QUIZLET Chromosome Discovery and Chromosome Structure Flashcards
Carried traits from one generation to the next
Mendellian Factors
Who is the father of Genetics?
Gregor Mendel
What did Gregor Mendel use to study the laws of heredity?
Pea Plants
Gregor Mendel tried to isolate something that was being transferred from one generation to another that shows up as the ________________________ that he has calculated the math for
different phenotypes
Mendel’s law is true throughout the different discoveries of how genes and traits are passed because he had a ____________________ proof.
mathematical
True or False: The discovery of the chromosome occurred before Mendel’s discovery about heredity.
False
(chromosome discovery - almost two (2) decades after Mendel’s work)
Who is the individual that helped elucidate the factors that are being explained by the Mendelian laws?
Walther Flemming
What was the term Mendel used to describe the thing being carried out from one generation to another?
Factors
True or False: The majority of the scientists are looking at the center of the eukaryotic cell called the nucleus as the part of the cell where the genetic material is being carried out from one generation to the next.
True
Recognized and explored the fibrous network within the nucleus
Walther Flemming
What is the fibrous network within the nucleus called?
Chromatin
True or False: The chromatin was explored by Flemming in the idea that these are the ones that carries out the Mendelian laws.
True
Chromatin is also known as…
“stainable material”
He observed cells in various stages of division and recognized that chromosomal movement during mitosis offered a mechanism for the precise distribution of nuclear material during cell division.
Walther Flemming
He is one of the pioneers of embryology.
Theodor Boveri
True or False: In the different phases of mitosis, we look at the doubling of the chromosome to become trivalent before they separate again during metaphase as the trivalent goes back to being bivalent and is pulled to different poles after they have been aligned in the equator.
False
(Not trivalent, it’s tetravalent)
He did not simply look at the nuclei, unlike Walther Flemming and his contemporaries who focused on that.
Theodor Boveri
Provided the first evidence that germ cell chromosomes imparted continuity between generations
Theodor Boveri
Theodor Boveri looked for _________________ changes to form the new offspring from the union of gametes.
cytoplasmic changes
His work on Ascaris embryos provided one of the first descriptions of meiosis
Theodor Boveri
Did not only focus on the mitosis and nuclei but also in the cytoplasmic aspect of meiotic divisions
Theodor Boveri
Theodor Boveri’s work on _____________ embryo provided one of the first descriptions of meiosis
Ascaris
He is a parasitologist who looks into the embryo of Ascaris spp.
Theodor Boveri
Division on meiosis can be described in what levels?
- Nuclear Level
- Chromosomal Level
How many products does meiosis have in women?
4 (1 mature egg and 3 polar bodies)
Among the four products of meiosis in females, one of them becomes a ____________________, while the other three becomes ______________________.
mature egg; polar bodies
Confirmed and expanded upon Boveri’s observations
Walter Sutton
Described the configurations of individual chromosomes in cells at various stages of meiosis (testes of Brachystola magna)
Walter Sutton
What did Walter Sutton use in describing the configurations of individual chromosomes in cells at various stages of meiosis?
Brachystola magna
What is Brachystola magna?
Grasshopper
Who was the scientist focusing on mitosis?
Walther Flemming
What is the cornerstone of mitotic and meiotic analysis, as well as the building up of modern genetics and cytogenetics?
Model Animals
Who were the scientists focusing on meiosis?
Walter Sutton and Theodore Boveri
The experiments of Flemming, Sutton, and Boveri provided the physical basis of the Mendelian Law of Heredity, which eventually led to the development of what theory?
“Chromosomal Theory of Inheritance”
An extension of the dominance principle in heredity is seen in…
Sex Cells
Autosomes are involved in what cell process?
Mitosis
Where you would see dominant and recessive patterns
Sex-linked Traits
This theory states that genes do not affect each other, others chance of being inherited is seen as we divide the chromosome into gametes in meiosis.
Independent Assortment and Segregation
Sex chromosomes are involved in what cell process?
Meiosis
Experimentally demonstrated Chromosomal Theory of Inheritance using Drosophila melanogaster - pioneered “Fly Room” experiments
Thomas Hunt Morgan
What did Thomas Hunt Morgan use in demonstrating the Chromosomal Theory of Inheritance? (Scientific name)
Drosophila melanogaster (fruitfly)
He bred thousands of flies to prove mathematically what sex-linked inheritance is like.
Thomas Hunt Morgan
He had combination of traits including eye color, eye shape, wings, wing shape, and etc. using flies (fruit flies), which are easy to breed (they create generations and generations of flies.
Thomas Hunt Morgan
He is an American scientist who is also the founding father of modern cytogenetics or genetics in general.
