Lesson 2 Flashcards
Introduction to Cytology
Branch of genetics that studies the function of the cell, specifically the chromosomes, in the process of inheritance
Cytogenetics
Discovery of chromosomes in plants cells
Karl Wilhelm von Nägeli 1842
Chromosomes in animal cell (salamander)
Walter Fleming
Human karyotype included only how many chromosomes (include year)
46 chromosomes, 1956
Three techniques employed in Cytogenetics
Karyotyping
FISH
DNA microarray technology
Routine analysis of chromosomes at the metaphase stage; most basic technique
Karyotyping
What stage does Karyotyping occur
Metaphase stage
Karyotyping banded using
trypsin
Karyotyping stains after banding using trypsin
Giemsa
Leishman
both
Types of Karyotyping
G-banding
Q-banding
C-banding
NOR stains
Can identify chromosomal aberrations (translocation and rearrangements); useful in creating a karyogram
G-banding
Stain specifically binds to phosphate groups of the DNA and where there is high adenine-thymine bonding
Giemsa banding
A much earlier Fluorescent staining technique
Quinacrine banding
Developed Q-banding in late 1960s
Toborson Caspersson
Stains heterochromatin near the centromere
C-banding
Highlights the satellites and stalks of acrocentric chromosomes
Nucleolar Organizing Region stains (NOR stains)
Cytogenetic technique that uses fluorescent probes that attaches to specific areas in the chromosome with high degree sequence complementarity
Fluorescent In-situ Hybridization
Used to detect and localize the presence or absence of specific DNA sequences in the chromosomes
FISH
Collection of microscopic DNA spots attracted to a solid surface; makes use of a DNA microarray or a DNA chip
DNA microarray analysis
Types of microarray
Traditional solid-phase
Alternative bead array
spots attached to the surface
Traditional solid-phase array
using polyesterene beads each with a specific probe and a ratio of two or more dyes
Alternative bead array
Cytogenetics that diagnosis of heritable genetic abnormalities or de novo
Constitutional (germline) cytogenetics
Cytogenetics that is the detection of acquired or somatic genetic abnormalities
Cancer cytogenetics
postnatal
adolescent
prenatal
fetal/neonatal
Indications of Constitutional
hematologic oncology
bone marrow transplant
Cancer
Organized structures containing the DNA of an organism associated with structural proteins (histones) and some other factors that help maintain its integrity and facilitate its formation and replication
Chromosome
supercoiled DNA structure; may exist as unduplicated or duplicated
Linear Chromosome
Chromosome that appear as lines
Unduplicated
Chromosome that contains chromatids
Duplicated
All living organisms are composed of cells
The Cell Theory
Living organisms come from non-living
Spontaneous generation
Parts of the Cell
Nucleus
Cytoplasm
Nucleus function + parts
Storage of genetic information
-Nuclear envelope
-Chromatin
-Nucleolus
-Nucleoplasm
Powerhouse of the cell; generates ATP
Mitochondria
Long motile hair-like structures
Cilia
Cylindrical cytoplasmic projection of apical surfaces to increase surface area
Microvilli
Tight junction
Adhering Junction
Gap Junction
Intercellular junctions
Synthesis of ribosomes
Transfer vesicles, transfer the formed protein to Golgi
Rough ER
Synthesis of lipids, cholesterol, steroid hormones & detoxification of drugs and toxins
Smooth ER
Sorting, modification & packaging of proteins
Secretory apparatus of the cell
Formation of lysosomes
Golgi apparatus
Digestive apparatus of the cells (intracellular digestion)
Lysosomes
Protein synthesis
Ribosomes
Cell division and formation of cilia and flagella
Centrioles
Movement of particles or fluids on the free surface of the cell in one direction
Cilia
Important for movement of sperms
Flagella
Structural skeleton
- microfilament
-intermediate filaments
-microtubules
Cytoskeleton
Series or the universal pattern and process of cells from birth to reproduction to metabolic activities to death
The Cell Cycle
Four distinct phases
G1
S
G2
M phase
Which goes first, Interphase or Mitosis?
Interphase
Synthesis of amino acids and other biochemical needed for S phase
G1 (Growth phase)
DNA in chromosome are replicated
S (Synthesis)
Synthesis of chemicals needed for production of microtubules
G2
Two sub-phases of Mitosis
Karyokinesis
Cytokinesis
Cell nucleus divides
Karyokinesis
Cell itself divides into daughter cells
Cytokinesis
Nuclear division among somatic cells
Mitosis
How many phases are in Mitosis
Four (PMAT)
What happens in the Interphase of M
Chromosomes are in form of chromatin
DNA begins to supercoil
Chromosomes condense
Prophase
Chromosomes align at the center
Metaphase
Chromatids of each chromosome separated; pull towards opposite poles
Anaphase
DNA begins to diffuse
Chromosomes at poles become more diffuse
Telophase
Division into two daughter cells is complete
Cytokinesis
Nuclear division undergone by germ cells
Meiosis
Meiosis is a double division producing how many daughter cells
FOUR that are HAPLOID
Two processes of Meiosis
Meiosis I
Meiosis II
each chromosome searches for its homologous pair in a process
Homology search
Paired up chromosomes
tetrads or bivalents
Exchange of genetic material bet. non-sister chromatids
Synapsis or intimate pairing
Site of exchange or synapsis
Chiasmata
Prophase I sub-stages
Leptotene
Zygotene
Pachytene
Diplotene
Diakinesis
Individual chromosomes condense within the nucleus
Leptotene
Homologous chromosome pair up during synapsis
Zygotene
Crossing over happens
Pachytene
Chromosomes separate slightly
Diplotene
Spindle fibers form
Nucleolus, envelope gone
Diakinesis
Chromosomes line up
spindle fibers attach to centromeres
Metaphase I
Chromosomes migrate to the poles
Anaphase I
Reductional phase &
Chromosomes are now at poles
Telophase I
Nucleoli, envelope disappear & thickening and shortening of chromosomes
Prophase II
Chromosome migrate at the center
Metaphase II
Sister chromatids are pulled apart from one another
Anaphase II
Chromosomes diffuse into the nucleus
Telophase II
Spermatogenesis for males
four sperms of generally equal potency
oogenesis for females
one large ovum & three polar bodies
