WEEK 2: INTRODUCTION TO CYTOGENETICS Flashcards
Branch of science that deals with the study of CELLS in terms of structure, function, and chemistry.
CYTOLOGY
This is the study of inherited traits, rooted in DNA, and their variations, and transmission.
GENETICS
This is the transmission of traits and biological information between generation.
HEREDITY
Units of heredity in that copies of genes are passed from one generation to the next. This is the transmission of inherited traits, segments of chromosome which contain genetic information.
GENES
A gene is composed of the molecule ________, more familiarly known as ____
DEOXYRIBONUCLEIC ACID
DNA
DNA is a very long protein molecule that is composed of base pairs called “________” arranged on a structure of phosphate and deoxyribose.
NUCLEOTIDES
The complete set of genetic instructions characteristic of an organism, including protein-encoding genes and other DNA sequences.
GENOME
They contain all the genetic information necessary to create a living being. These are dense bodies found in the nucleus of cells.
CHROMOSOME
Our chromosome contain the entire “________” for all human life.
BLUEPRINT
Chromosomes were discovered by ________ in 1842 using plants.
KARL WILHELM VON NAGELI
________ described chromosomes using salamander.
WALTHER FLEMMING
________ coined the term chromosome.
HEINRICH WALDEYER
Two (2) arms - called the “________” of the chromosome.
SHORT ARM / P ARM
Two (2) legs - called the “________” of the chromosome.
LONG ARM / Q ARM
Chromosomes are joined in the middle via the ___________
CENTROMERE
Chromosomes usually jumbled and mixed-together in the ________ of cells
NUCLEUS
All full complement chromosomes arranged from the largest to smallest called a “________.”
KARYOTYPE
____ chromosomes in human cells.
46
____ autosomal pairs (one of each type is contributed by the mother and one of each type contributed to the father.)
22
____ sex chromosomes
2
Humans have roughly ________ to ________ genes.
20,000 TO 35,000
Alternative forms of gene and is more specific.
ALLELES
Expressed when present (even in one copy). Represented by capital letters (e.g., B)
DOMINANT ALLELES
Expressed only when two copies are present. Represented by lowercase letters (e.g., b)
RECESSIVE ALLELES
- Genetic makeup of an organism. This is the genetic composition of a particular trait.
- It has less influence of environmental factors and it is not observable.
- It remains the same throughout the lifetime.
- It is not influenced by the phenotype.
GENOTYPE
- Observable characteristics. This is the physical expression of a particular trait.
- It has high influence of environmental factors and it is observable.
- It may change with time.
- It is influenced by the genotype.
PHENOTYPE
There are several main functions that the cell must carry out:
- MOLECULE TRANSPORT
- ENERGY CONVERSION
- REPRODUCTION
Two types of cells.
- PROKARYOTIC CELL
- EUKARYOTIC CELL
Simpler, smaller than a eukaryotic cell, lacking of nucleus and most of the other organelles of eukaryotes.
PROKARYOTIC CELL
Nuclear material consist of a ____________ which is in direct contact with cytoplasm.
SINGLE CHROMOSOME
This is the undefined nuclear region, where the DNA is condensed in the cytoplasm.
NUCLEOID
15 times wider than a typical prokaryote and can be as much as 1000 times greater in volume.
EUKARYOTIC CELL
Eukaryotic cell contain ________________ in which specific metabolic activities take place.
MEMBRANE-BOUND COMPARTMENTS
Most important in eukaryotic cells.
NUCLEUS
A membrane delineated compartment that houses the eukaryotic cells DNA.
NUCLEUS
Nucleus gives the eukaryote as “________.”
TRUE CELL
Eukaryotic DNA is organized in one or more linear molecules called __________
CHROMOSOMES
Branch of genetics studying inheritance related to chromosome structure and function.
CYTOGENETICS
Cytogenetics focuses on ________ and ________
- CHROMOSOMAL ABERRATIONS
- ABNORMALITIES
Cytogenetics involves the study of ________, ________, and ________.
- NUCLEIC ACIDS
- CHROMOSOME STRUCTURE
- GENES
Branches of Genetics
- CLASSICAL GENETICS
- POPULATION GENETICS
- MOLECULAR GENETICS
- QUANTITATIVE GENETICS
Discipline that describes how physical characteristics (traits) are passed along from one generation to another.
CLASSICAL GENETICS
The study of genes in populations of animals, plants, and microbes provides information on past migrations, evolutionary relationships and extents of mixing among different varieties and species, and methods of adaptation to the environment.
POPULATION GENETICS
The study of the chemical and physical structures of DNA, its close cousin RNA (ribonucleic acid), and proteins. ____________ also covers how genes do their jobs.
