CYTOGEN 1ST TRINAL Flashcards
is the study of inherited traits and
their variation.
Genetics
is the transmission of traits and
biological information between generations,
and genetics is the study of how traits are
transmitted
Heredity
are the units of heredity. Genes are
biochemical instructions that tell cells, the
basic units of life, how to manufacture certain
proteins
Genes
- the basic units of life
Cells
The ______ transmits information in its sequence of four types of building blocks, which function like an alphabet.
A gene consists of this long molecule
DNA or deoxyribonucleic acid
The complete set of genetic instructions
characteristic of an organism, including
protein-encoding genes and other DNA
sequences, constitutes a
genome
resembles a spiral staircase or double
helix.
DNA
are pairs of the four types of
building blocks, or nitrogenous bases: adenine
(A) and thymine (T), which attract each other,
and cytosine (C) and guanine (G).
DNA double helix
the four types of building blocks, or nitrogenous bases:
adenine
thymine
cytosine
guanine
the chains of the double helix
untwist and separate, and then each half
builds a new partner chain from free DNA
bases.
DNA replication
copies the sequence of part of
one strand of a DNA molecule into a related
molecule, messenger ribonucleic acid (RNA).
Transcription
, each three RNA bases in a row
attract another type of RNA that functions as a
connector, bringing in a particular amino acid.
Translation
- A change in a gene, can have an
effect at the whole-person level, such as
causing a disease.
Mutation
- The human genome has about 20,325
protein-encoding genes, and these DNA
sequences comprise it
Exome
– The same protein-encoding gene may
vary slightly in DNA base sequence from
person to person.
Alleles
- The DNA sequences of the
human genome are dispersed among 23
structures.
Chromosomes
A_____________ (non-sex cell) has 23
pairs of chromosomes.
human somatic cell
22 of these 23 human somatic cell pairs are
autosomes
The autosomes are numbered from 1 to
22, with 1 being the
largest.
23rd pair of chromosome is the X and Y
chromosome
(Sex Chromosomes
- Charts display the chromosome
pairs from largest to smallest.
Karyotypes
- A trait caused predominantly by a
single gene
Mendelian
- determined by one or
more genes and environmental factors
Multifactorial traits
– Groups of differentiated cells
assemble and interact with each other
Tissues
- Many organs include rare,
unspecialized stem cells
Stem Cells
- energy & structure (sugars
and starches)
CARBOHYDRATES
- allele has an effect when present
in just one copy (on one chromosome)
Dominant
- allele must be present on both
chromosomes of a pair to be expressed.
Recessive
- depict the members of a family and
indicate which individuals have particular
inherited traits.
Pedigrees
– compares DNA sequences
among individuals to establish or rule out
identity, relationships, or ancestry.
DNA profiling
– means altering a gene
or genome in a way that does not occur in
nature, such as giving a carrot a gene from a
green bean that isn’t part of the carrot
genome.
Genetic modification
can replace, remove, or add
specific genes into the cells of any organism.
Genome editing,
– determines the order of
the DNA bases of all parts of the genome that
encode proteins—that is, about 20,325 genes.
Exome sequencing
o also called body cells
o have two copies of the
genome and are said to be diploid.
o Has 23 PAIRS of chromosomes
Somatic cells
– which are sperm and egg cells,
have one copy of the genome and are haploid.
Germ cells
Tissue Types
connective tissues
epithelial tissue
muscle tissue
nervous tissue
– protect, support, bind to cells, and fill spaces throughout the body
Connective Tissue
– protect, secrete, absorb, and excrete
Epithelial Tissue
– Cells contract, providing movement.
Muscle Tissue
– Neurons transmit
information.
Nervous Tissue
4 Major Macromolecules
carbohydrates
lipids
proteins
nucleic acid
- energy & structure
(sugars and starches)
CARBOHYDRATES
- hormones, insulation, energy
storage (fats and oils)
LIPIDS
- clotting, bulk of connective
tissue & enzymes (albumin, amylase)
PROTEINS
- cell characteristics
(DNA and RNA)
NUCLEIC ACIDS
3 Major Domains of Life
o Archaea - unicellular
o Bacteria – unicellular
o Eukarya - multicellular
o All organisms are made up of one or
more cells
CELL THEORY
Main components of the cell:
o Nucleus
o Plasma membrane
the outermost layer
separating contents from the
external environment
selectively permeable
bilayer of lipoprotein
Plasma membrane
the fluid or matrix content inside
the plasma membrane of a cell
along with the cell organelles
Cytoplasm
The most prominent organelle of
most cells.
