Exam 3 Flashcards
What is a zygote
The fertilized egg that develops into a new individual
Mosaicism
The presence of a genetically distinct cell populations within an organism
Gametes
Unfertilized germ cells
Sperm
Male gamete ( sex cell)
Oocyte
Female gamete ( sex cell)
Gonads
Organs where gametes are produced
Testes
Male gonads that produce spermatozoa and male sex hormones
Ovaries
Female gonads that produce oocytes and female sex hormones
Spermatogonia
The initial cells in spermatogenesis
Primary spermatocyte
Are produced by spermatogonia by mitosis
Follicle
In the ovary a developing egg is surrounded by an outer layer of follicles cells
Ovulation
Release of a secondary coyote from the follicle
Usually occurs monthly during a female reproductive lifetime
Oogenesis
The process of oocyte production
Oogonia
Cells that produce primary oocytes by mitotic division
Blastocyst
Hollow ball of cells
Trophoblast
Outer layer of cells
Inner cell mass
A ball of cells found inside the trophoblast that ultimately form the embryo
Endometrium
Enlarges and fills with blood/blood vessels
Chorion
Protective membrane form around the embryo
Human chorion gonadotropin
The main hormone that prevents rejection and are detected by home pregnancy tests.
Oxytocin
Stimulates muscular contractions, dilates the cervical opening and prepares mothers for birth
Breech birth
When another part of the body enters the birth canal other than the head
Teratogen
Any physical or chemical agent that brings about an increase in congenital malformation
Radiation, viruses, medications, alcohol
Fetal alcohol syndrome (fas)
A group of alcohol related birth defects that include physical and mental preambles
Sex ratio
The proportion of male to females, which changes throughout the life cycle
SRY gene
Sex determining region of the Y chromosomes
Located hear the end of the short arm of the Y chromosome
Complete androgen syndrome (CAIS)
An x-linked genetic trait that causes xy individual to phenotypic female
Swyer Syndrome
externally unambiguous female body but with dysgenetic, atypical, or abnormal gonads.
Gonadal Intersexuality
Broad term with many variations between male and female
5 alpha reductase deficiency
An autosomal genetic condition that causes individuals to develop the phenotype of females.
Dosage Compensation
balances the dose of X chromosome gene expression in females and males
Imprinting
A phenomenon in which expression of a gene depends on whether it is inherited from the mother or the father
Epigenetics
Inheritance of temporary chemical Modifications of DNA affecting gene expression patterns
X inactivation center (Xic)
is located on the proximal end of the p arm in humans, and its genetic expression occurs only on the X chromosome that is inactivated.
X-inactive specific transcript (XIST)
a gene that is critical to inactivation.
sex-influenced traits
an autosomal trait that is influenced by the presence of male or female sex hormones
sex-limited traits
Inherited by both males and females but expressed in only one sex
pattern baldness
Acts like an autosomal dominant trait in males and an autosomal recessive trait in females.
Due to differences in testosterone levels.
somatic mutation
occur in cells of the body that do not form gametes
Are not transmitted to future generations
germ-line mutation
Occur in cells that produce gametes
Transmitted to future generations- inherited
Mutation Rate
The number of events that produce mutated alleles per locus per generation
Size of the gene
Larger genes have higher mutation rates
nucleotide sequence
Presence of nucleotide repeats are associated with higher mutation rates
Spontaneous chemical changes
C/G base pairs are more likely to mutate than A/T pairs
What environmental agents cause mutations
Radiation and chemicals
ionizing radiation
radiation that produces ions during interaction with other matter, including molecules in cells
background radiation
radiation in the environment that contributes to radiation exposure
Rem
The unit of radiation exposure used to measure radiation damage in humans.
It is the amount of ionizing radiation that has the same effect as a standard amount of X-rays.