MOLECULAR GENETICS
A highly mathematical field that examines the statistical relationships between genes and the traits with which they are associated.
QUANTITATIVE GENETICS
Genetic concepts have been found in the literature of the Greeks. “The Greeks were tied with the idea of heredity because of the constant referral to lineages of kings and gods.”
BAZOPOULOU - KYRKANIDOU
Proposed that “humors” served as bearers of traits.
ARISTOTLE (350 BC)
Proposed the theory of epigenesis, which states that an organism develops from the fertilized egg by a succession of developmental events that eventually transform the egg into an adult.
WILLIAM HARVEY (1600)
Around 1830, they proposed the cell theory, stating that all organisms are composed of basic structural units called cells, which are derived from pre-existing cells.
MATTHIAS SCHLEIDEN AND THEODOR SCHWANN
In 1859, ____________ published On the Origin of Species, describing his ideas about evolution. ________ thinking led him to formulate the theory of natural selection, which presented an explanation of the mechanism of evolutionary change.
DARWIN
In 1866, history of genetics is generally held to have started with the work of an Augustinian friar, ____________. He is also known as the Father of Genetics. His work on pea plants described what came to known as the Mendelian Inheritance.
GREGOR MENDEL
Formulated the theory of Natural Selection.
CHARLES DARWIN
It states that individuals with heritable traits that allow them to adapt to their environment are better able to survive and reproduce than those with less adaptive traits.
NATURAL SELECTION
Published a paper describing how traits are passed from one generation to the other, utilizing pea plants as models. He also proposed that traits are passed from parents to offspring in a predictable manner. He further concluded that each trait in pea plants is controlled by a pair of factors (which we now call genes) and that members of a gene pair separate from each other during gamete formation (the formation of egg cells and sperm).
GREGOR MENDEL
In nature, ____________ typically selffertilize, fertilizing over with their own sperm.
PEA PLANTS
Each pea plant has male (________) and female (________) sexual organs
STAMEN AND CARPAL
1900 - “Rediscovery of Mendel” by ____________, ________________ and ________________ (Mendelian Law of Inheritance)
- HUGO DE VRIES
- CARL CORREMS
- ERICH VON TSERMAK
Early 20th century - ____________ and ____________ in the advent of advances in microscopy proposed that genes are carried on chromosomes - Basis of the Chromosome Theory of Inheritance.
- WALTER SUTTON
- THEODORE BOVERI
On 1905, he coined the word “genetics” for the first time and that made genetics as a formal branch of biology. It was also the same year that ________ along with Punnett (Punnet square), made a significant findings on genetic linkages.
WILLIAM BATESON
1915 - basic principles of Mendelian genetics had been applied to a wide variety of organisms – most notably the fruit fly, ________________
Drosophilia melanogaster
1925 - led by ____________ and his fellow drosophilists, geneticists developed the Mendellian chromosome Theory of Heredity.
THOMAS HUNT MORGAN
____________ is dependent on the genes contained in the structures called chromosomes. The chromosomes were contributed to the individual by the gametes.
HEREDITY
The characteristic number of chromosomes a eukaryote has in most of its cells.
DIPLOID NUMBER (2n)
Chromosomes in diploid cells exist in pairs called ____________.
HOMOLOGOUS CHROMOSOMES
Chromosomes behave differently during the two
forms of cell division, ____________ and ____________.
MITOSIS AND MEIOSIS
In ________, the chromosomes are copied and distributed to each daughter cell. Both cells obtain a ________ set of chromosomes.
MITOSIS ; DIPLOID
In ________, the cells receive only one chromosome from each chromosome pair, and the resulting number of chromosome is called the ____________.
MEIOSIS ; HAPLOID NUMBER (n)
The ________________ states that “inherited traits are controlled by genes residing on chromosomes faithfully transmitted through gametes, maintaining genetic continuity from generation to generation.”
CHROMOSOMAL THEORY OF INHERITANCE
Simple chromosome organization of fruit fly.
3 PAIR OF AUTOSOMAL
CHROMOSOME AND PAIR OF SEX CHROMOSOMES
Genes were known to exist on chromosomes, chromosomes are composed of both protein and DNA – scientist did not know which of these is
responsible for inheritance.
1920
On 1928, he discovered the phenomenon of transformation: dead bacteria could transfer genetic material to “transform” other still-living bacteria.
FREDERICK GRIFITH
On 1944, they identified the molecule responsible for transformation as DNA.
- OSWALD THEODORE AVERY
- COLIN MCLEOD
- MACLYN MCCARTY
On 1952, ________ and ________ experiment also showed that DNA (rather than protein) is the genetic material of the viruses that infect bacteria, providing further evidence that DNA is the molecule responsible for inheritance.