Nucleus -
– a layer that surrounds the
nucleus.
Nuclear envelope
– inner face of the
nuclear membrane, provides
mechanical support and holds the
nuclear pores in place.
Nuclear lamina
– exit and entrance of the
nucleus
Nuclear pore
- (“little nucleus”). Ribosomes are
produced.
Nucleolus
o the “powerhouse of the cell”
o biochemical process of respiration and
energy production occur
Mitochondria
o storage sacs for solid or liquid contents
bounded by a unit membrane
o animals: many = small
o plants: few = large
Vacuoles
o large network of membrane bound
tubes and sheets “quality control
center”
Endoplasmic Reticulum
o site of protein synthesis
o Studded with ribosomes
Rough Endoplasmic Reticulum
o Synthesis of lipids, steroid hormones
and detoxification of harmful products
Smooth Endoplasmic Recitulum
o “stack of pancakes” (4-6
interconnected flat membranes)
o responsible for correctly shipping the
proteins produced in the ER
o cisternae = the folds
Golgi Apparatus
o active site for protein synthesis
o perform biological protein synthesis
(mRNA translation)
Ribosomes
– the release of a substance from a
cell
Secretion
o contains digestive enzymes (43)
o functions as the cell’s recycling
compartment
o examples: Macrophages and liver cells
o “bodies that cut”
Lysosomes
o rigid outer covering of plant cells
(plants, fungi, and bacteria)
o Mainly composed of cellulose
o Cellulose = plants, chitin = fungi
Cell Wall
o found in plant cells only; double layered
containing their own DNA and
ribosomes
o Chloroplasts - containing green
chlorophyll giving green color
o Leucoplasts - white or colorless plastids
(can change)
o Chromoplasts – colored plastids
Plastids
o microscopic network of protein
filaments and tubules
o maintains cell shape, anchors
organelles, assists with transport (1)
microfilaments, (2) microtubules (3)
intermediate filaments
Cytoskeleton
(smallest filament)
cell movement, muscle
contraction, and cell division.
flexible and relatively strong
Microfilaments
(major component)
stiff and resist bending forces
Microtubules
helping cells maintain their
shape and integrity.
Intermediate Filaments
Vesicle
o membrane-bounded sac
o temporarily stores or transports
substance
Vesicle
Exosomes
o remove debris, transport immune
system molecules, and provide vast
communication network among cells
o bud from one cell and then travel to,
merge with, and empty their contents
into other cells
Exosomes
o sacs with single outer membranes
studded with several types of proteins
containing enzymes
o breaks down and detoxifies various
molecules
Peroxisome
o A enzyme is deficient that normally
breaks down lipids in the cells that
surround the nerve cells (buried in
lipids)
o effects: infant losing skills (sight,
hearing, mobility)
o Even before birth, lysosomes of
affected cells swell
o Death typically within 3 years
Tay-Sachs Disease
describes the sequence of
activities as a cell prepares for and undergoes
division.
Cell cycle –
2 major stages of cell division
o Interphase
o Mitosis
o Division of somatic cells
o Diploid
Mitosis
o Creation of new sex cells
Meiosis
– Stage of the cell cycle when a cell
is not dividing
- it is divided into two gap (G1 and G2)
phases and one synthesis (S) phase.
Interphase
– The long strands of chromosomal
material in replicated chromosomes.
Chromatid
– The largest constriction in a
chromosome, located at a specific site in each
chromosome type.
Centromere
– The space between sister chromatids
Furrow
A diploid cell will always give rise to a diploid
cell
Chromosome number remains the same
The DNA remains identically the same
Once cell (2N) give rise to two new cells (2N)
MITOSIS
Cell death
Apoptosis –
- During prophase, the first stage of
mitosis, DNA coils tightly. This coiling shortens
and thickens the chromosomes, easing their
separation.
Prophase
– The stage of mitosis when
chromosomes align along the center of the
cell
Metaphase
– Stage of mitosis when the
centromeres of replicated chromosomes part.
Anaphase
the stage of mitosis or meiosis
when daughter cells separate
Telophase -
A chromosome tip.
Telomere –
– short arm of the chromosome
o P
– long arm of the chromosome.
o Q
Two types of proteins, the _____________
interact inside cells, activating the genes
whose products carry out mitosis
cyclins and kinases,
o Chemical signals that control the cell
cycle from outside.
o made in a gland and transported in the
bloodstream to another part of the
body, where it exerts a specific effect.
