Final Flashcards
karyotype
the chromosomal composition of an individual
pedigree
a chart constructed to show an inheritance pattern within a family through multiple generations
aneuploidy
any chromosomal aberration in which there are either extra or missing copies of certain chromosomes
trisomy
a type of aneuploidy in which an individual has two copies of each chromosome except for one, which has three copies; designated 2n+1
monosomy
a type of aneuploidy in which an individual lacks one member of a pair of chromosomes; designated 2n-1
translocation
Chromosome abnormality in which part of one chromosome has become attached to another
deletion
the loss of one or more base pairs from DNA, which can result in a frameshift mutation
fragile sites
a weak point at a specific location on a chromosome where part of a chromatid appears attached to the rest of the chromosome by a thin thread of DNA
polyploidy
the condition of having more than two sets of chromosomes per nucleus; common in plants, rare in animals
genome-wide association scans
compare the genomes of individuals with a particular disease to healthy individuals without that disease
disomy
the normal condition in which both members of a chromosome pair are present in a diploid cell or organism
nondisjunction
abnormal separation of sister chromatids or of homologous chromosomes caused by their failure to disjoin (move apart) properly during mitosis or meiosis
duplication
an abnormality in which a set of chromosomes contains more than one copy of a particular chromosomal segment; the translocation form of Down syndrome is an example
inversion
a chromosome abnormality in which the breakage and rejoining of chromosome parts results in a chromosome segment that is oriented in the opposite (reverse) direction
amniocentesis
sampling of amniotic fluid surrounding a fetus to obtain information about its development and genetic makeup
chorionic villus sampling (CVS)
study of extra embrionic celss that are genetically identical to the cells of an embryo, making it possible to assess its genetic makeup
pre-implantation genetic diagnosis (PGD)
a physician screens the embryos for one or more genetic diseases before placing a healthy embryo into the woman’s uterus during in vitro fertilization
human genome
the totality of genetic information in human cells; includes the DNA content of both the nucleus and mitochondria
What diseases are examples of trisomy 21?
Down syndrome and klinefelter syndrome
bioinformatics
storage, retrieval, and comparison of DNA
pharmacogenetics
drugs customized to an individual
proteomics
study of proteins encoded by human genome
genomic/parental imprinting
the expression of a gene in a given tissue or developmental stage is based on whether the gene was inherited from the male or female parent
What disease is an example of trisomy 13? Trisomy 18?
Trisomy 13: Patau Syndrome, trisomy 18: Edward syndrome
What two rare genetic disorders can occur due to parental imprinting? Which is associated with which parent?
Prader-Willi Syndrome (PWS) is a disorder where individuals become compulsive overeaters and obese, they are also short in stature and mildly to moderately retarded, PWS occurs when the offspring inherits the deletion from the father; In Angelman Syndrome, affected individuals are hyperactive, mentally retarded, and unable to speak, and they suffer from seizures, when the offspring inherits the deletion of several loci from the mother, AS occurs.
What is autosomal recessive disorder? What diseases can result from it?
autosomal recessive disorder means that two copies of the abnormal gene have to be present in order for the disease or trait to develop; diseases that can result from it are PKU and sickle cell anemia
What is autosomal dominant disorder? What diseases can result from it?
autosomal dominant disorder means that you only need to get the abnormal gene from one of the parents in order for you to inherit the disease, one of the parents may often have the disease; a disease that can result from this is Huntington’s disease
What is X-linked recessive disorder? What diseases can result from it?
a x-linked recessive disorder is a genetic disease caused by a gene mutation on the x chromosome (one of the chromosomes that determines the person’s gender, it’s caused when a male inherits the mutated gene from his father or (more rarely) when a woman inherits it from both parents; a disease resulting from this is hemophilia
cell determination
the developmental process by which one or more cells become progressively committed to a particular fate. Determination is a series of molecular events usually leading to differentiation
cell differentiation
development toward a more mature state; a process changing a young, relatively unspecialized cell to a more specialized cell
morphogenesis
the development of the form and structures of an organism and its parts; proceeds by a series of steps known as pattern formation
differentiated cells
a specialized cell; carries out unique activities, expresses a specific set of proteins, and usually has a recognizable appearance
zygote
the 2n cell that results from the union of n gametes in sexual reproduction. Species that are not polyploid have haploid gametes and diploid zygotes.
nuclear equivalence
the concept that the nuclei of all dfiferentiated cells of an adult organism are genetically identical to one another and to the nucleus of the zygoted from which they were derived
totipotency
a term describing a cell or nucleus that contains the complete set of genetic instructions required to direct the normal development of an entire organism
differential gene expression
the expression of different subsets of genes at different times and in different cells during development
induced pluripotent stem (iPS) cells
a term describing a stem cell that can divide to give rise to many, but not all, types of cells in an organism
RNA interference (RNAi)
phenomenon in which certan small molecules interfere with the expression of genes or their RNA transcripts; RNA interference involves small interfering RNAs, microRNAs, and a few other kinds of short RNA molecules
segmentation genes
in Drosophila, genes transcribed in the embryo that are responsible for generating a repeating pattern of body segments within the embryo and adult fly
gap genes
map out the basic subdivisions along the anterior-posterior axis, mutations cause “gaps” in segmentation
pair-rule genes
divide the embryo into strips, each about two segments wide, and influence activity of segment polarity genes, mutations result in embryos with half the normal segment number
segment polarity genes
define all segments of body, and divide each segment into anterior and posterior halves, mutations produce embryos with the normal segment number, but with part of each segment replaced by a mirror image repitition of some sort
morphogen
any chemical agent thought to govern the processes of cell differentiation and pattern formation that lead to morphogenesis
homeotic genes
a gene that controls the formation of specific structures during development. such genes were originally identified through insect mutants in which one body part is substitued for another
homeobox
a short (180 nucleotide) sequence that characterizes many homeotic genes as well as some other genes that play a role in development
homeodomain
a functional region of certain transcription factors; consists of approximately 60 amino acids specified by a homeobox DNA sequence and includes a recognition alpha helix, which binds to specific DNA sequences and affects their transcription
hox genes
clusters of homeobox-containing genes that specify the anterior-posterior axis of various animals during development
mosaic development
a rigid developmental pattern in which the fates of cells become restricted early in development
induction
the process by which the differentiation of a cell or group of cells is influenced by interactions with neighboring cells
apoptosis
programmed cell death; apoptosis is a normal part of an organism’s development and maintenance
chimera
an organism consisting of two or more kinds of genetically dissimilar cells
ABC model
explains how three classes of homeotic genes control the development of the four floral organs; this modely may help explain the thousands of different forms of flowers that have evolved
oncogenes, proto-oncogenes
oncogene: an abnormally functioning gene implicated in causing cancer; proto-oncogene: a gene that normally promotes cell division in response to the presence of certain growth factors; when mutated, it may become an oncogene, possibly leading to the formation of a cancer cell
tumor suppressor gene
a gene (also known as an anti-oncogene) whose normal role is to block cell division in response to certain growth-inhibiting factors; when mutated, may contribute to the formation of a cancer cell
rmaternal effect genes
genes of the mother that are transcribed during oogenesis and subsequently affect the development of the embryo
