatin (C-) banding
- Quinacrine (Q-) banding
- Nucleolar Organizer Region (NOR-) banding
- Telomeric R (T-) banding
RC Q NORT
G-banding is derived from the name of the stain from what compound?
Methylene blue-eosin
Methylene blue
Human chromosomes contains?
- 44 autosomes (pairs
- 2 sex chromosomes
The extra-chromosomal DNA is found in mitochrondria and what pattern of inheritance?
Matrilineal
MOTHERRRRRRRRRR
Example of Mitochondrial disease (extrachromosomal DNA)
- Mitochondrial Encephalopathy
- Lactic Acidosis
- Stroke-like episodes (MELAS)
Theodor Boveri worked on ____ embryos that provided in one of the first description of meiosis.
Ascaris
Who are the two students of Thomas Hunt Morgan?
Bridges and Sturtevant
Identify mitosis or meiosis:
It encapsulates the Law of Independent Assortment/Segregation as well as Genetic Recombination (Meiosis I [Prophase I]).
Meiosis
What are the types of Satellite DNA?
- Alpha satellite
- Beta satellite
- Microsatellite
- Minisatellite
ABBM
Example disease of Tandem repeats.
Huntington’s Disease
This type of histone serves as a linker DNA, that closes the DNA and creates a tighter structure, allowing the zigzaging pattern.
histone H1
Nucleosome “bead” consists of:
8 histone molecules + 147 nucleotide pairs of DNA
It is an anchoring proteins that forms a scaffold-base from.
Helper Proteins
TRUE or FALSE
The number of chromosome does NOT equate to the complexity of the organism. The larger the organism, the more number of chromosomes are needed.
TRUEEEEEEEEEEEEEEEEEEEEEEE
This theory explains that in Mitochondria, that 1 cell swallows another cells and happens in circular DNA.
shet nde aq sure basta
Endosymbiotic Theory
Satellite DNA is seen in?
Telomere
Acentric remains at what stage of cell division?
Metaphase
Thomas Hunt Morgan pioneered what experiment?
“Fly Room” Experiments
Thomas Hunt Morgan used this fruitfly by demonstrating the Chromosomal Theory of Inheritance.
Drosophilia melanogaster
Walter Sutton uses this type of grasshoper to describe the configurations of individual chromosomes in cells at various stages of meiosis?
testes of Brachystola magna
What is the sub band for dup 17p11.2 or the Potocki-Lupski?
1
What is the sub band band for dup 17p11.2 or the Potocki-Lupski?
2
Which one is not part of the group in terms of biochemistry?
a. DNA
b. Scaffold
c. Histone
d. CSPs
a. DNA
DNA is a nucleid acid, all of choices are proteins.
The chromosome structure consists of:
a. DNA
b. RNA
c. Protein
d. All of the above
d. All of the above
Which of the following is NOT TRUE regarding the region of the centromere?
a. Primary constriction where sister chromatids are linked
b. Consists of several hundred kilobases of repetitive DNA
c. Prevents abnormal end-to-end fusion of chromosome
d. Responsible for chromosome movement at cell division
c. Prevents abnormal end-to-end fusion of chromosome
This is telomere.
Chromosomes can be classified based on:
a. number
b. position
c. based on arm ratio
d. all of the choices
d. all of the choices
Which of the following is a correct classification of chromosomes based on the number of centromeres?
I. Monocentric
II. Metecentric
III. Submetacentric
a. I only
b. I, II
c. I, II, III
a. I only (Monocentric)
II and III are L/S ratio
Morphologically, the following chromosome is: Y
a. Metacentric
b. Submetacentric
c. Acrocentric
d. Subtelomeric
c. Acrocentric
Modified True or False:
In telocentric, the centromere is located very close to the end of the chromosome that the p arms would not, or barely, be visible. This chromosomes are not present in healthy humans.
Both statements are correct.
Which among these statements of dicentric chromosome are true?
a. Reliably passed from parental to daughter cells
b. Is left at the metaphase plate at anaphase because they lack kinetochore
c. The broken fragment left after breaking off from a chromosomal fragile site
d. Fused chromosome in cases precipitated by conditions like Robertsonian Translocation
d. Fused chromosome in cases precipitated by conditions like Robertsonian Translocation
A - cannot passed bc of centromeric regions
B - cannot leave
C - acentric
Which of these following statements of telomere are correct? Select all that apply.
a. Present only in nonlinear DNAs of eukaryotes
b. Passed through the metrilineal line
c. Anchors chromosomes to nuclear walls in meiosis
d. Shortens over time with age
c. Anchors chromosomes to nuclear walls in meiosis
d. Shortens over time with age
A - linear DNAs
B - passed through the mitochrondrial line
____ is a structure that occurs when a chromosome breaks in two places and its broken ends fuse together.
Ring
Use Levan’s L/S ratio:
P arm length is 1; Q arm length is 1
L/S ratio 1 = metacentric
A. biggest chromosome in karyotype
B. last and penultimate autosomes, and male determining chromosome
C. some chromosome of the Shamrock species of plants
D. female sex chromosome (2 of them)
A. biggest chromosome in karyotype
Use Levan’s L/S ratio:
P arm length is 0.5, Q arm length is 1.5
L/S ratio 3 = submetacentric
A. biggest chromosome in karyotype
B. last and penultimate autosomes, and male determining chromosome
C. some chromosome of the Shamrock species of plants
D. female sex chromosome (2 of them)
D. female sex chromosome (2 of them)
Use Levan’s L/S ratio:
P arm length is 0.2, Q arm length is 1.2
L/S ratio >7 = Subtelocentric
A. biggest chromosome in karyotype
B. last and penultimate autosomes, and male determining chromosome
C. some chromosome of the Shamrock species of plants
D. female sex chromosome (2 of them)
B. last and penultimate autosomes, and male determining chromosome
The _____ structure of chromatin is a model for the structure of 30 nm fibre. It is secondary chromatin structure which helps to package DNA into the nucleus.
Solenoid
Identify this chromosomal alteration:
i(X)(q10)
Isochromosome
In cytogenetics, the naming of chromosomal aberrations such follows notations like the 22q11.2 which represents the disease DiGeorge. The one one point two notation part is made possibly by ____ of the transcriptionally active regions of the chromosome known as bands, sub bands or sub sub bands.
Staining