Hormones
o Sperm and oocytes are, or sex cells.
o Produced in the reproductive system.
o Gametes contribute 23 different
chromosomes, constituting one copy of
the genome, to a fertilized ovum.
o One member of each pair comes from
the person’s mother and one comes
from the father.
Gametes -
- where the sperm and oocytes are
manufactured
Gonads
– develop 125-meter-long
seminiferous tubules, which one researcher
describes as “a massive tangle of spaghetti.”
Sperm Cells
– the seminiferous tubules are packed
into paired, oval organs.
Testes
Ovaries - The female sex cells develop in paired
organs in the abdomen.
Ovaries -
form from special cells, called
germline cells, in a type of cell division called
meiosis that halves the chromosome number.
Gametes
– which means that they have
only one of each type of chromosome.
(gametes)
Haploid (1n)
– with two copies of each
chromosome type. (Somatic Cells)
Diploid (2n)
o “homologs”
o The chromosome pairs
Homologous pairs
2 divisions of meiosis
o Reduction division (Meiosis I)
o Equational division (Meiosis II)
It reduces the number of
replicated chromosomes from
46 to 23.
Reduction division (Meiosis I)
produces four cells from the two
cells formed in the first division
by splitting the replicated
chromosomes.
Equational division (Meiosis II)
– the formation of sperm
cells, begins in a diploid stem cell called a
spermatogonium.
Spermatogenesis
A _______, which is a mere 0.006 centimeter
(0.0023 inch) long, must travel about 18
centimeters (7 inches) to reach an oocyte.
sperm
Each _______ consists of a tail, body or
midpiece, and a head region.
sperm cell
– Meiosis in the female (egg
making), begins with a diploid cell, an
oogonium
Oogenesis
The primary oocyte divides into two cells: a
small cell with very little cytoplasm, called a
first _________
polar body
o Single-gene diseases such as HD and
cystic fibrosis (CF) affect families in
patterns
o Rules that explain the common
patterns of single-gene transmission,
and are derived from Mendel’s laws.
Modes of Inheritance
– which means that
it affects both sexes and appears every
generation.
Autosomal dominant (HD)
– which means that
the disease affects both sexes and can “skip”
generations through carriers, who do not have
symptoms.
Autosomal recessive (CF)
– Single-gene traits and diseases, also called “Monofactorial.”
“Mendelian”
– first derived the two laws of
inheritance that determine how these traits
are transmitted from one generation to the
next.
Gregor Mendel
- Heritable feature that varies
among individuals. (General)
Character
– Pertains to each variant for a character.
Example: Character is a Color, identifying a
color is the trait.
Trait
– parents producing an
offspring with the same phenotype. (Same
traits, same phenotype, same visible
appearance from your parents.)
True breeding
– mating or crossing of two
varities. (inherited either the two or there is a
crossing between two varities.)
Example: white or black, or white + black = gray
Hybridization
parental generation; true breeding parents
P –
– First filial generation; offspring of the
parental cross
F1
– second filial generation; offspring allow to
pollinate or cross one another
F2
– genetic composition of an
organism
Genotype
– the visible information of an
organism contained inside a gene
Phenotype
specific; fix position
Locus –
– alternative form of a gene
Allele
– a nucleotide sequence coding a
polypeptide sequence which makes an
enzyme or structural protein
Gene
– organism having a pair of
identical allele at a given locus at a given
chromosome
Homozygous
– organism having two different
alleles at a given locus
Heterozygous
One trait that masks another
Dominant –
masked trait
Recessive –
– Mendel conducted up to
70 hybrid self-crosses for each of the seven
traits. This experiment is called a _____________because it follows one trait and the self-crossed plants are hybrids.
Monohybrid cross
o Mendel’s idea that element separate in the gametes.
o Mendel’s first law
Law of Segregation
An individual with two identical
alleles for a gene
Homozygous
- An individual with two different
alleles is ___________—what Mendel called
“non-true-breeding” or “hybrid.”
Heterozygous
describes the organism’s alleles
Genotype
– describes the outward expression
of an allele combination.
Phenotype
– Is the most common
expression of a particular allele combination in
a population.
o The wild type allele may be recessive or
dominant.
Wild type phenotype
– Is a variant of a gene’s
expression that arises when the gene
undergoes a change, or mutation
Mutant phenotype
- Crossing an individual of unknown
genotype with a homozygous recessive
individual
Test Cross
– represents how genes in
gametes join if they are on different
chromosomes. Experimental crosses yielded
numbers of offspring that approximate these
ratios.
