Exam 2 Flashcards
What are multifactorial traits?
traits that result from the interaction of one or more environmental factors and two or more genes
What are polygenic traits?
Traits that are controlled by two or more genes
What are complex traits?
Traits controlled by multiple genes, the interaction of genes with each other, and with environmental factors where the contribution of genes and environment are undefined
What is norm of reaction?
It is a curve that relates, for a given phenotype, the contribution of environmental variation to observed phenotypical variation
What is the normal curve of variation?
the bell curve
What are 1st degree relatives?
Parents, siblings, and children
What are 2nd degree relatives?
Grandparents, nephews, aunts, uncles, nieces
What are third degree relatives?
First cousins, great-grandparents and great-grandchildren
What is a quantitive trait?
the product of two or more genes and their environment
What is quantitive trait loci?
stretches of DNA containing or linked to the genes that underlie a quantitive trait
What heritability?
An expression of how much of the observed variation in a phenotype is due to differences in genotype
What is variance?
genetic diversity in a population as a result of gene combinations
What concordance?
Agreement between traits exhibited by both twins
What is hypertension?
high blood pressure
What is atherosclerosis?
hardening of the arteries
What is karyotype?
A complete set of chromosomes from a cell that has been photographed during cell division and arranged in a standard sequence
What is a centromere?
A region of a chromosome to which spindle fibers attach during cell division. The location of a centromere gives a chromosome its characteristic shape
What is a biopsy?
The medical removal of a tissue to determine the presence of a disease
What is a polyploid?
An organism with one or more extra sets of chromosomes
What is a euploid?
Having a balanced set of any number of chromosomes
What is a aneuploid?
Having a chromosome number not a multiple of a haploid number
What is cytogenetics?
The branch of genetics that studies the organization and arrangement of genes and chromosomes by using the techniques of microscopy
What is triploid?
Having three of every chromosome in a set
What is a tetraploid?
Having four of every chromosome in a set
What is monosomy?
A condition in which one member of a chromosomal pair is missing; having one less than the diploid number (2n-1)
What is trisomy?
A condition in which one chromosome is present in three copies, whereas all others are diploid; having one more than the diploid number (2n+1)
What is deletion?
A mutation in which part of a chromosome or sequence of a DNA is missing
What is duplication?
Any duplication of a region of DNA that contains a gene
What is inversion?
A chromosomal rearrangement in which of segment of a chromosome undergoes breakage and rearrangement within itself
What is translocation?
A chromosomal abnormality caused by rearrangement of parts between nonhomologous chromosomes
What is an acentric chromosome?
A chromosome lacking a centromere
What is a dicentric chromosome?
An aberrant chromosome with two 2 centromeres
What is mosaic?
The presence of two different genotypes in an individual which developed from a single fertilized egg
What is a double-blind study?
An experimental procedure in which neither the subjects of the experiment nor the persons administering the experiment know the critical aspects of the experiment
What is dispermy?
The entrance of two spermazoa in one egg
What is vas deferens?
A duct connected to the epididymis, which sperm travels through
What is oviduct?
A duct with fingerlike projections partially surrounding the ovary and connecting to the uterus. Also called fallopian tubes
What is the uterus?
A hallow, pear shaped muscular organ where an early embryo will implant and develop through pregnancy
What is the placenta?
An organ that connects the developing fetus to the uterine wall which allows nutrient intake, waste elimination
What are gonads?
Organs where gametes are produced
What are testes?
Male gonads that produce spermatozoa and sex hormones
What is an ovary?
Female gonads that produce oocytes and female sex hormones
What is fertilization?
The fusion of two gametes to produce a zygote
What is an androgen?
male sex hormone
What is barr body?
A densely staining mass in the somatic nuclei of mammalian females; an inactivated X chromosome
What is a hermaphrodite?
An organism that has both male and female organs
What is a pseudohermaphrodite?
One that possesses the internal reproductive organs of one sex while exhibiting physical characteristics of the opposite sex
What is testosterone?
A steroid hormone produced by the testes; the male sex hormone
What is estrogen?
the female sex hormone
What is progesterone?
A female hormone produced by the ovaries during during release of a mature egg from an ovary
What is ambiguous sex?
One who is independent of sexual orientation
How are continuous variation and discontinuous variation different?
Discontinuous variation is genetic variations with extremes (pea plants) Continuous is a wide overlapping pattern (human traits)
As the number of loci affecting a trait increases, what happens to the phenotypic distribution?
the phenotypical distribution increases
What is the threshold effect?
Diabetes, and other traits like it, are thought to appear only when enough contributing genetic and environmental factors are present. Below that threshold value, the trait is not expressed.
How does the threshold effect relate to multifactorial inheritance?
In multifactorial disorders the risk of recurrence depends on consanguinity, previous affected child, and severity of defect
What is the difference between a heritable trait and a familial trait?
An heritable trait is one you can pass down. For example liking rap because you grew up with is a non heritable trait
What is the difference and the genetic consequences between dizygotic twins and monozygotic twins?
Monozygotic is from one fertilization involving one egg and one sperm, they are genetically identical. Dizygotic are derived from two separate and nearly simultaneous fertilizations. Share on average 50% of genes.
What is regression to the mean and why it happens?
the samples appear to regress towards the mean.
How does IQ relate to intelligence?
IQ is an intelligent test