- ALFRED HERSHEY
- MARTHA CHASE
On 1953, ________ and ________ determined the structure of DNA, using the X-ray crystallography work of Rosalin Franklins that indicated DNA had a helical structure.
- JAMES D. WATSON
- FRANCIS CRICK
On 1958, ________ and ________ used the equilibrium density gradient centrifugation to conclude that DNA replication is semiconservative.
- MESELSON
- STAHL
On 1985, ________ pioneered discussions to sequence the human genome.
ROBERT SINSHEIMER
On 1986, ________ developed the Polymerase Chain Reaction.
FRED SANGER
On 1996, ____________ was born – first ever cloned animal from an adult somatic cell using the process of nuclear transfer - __________________
- DOLLY THE SHEEP
- IAN WILMUT
Four main evolutionary processes.
- NATURAL SELECTION
- GENETIC DRIFT
- MUTATION
- GENE FLOW
A set of organism in which any pair of members can breed together. This implies that all members belong to the same species and live near each other.
POPULATION
Process by which heritable traits that make it more
likely for an organism to survive and successfully reproduce become more common in a population over successive generations.
NATURAL SELECTION
The change in relative frequency in which a gene variant (allele) occurs in a population due to random sampling and chance.
GENETIC DRIFT
Changes in the DNA sequence of a cell’s genome maybe caused by radiation, viruses, transposons, and mutagenic chemicals, as well as errors that occur during meiosis or DNA replication.
MUTATION
Exchange of genes between populations which are usually of the same species.
GENE FLOW
Cytogenetics involves the examination of chromosomes and their abnormalities. Chromosomes of a dividing human cell can be clearly analyzed in white blood cells, specifically T lymphocytes, which are easily collected from blood. Cells from other tissues such as bone marrow, amniotic fluid, and other tissue biopsies can also be cultured for cytogenetic analysis.
CYTOGENETIC TESTING
Clinical testing for a biochemical disease utilizes techniques that examine the protein instead of the gene. Many biochemical genetic diseases are known as ‘inborn errors of metabolism’ since they are present at birth and disrupt a key metabolic pathway.
BIOCHEMICAL TESTING
METHODS OF GENETIC STUDY
- GENETIC MAPPING
- RECOMBINANT DNA TECHNOLOGY
- BIOTECHNOLOGY
Direct DNA analysis is possible only when the gene sequence of interest is known. For small DNA mutations, direct DNA testing may be the most effective methodology, particularly if the function of the protein is not known and a biochemical test cannot be developed.
MOLECULAR TESTING
It can offer form evidence that a disease transmitted from parent to child is linked to one or more genes. Provides clues about the chromosome contains the gene and precisely where it lies on that chromosome. Have been used successfully to find the single gene responsible rare inherited disorders.
GENETIC MAPPING
How do researchers create a genetic
mapping?
- Researchers collect blood or tissue samples from family members where a certain diseases or it prevalent.
- The scientist isolate DNA from these samples and
examine it for the unique patterns of bases seen only in the family members who have diseases or trait. - These characteristic molecular patterns are referred to as polymorphism, or markers.
Researchers discovered ____________ that could be used to cut any organism’s DNA at specific nucleotide sequences, therefore producing a reproducible set of DNA fragments.
RESTRICTION ENZYMES
The recombinant DNA will be transferred into bacterial cells to produce thousand of copies, or ____________.
CLONE
The cloned DNA fragments can be isolated from the bacterial host cells. Such fragments can be used to isolate genes, study their organization and expression, and to study their nucleotide sequence and evolution.
RECOMBINANT DNA TECHNOLOGY
This is the use of recombinant DNA technology and other molecular techniques to make product. It has also changed the way human proteins for medical use are produced.
BIOTECHNOLOGY
The study of genome. It studies the structure, function, and evolution of genes and genomes.
GENOMICS
It identifies the et of proteins present in a cell under a given set of conditions, and studies their functions and interactions
PROTEOMICS
It is the subfield of information technology used to store, retrieve and analyze the massive amount of data generated by genomics and proteomics.
BIOINFORMATICS
Model Organisms iin Genetic Studies
- Principles of inheritance described by Mendel were universal among plants and animals.
- Geneticists gradually came to focus attention on small number of organisms, including the fruit fly (Drosophila melanogaster) and the mouse (Mus musculus)
Practical Application of Genetics
- Establishing identity- forensics, history and ancestry
- Health care- single gene disease (inherited diseases) , genetic testing, treatment
- Agriculture- breeding (biotechnology, transgenic organism)
- Ecology