Punnet square
Law of independent assortment – states that
for two genes on different chromosomes, the
inheritance of one gene does not influence
the chance of inheriting the other gene. The
two genes are said to “independently assort”
because they are packaged into gametes at
random
MENDEL’S SECOND LAW
– A genotype (allele
combination) that causes death is, by strict
definition, lethal.
Lethal allele combinations
– Mendel’s laws can appear not to
operate when one gene masks or otherwise
affects the phenotype of another.
Epistasis
– Different alleles that are both
expressed in a heterozygote
Codominant
– the heterozygous
phenotype is intermediate between that of
either homozygote.
Incomplete dominance
– only one allele is
expressed; the other is not
Complete dominance
A single-gene disease with many
symptoms, or a gene that controls several
functions or has more than one effect
Pleiotropic –
– refers to the percentage of
individuals who have a particular genotype
who have the associated phenotype.
Penetrance
– Mutations in different
genes that produce the same phenotype
Genetic Heterogeneity
– An environmentally caused trait
that appears to be inherited
Phenocopy
are the building
blocks of DNA. Each nucleotide consists of
three components: a sugar molecule
(deoxyribose), a phosphate group, and a
nitrogenous base.
Nucleotides
In DNA, adenine
(A) always pairs with thymine (T), and guanine
(G) always pairs with cytosine (C). This is known
as
Complementary Base Pairing:
form between the complementary base pairs,
holding the two DNA strands together. Adenine forms two hydrogen bonds with thymine, while guanine forms three hydrogen bonds with cytosine.
Hydrogen Bonds
- DNA replication
is a process where the two strands of the DNA
double helix unwind and separate. Each
original strand serves as a template for the
synthesis of a new complementary strand. This
process is called semiconservative replication
because each new DNA double helix conserves
half of the original DNA.
Semiconservative Replication
– A replication fork is a site
where DNA is locally opened and resembles a
fork. It’s where the DNA strands separate,
allowing the replication process to occur.
Replication Fork
is an enzyme that unwinds
the DNA double helix by breaking the hydrogen
bonds between the complementary base pairs.
Helicase
is an enzyme responsible for synthesizing new DNA strands by adding complementary nucleotides to the template strands during replication.
DNA polymerase
– During DNA replication, there are two strands being synthesized. The leading strand is synthesized continuously in the 5’ to 3’ direction, while the lagging strand is synthesized in short fragments called Okazaki fragments, which are later joined together.
Leading Strand and Lagging Strand
is an enzyme that adds a
short RNA primer to the DNA template strands,
providing a starting point for DNA polymerase
to begin synthesis.
Primase
is an enzyme that joins the
Okazaki fragments on the lagging strand,
sealing the gaps between them to create a
continuous strand.
Ligase
– DNA
replication is considered semidiscontinuous
because the leading strand is synthesized
continuously, while the lagging strand is
synthesized in short, discontinuous fragments.
Semidiscontinuous Replication
o DNA coils around proteins called
_______ forming structures that
resemble beads on a string. A DNA
“bead” is called a nucleosome.
Histones
– (Mitosis) discovered
Human Chromosomes
1882 Walther Flemming
– introduced chromosome
1888 Von Waldeyer
– Spermatogonia (47) and oogonia (48)
1912 Hans Von Winiwater
1956 – Clinical Cytogenetics
1956
1977 – ISCN Organization (international
System for Human Cytogenetic Nomenclature)
1977
– the study of genes,
mutations and phenotypes
o Deals with the arrangement of genes on
the chromosome, methods that
generate mutations and various
patterns of inheritance
Classical Genetics
o The proponent for inheritance
o Published the basic rules of inheritance
(1886)
o Hypothesized that traits such as pod
color were controlled by genetic
elements
o Predicted that adult organisms have a
diploid state; gametes are in haploid
state
o Formulated 2 general laws of
inheritance:
Gregor Mendel
– states that if there is presence of
dominant gene or dominant
allele, it will exhibit in the
phenotypic characteristic and
will dominate your recessive
gene.
Laws of Dominance
– there is a
separation of genes/traits and
you will only receive one, each
from your parents.
Laws of segregation
– if you inherited a
certain gene, the other
gene/trait inherited will not be
affected because they are
independent from each other.
Laws of independent
assortment
– chromosome analysis using
karyosome chart, the process is called
“KARYOTYPING”
Karyosome