Thomas Hunt Morgan
PhD holder working in his own lab at Colombia, USA and had several students who also contributed to the field of Cytogenetics that became noble owners, such as Calvin Bridges and Alfred Sturtevant
Thomas Hunt Morgan
Who were the students of Thomas Hunt Morgan? (2)
Calvin Bridges
Alfred Sturtevant
She is a professor at FOP that owns a Gestational Diabetes Laboratory and some co-faculties work under her and have completed their PhD during the process.
Dr. Ruth Pineda-Cortel
Helped establish the chromosomal basis of heredity and sex
Calvin Bridges
His important contribution in the field of Cytogenetics is the study of Nondisjunction of chromosomes during meiosis that contributed to the analysis of traits whether they are affected by the number of chromosomes, or known as Haploidy
Calvin Bridges
This has a very important role in the aberrations seen in phenotypes that they expressed which are now considered as rare diseases, such as Down Syndrome.
Nondisjunction
An abnormal number of a chromosome set, such as the 21st set having three chromosomes caused by non-separation or nondisjunction of chromosomal elements during meiosis.
Aneuploidy
One of the lifetime results of aberrations in chromosomal inheritance patterns
Nondisjunction (including Aneuploidies)
These are threadlike structures or “colored bodies.”
Chromosomes
Soma means…
Body
Chroma means…
Color
Means they are carried in the 44 pairs of bodily chromosomes, in which the last pair is the gametes
Autosomes
Chromosomes are made of… (2)
Protein
DNA (a single molecule)
Inheritance through the cell’s bodies
Autosomal inheritance
True or False: Chromosomes are made up of one single DNA molecule that runs several thousands of kilobases.
True
Chromosomes run in _____________ pairs of DNA.
kilobase
The discovery of chromosomal inheritance which is the main factor present in the chromosome passed on from one generation to the next serving as the basis of modern hereditary concepts was not discovered until the discovery of _______________________.
DNA’s double helical structure (by Watson and Crick)
True or False: Early experiments, like an experiment on rats to isolate chromosomal DNA as the main factor that Mendel was looking at, occurred even before the Watson and Crick era. However, they were not yet sure about the structure of DNA during the chromosomal analysis of these individuals until the Watson-Crick era.
True
In the chromosomal factors studied by Flemming, there were two biomolecules present that are candidates of transmission of genetic material from one cell to the other, which are… (2)
DNA
Protein
What are the factors that distinguish one species from another?
Chromosomes
The early experiment being the first to prove that it is in fact DNA that is being passed from one generation to the next, and not protein.
R and S Strain
As diploid individuals, there are how many DNA strands that make up our individual chromosomes, where the number and sets of genes present in the chromosomes are what distinguishes one species from another?
46
The number of stained regions or euchromatin stained, indicates the number of…. (2)
The number of stained regions or euchromatin stained, indicates the number of…. (2)
We lack the __________ protein, which is seen in hedgehogs, as the genes present in our chromosomes dictate what proteins are expressed.
Quill
As we move towards the molecular side of Genetics, we don’t just look at chromosomes and karyotypes now. Instead, we analyze __________________ (2) in the chromosomes that dictate speciation.
microscopic aberrations
molecular changes
What would distinguish humans from chimpanzees, even though we have a very close number of chromosomes?
Replication of certain portions of genes having an increased number of genes
In the previous years, what was the important facet of staining chromosomes?
Banding patterns of heterochromatin and euchromatin (genetically-transcriptionable areas)
What is genetically-transcriptionable, heterochromatin or euchromatin?
Euchromatin
The double-helix DNA is wrapped and poled around what proteins to create a chromosome?
Histone proteins
The chromosome is tied together in the center or a constriction in the middle, which refers to the…
Centromere
True or False: All chromosomes have centromeres.
False
What dictates the type of chromosome? (3)
- Presence and absence of centromere
- Quantity of centromere
- Position of centromere
The _____________ is when they are a pair of sister chromatids tied together at the centromere and where microtubules attach and divide.
Rule of Centromere
Enable transmission of genetic information from one generation to the next
Chromosome
In this process, sister chromatids contain the same information in one cell.
Mitosis
The number of sets of chromosomes in a cell from one generation to the other.
Ploidy
True or False: Changes in the number of chromosomes from one generation to the other spells out consequences prominent in cancer patients where chromosomal aberrations occur in the products of mitosis because of the rapid and uncontrolled cell division in the tumor.
True
In meiosis, this enables each mature ovum and sperm to contain a unique single set of parental genes.
Chromosomes
In meiosis, chromosomes go from 2n _______________ to n ______________.
diploid –> haploid
Genetic Recombination is seen in what stages of Meiosis?
Prophase I
Chromosomes in meiosis encapsulates the idea of what theory?
