Block 1 - Genetics Flashcards
What is the term for each definition?
The carrier of genetic information.
An ordinary chromosome; one that does not determine sex of the individual.
A chromosome that is causally associated with the sex of an individual:
–X chromosome (female)
–Y chromosome (male)
chromosome
autosome
sex chromosome
Alternative forms of a gene that code for the same trait and are at the same location on homologous chromosomes are called _______.
alleles
In what process does this occur?
“The homologous chromosomes are segregated from each other, then two haploid cells are formed, each containing one of the segregates.”
Meiosis I
Chromatids of homologous chromosomes form chiasmata wherein matching regions break and then reconnect to the other chromosome.
Crossing over
What is the failure of chromosome pairs to separate properly during cell division?
This particular abnormality is responsible for what type of chromosomal abnormality?
nondisjunction
monosomy
What phase(s) are briefly described below?
the chromatin fibers change into chromosomes.
microtubules align the centromeres of the chromatid pairs at the metaphase plate.
the chromatid pairs split at the centromere and move to opposite poles of the cell; the chromatids are now called chromosomes.
two identical nuclei are formed around the identical sets of chromosomes now in their chromatin form.
prophase
metaphase
anaphase
telophase
What is the term for somatic cell division?
Mitosis
Define:
“Chromosomes of the same kind”.
What are the attributes of these “alike” chromosomes?
Humans are______, meaning there are two of every general type of chromosome in ordinary body cells—i.e. a homologous pair
homologous chromosomes
attributes:
–Have the same linear sequence of genes
–Look alike
–Pair during meiosis
diploid
Where does transcription of DNA occur?
in the nucleus
Described the process of “forward typing”.
Bloods are mixed with different antisera of known type. Agglutination occurs when the red cell antigens (which are unknown) correspond to the antibodies in the antisera (which are known). This is called forward typing.
When does “crossing over” occur?
prophase I
What disease is the most common problem with Rh incompatibility, and is associated with an Rh- mother, and an Rh+ fetus?
Blood contact is common during delivery. The mother will then produce anti-Rh antibodies, which are mostly ___ (the only class of antibody to cross the placenta), which can affect any subsequent Rh+ fetus.
Hemolytic diesease of the newborn
IgG
How many antigens and antibodies are generally responsible for the ABO blood types?
What blood types are codominant?
2 antigens, 2 antibodies
A and B
This cell cycle is a sequence of events in which a body cell duplicates its contents and divides in two?
These cells contain how many pairs of chromosomes?
These pairs are referred to as what?
mitosis
23 pairs (46 total)
homologous pairs (homologs)
What is the term for the physical expression of a gene?
What term refers to the genetic makeup of an individual?
phenotype
genotype
What system is the most complex of all RBC human blood groups because it produces over thirty antigens?
The Rh-hr (Rhesus) blood group system
Meiosis I begins with a diploid cell and ends with two cells having the haploid number of chromosomes; in Meiosis II, each of the ____ haploid cells divides, and the net result is ____ haploid gametes that are genetically different from the original diploid starting cell.
two
four
How many pairs of autosomes are in a human karyotype?
22 pairs
The number of chromosomes in egg and sperm of an organism. Represented by the letter “n”.
The number of chromosomes in ordinary body cells of an organism. Represented by twice the gametic number, or 2n.
gametic number
somatic number
Sex linked genes are genes located on the sex chromosomes (in mammals, the X and Y chromosomes). In general usage, sex linkage is synonymous with which chromosome?
X chromosome
In X-Linked inheritance,
Females transmit an X chromosome both to sons and daughters.
Males transmit X chromosomes only to their daughters
Characteristic feature of X linked inheritance is absence of __________ to __________ inheritance.
(this means absence of father to son inheritance)
All daughters of an affected male are ________ _______.
heterogamete to heterogamete
obligate carriers
True or False: A person with Pp (a heterozygote) has a different genotype from a person with PP (a homozygote), but both have the same phenotype.
True
What are some phenotypical aspects of:
Down’s Syndrome
Klinefelter’s Syndrome
Turner’s Syndrome
DS: large tongue, flat face, slanted eyes, single bilateral crease across palm, mental retardation is typicaly however some are not
KS: breast development, small testest (infertility), low serum testosterone level but high serum follicle-stimulating hormone and lutenizing hormone levels, some degree of landuagelearning impariment, intelligence may be lower than “normal”, in severe cases-increased risks shared with females: germ cell tumors, male breast cancer, osteoporosis
TS: Delayed early growth. Short stature, Hands and feet swollen or puffy at birth, Broad chest with widely-spaced nipples (even as a toddler), Produce little estrogen, therefore usually sterile and do not go through puberty, Extra skin on neck (webbed neck), Cubitus valgus (milkmaid arms), Difficulties with math and spatial concepts, Hearing and kidney problems, and heart defects are common
What is the term that describes when an individual is born with chromosomes added or missing?
What is the term for having only one chromosome?
What is the term for having three chromosomes?
aneuploidy
monosomy
trisomy