Millirem
A rem is equal to 1,000 millirems
nucleotide substitutions
Involve replacing one or more nucleotides in a DNA molecule with other nucleotides
Frameshift mutations
a number of bases (other than multiples of three) are added to or removed from DNA, causing a shift in the codon reading frame
allelic expansion
increase in gene size caused by an increase in the number of trinucleotide repeat sequences.
epigenetic trait
phenotype that is produced by epigenetic changes to DNA
Epigenome
Epigenetic state of a cell
Can change multiple times over the lifespan of the cell, depending on the environment
proliferation
Uncontrolled cell division
metastasis
metastasis
The ability of these cells to spread to other sites in the body
invasive and spreads
Benign
Non -invasive
mutator phenotype
high level of genomic instability in cancer cells
genomic instability
an increased tendency of the genome to acquire mutations when various processes involved in maintaining and replicating the genome are dysfunctional
Sporadic cancer
Cancer caused by accumulation of a number of mutations in somatic cells
Mutation occurs in a single somatic cell
Inherited cancer syndromes
Inherited mutant genes cause a predisposition to cancer
* Mutations are carried in all cells in a heterozygous state
* The normal allele is lost in the cancer cell (loss of
heterozygosity)
G1/ S
checkpoints monitor cell size and determine whether DNA has been damaged
G2/ M
Physiological conditions are checked (once G1/S are passed) prior to mitosis
M
the formation of the spindle-fiber system and the attachment of spindle fibers to the kinetochores associated with the centromeres are monitored
Proto- oncogenes
are genes whose products promote cell growth and division.
tumor suppressor genes
Regulate cell-cycle checkpoints and initiate process of apoptosis
tumor suppressor genes
Regulate cell-cycle checkpoints and initiate process of apoptosis
Oncogenes
genes that induce or continue uncontrolled cell proliferation
familial retinoblastoma
familial retinoblastoma
Individuals inherit one mutant copy of RB1 gene
* 85% to 95% chance of developing the disease
familial retinoblastoma
familial retinoblastoma
Individuals inherit one mutant copy of RB1 gene
* 85% to 95% chance of developing the disease
Sporadic retinoblastoma
Mutations of both copies of RB1 gene occur in a
single cell
* Occurs with a frequency of approximately 1 in 15,000
Microsatellites
DNA sequences, 2 to 9 nucleotides long, that are repeated thousands of times and located on many chromosomes
Epidemiology
The study of factors that control the presence, absence, or frequency of a disease
Cloning
The production of identical copies of molecules, cells, or organisms from a single ancestor
embryo splitting
After in vitro fertilization, early embryonic cells are divided and grown into clones
Nuclear transfer (cell fusion)
Enucleated eggs are fused with embryonic or adult cells and grown into clones
Dolly the sheep
Recombinant DNA technology
A series of techniques in which DNA fragments are linked to self-replicating vectors to create recombinant DNA molecules, which are replicated in a host cell.
Probe
a labeled nucleic acid used to identify a complementary region in a clone or genome by hybridization
Southern Blot
A method for transferring DNA fragments from a gel to a membrane filter, developed for use in hybridization experiments
Biotechnology
is the use of recombinant DNA and molecular biology to produce commodities or services
enzyme replacement therapy
treats the disease by replacing the damaged or nonfunctional enzyme sourced from alternative sources
Stem cells
unspecialized cells that are able to renew themselves for long periods of time by cell division
Embryonic stem (ES) cells
form during the blastocyst stage of development.
ES cells are
pluripotent- they can become any cell type except trophoblast cells
Adult Stem (AS) cells
are derived from adult tissues and umbilical cord blood
Mainly divides and replaces worn out or damaged cells
AS cells are
Multipotent they can become a limited set of cell types
Artificial selection
Selection by humans for breeding of useful traits from the natural variation among different organisms
what are the 3 main goals of transgenic animals research
produce an animal with symptoms that mirror those in humans
use the model to study the early stages of disease development and progression
test drugs to treat symptoms or cure the disease
DNA Fingerprints
patterns of bands made up of specific fragments from an individuals DNA
Microsatellites
short repetitive sequences found throughout genome