Law of Independent Assortment and Segregation
These are the chromosomes that are constant in the body.
Autosomes
Mitochondrial DNA are attributed to _____________________ such as MELAS.
extra-chromosomal DNA
True or False: Meiosis recombination confound in these phases create new genetically different individuals from their parents that improve our immune system and survive diseases that our parents cannot.
True
How many autosomes do humans have?
44 chromosomes
These are the other DNA materials found in mitochondria.
Extra-chromosomal DNA
How many sex chromosomes do humans have?
2 chromosomes
We only get from our mothers
Matrilineal
Diseases develop through _________________ and __________________ in the mitochondrial DNA
heteroplasmy; mosaicism
These are the regions at the end of linear chromosomes (eukaryotes).
Telomeres
Each cell contains how many pairs of human chromosomes?
23 chromosomes
What is the molecule of life?
DNA
The part of the chromosome that plays a role in attaching cells to nucleolus during meiosis.
Telomeres
Each cell contains how many human chromosomes?
46 chromosomes
Approximately how many genes code for proteins that perform most life functions?
20,000 to 25,000
Approximately how many DNA base pairs per set of chromosomes containing the bases A, T, G and C are there?
3 billion
Replicated condensed chromosome with sister chromatids
Metaphase Chromosome
Describe the Metaphase Chromosomes. (2)
Replicated
Condensed
What is the most condensed form of the chromosome?
Metaphase Chromosome
What is the most studied chromosome because this is the most condensed form?
Metaphase Chromosome
What part of the chromosome becomes prominent in the metaphase plate?
Centromere
True or False: Telomeres are found in circular chromosomes (prokaryotes)
False
Linear Chromosomes are found in what organisms?
Eukaryotes
Circular chromosomes are found in what organisms?
Prokaryotes
Protect the chromosomes from being destroyed at the tips; Genetic information at the end might still be helpful for the process of life
telomeres
The part of the chromosome that helps in the maintenance of information encoded in the DNA.
Telomeres
True or False: Telomere protects the loss of genetic information and helps in non-development of tumors.
True
Enzyme the synthesized the telomere ensures that the information until the very end of the chromosome remains
Telomerase
True or False: Karyotyping is important in chromosome arrangement.
True
The pairing in karyotyping is arranged according to…
Size
What is the biggest chromosome?
X Chromosome
What is the smallest chromosome?
Y Chromosome
DNA is wound around histones to form __________________. These are organized into __________________, which in turn make up the ___________________.
nucleosomes; solenoids; chromatin loops
This protein is rich in basic amino acids (Arginine and Lysine) for positive charges to be present in order to attract phosphate.
Histones
Histones are rich in what basic amino acids? (2)
Arginine and Lysine
Arginine and Lysine are what types of amino acids?
Basic
Histone protein is rich in basic amino acids (Arginine and Lysine) for positive charges to be present in order to attract _______________.
phosphate
The protein that is composed of an octamer, which is an eight-molecule plus 1.
Histone
What is the plus 1 in the octamer histone protein?
H1 Protein
What is the closer of the loop of DNA in histones?
H1
H1 protein is located at the…
periphery
Beads on a string, like a rosary that creates a three-dimensional zigzag structure via Histone H1 and other DNA-binding proteins
Nucleosome
The bead-like structure of nucleosome is composed of how many globular proteins?
8 globular proteins
Nucleosome becomes a three-dimensional zigzag structure via what structures?
H1 Histone and DNA-binding proteins
Helper proteins are also called…
Anchoring proteins
It is the base of the structure that creates a macrostructure that we now see as chromosome
Scaffolding proteins
True or False: Radial loops is the entire chromosome.
False
(just a portion)
Made through the compaction of radial loops
Helper Proteins
This protein acts as a linker that allows the zigzag structure that creates a tighter structure.
H1 Protein
Wrapped around in histone molecule would be how many nucleotide pairs of DNAs?
147
Two identical strands which are the result of DNA replication
Chromatids
Central region of the chromosome
Centromere
Primary constriction where sister chromatids are linked
Centromere
Consists of several hundred kilobases of repetitive DNA
Centromere
Responsible for chromosome movement at cell division
Centromere
The centromere of the chromosome divides the chromosome into… (2)
p arm (Short arm or petite)
q arm (long arm or queues or g = grande)
P arm is also known as the…
Short Arm or Petite
Q Arm is also known as the…
Long Arm or Queue
Q Arm may also be represented by what letter?
G = Grande
Organelle located at the centromere region
Kinetochore
The part of the chromosome that possesses the Microtubule Organizing Center.
Kinetochore
This facilitates spindle formation.
Kinetochore
What are the two regions of kinetochores?
Inner Kinetochore
Outer Kinetochore
The region of the kinetochore which is tightly associated with the centromere DNA.
Inner kinetochore
The region of the kinetochore which interacts with microtubules.
Outer Kinetochore
The tip of each chromosome.
Telomere
The telomere is composed of tandem repeats of hexameric sequence. What is that sequence?
‘TTAGGG’
The loop of underwoman that would create the structure that allows for the elongation of the telomeric region.
Laureat Formation
What is the type of sequence (‘TTAGGG’) of the telomere?
hexameric
True or False: Telomerase has some factor of being a reverse transcription enzyme.
True
What are the functions of telomeres in preserving chromosome stability? (4)
○ 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: Faster loss of telomeres is correlated with a higher risk for mutations and cancer.
True
Telomeres are correlated with what factors? (5)
- the size of the animal
- how fast it multiplies its cells
- faster metabolism
- lifespan
- cell cycles (usually small animals)
The theory that says cells can multiply for only 60 times due to telomere shortening.
Hayflick’s Theory or Model
Hayflick’s Theory or Model states that cells can only multiply for how many times due to telomere shortening?
60 times
What are the types of chromosomes based on the number of centromeres?
- Monocentric
- Acentric
- Dicentric
This chromosome has a single centromere only; Reliably transmitted from parental to daughter cells
Monocentric
What is the only normal kind of chromosome according to number of centromeres?
Monocentric
The type of chromosome that is genetically unstable because they cannot be maneuvered properly during cell division and are usually lost.
Acentric
The chromosome that is not passed from one generation to the other.
Acentric
The type of chromosome with two centromeres.
Dicentric
The type of chromosome that is genetically unstable because it is not transmitted in a predictable fashion.
Dicentric
entromere is centrally located in these types of chromosomes.
Metacentric
What are the types of chromosomes based on centromere position?
- Metacentric
- Submetacentric
- Acrocentric
- Telocentric
The type of chromosome with centromere in the middle, yielding arms of roughly equal length.
Metacentric
The arms of metacentric chromosomes are… (equal or unequal)
roughly equal
How many metacentric chromosomes does humans have?
5 pairs
True or False: All of the chromosomes in a karyotype would have a distinguishable q and p arm.
False
The type of chromosome with an off-center centromere.
Submetacentric
What arm is longer in the submetacentric chromosome?
Q Arm
The arms of submetacentric chromosomes are… (equal or unequal)
unequal
How many pairs of submetacentric chromosomes does humans have?
13 pairs
True or False: The unequal length of the arms of chromosomes makes it easier to determine the type of arm.
True
The chromosome with a centromere that is very close to one end.
Acrocentric
Acro means…
peak
True or False: Acrocentric chromosomes yield a very small short arm.
True
Acrosomes are often associated with small pieces of DNA called _____________, encoding ___________.
satellites; rRNA
The type of chromosome often associated with small pieces of DNA called satellites, encoding rRNA.
Acrocentric
How many pairs of acrocentric chromosomes does a human have?
5 pairs
Acrocentric chromosomes also have a p arm region that is extremely small, they are called ___________________ instead.
Satellite Regions
True or False: Satellites of Acrocentric Chromosomes do not contain important genetic information.
False
One of their functions is the encoding of rRNA that helps in the overall structure of ribosomes, which are the key in translation.
Satellite Regions
What creates ribozymes?
rRNA
Protein
rRNA + protein creates…
Ribozymes
The Y chromosome is what type of chromosome?
Acrocentric
What is the shape of a metacentric chromosome?
V Shape
What is the shape of a submetacentric chromosome?
J Shape
What is the shape of an acrocentric chromosome?
I Shape
In this type of chromosome, the centromere is found at the terminal end.
Telocentric
What is the type of chromosome not found in humans?
Telocentric
Telocentric chromosomes are mostly found in…
plants (weird ploidies—polyploids like in potatoes)
What is the symbol for subtelocentric chromosome?
St
What is the symbol for metacentric chromosome?
M/m
What is the symbol for submetacentric chromosome?
Sm
What is the symbol for acrocentric chromosome?
T
What is the arms length ratio for metacentric chromosomes?
1.0-1.6/1.7
What is the arms length ratio for subtelocentric chromosomes?
3.1-6.9
What is the symbol for telocentric chromosome?
T
What is the arms length ratio for submetacentric chromosomes?
3.0
What is the arms length ratio for acrocentric chromosomes?
7.0
What is the arms length ratio for telocentric chromosomes?
not applicable
The shorter the p arm, the ____________ the number/ratio becomes.
bigger
An important region of the eukaryotic linear chromosome
Telomere
Telomere
Telomeres
This is an enzyme that lengthens the telomeres.
Telomerase
In mitosis, this ensures that the daughter cell retains its own complete genetic complement.
Chromosome
