Test Four Bio 1000

Question Answer
Define genome the sum total of all DNA in an organism
Define gene a length of DNA that has directions to make a product
Define allele variation on a gene
Define homozygous when the allele is the same (FF or ff)
Define hetrozygous when you have one of each gene (Ff)
Define dominant allele hides a recessive allele
Define phenotype what you physically see
Define genotype what the genes tell you
Define autosomes all other chromosomes (1-22)
Define sex chromosomes X and Y
Define mutation a heritable change in the DNA that can be passed on
Who was the first to study genetics and heredity and when? Gregor Mendel in the 1860s
What is heredity? passing your characteristics from generation to generation
What are characters? heritable features
What are traits? variations of a character
What is true-breeding? crossing two homozygous organisms
When you cross two true-breeding parents, what are the offspring? always heterozygous
What is a monohybrid cross? a cross between two individuals, researching only one character
What is the Law of Segregation? gametes divide the chromosome number in half
What is the Law of Independent Assortment? the inheritance of one gene has no effect on the inheritance of another
True/False there are both recessive and dominant disorders true
What are recessive disorders? those with recessive genes.. needing one from each parent to show in the phenotype
What does inbreeding do? increases the probability of inheritance
What is an example of a recessive disorder? cystic fibrosis
What are dominant disorders? like other dominant traits, only need one copy of a gene to express itself
What are two examples of dominant disorders? achondroplasia and huntington's disease
What is achondroplasia? the most common of over 200 forms of dwarfism
What is Huntington's disease? degenerative nervous system disorder
Define pleiotropy one gene controls the expression of many characteristics
Define incomplete dominance the heterozygous state does not display the homozygous dominant trait, but rather on an intermediate state
What does the law of segregation depend on? the separation of homologous chromosomes
What does the law of independent assortment depend on? alternative orientations of chromosomes
Define linked genes genes that are closely related on a chromosome
What are 3 examples of recessive and sex linked disorders hemophilia, red-green color blindness, duchenne muscular dystrophy
Define hemophilia lacking certain proteins for blood clotting
Define duchenne muscular dystrophy progressive weakening of muscles and loss of coordination
Which gender is most likely to be affected by sex-linked disorders and why? males because they only need one copy while women need two
How do you track the female line? by looking at the mitochondrial DNA
What theory did Charles Darwin develop? the "theory of evolution by natural selection"
What does descent with modification mean? each generation is a little different
Define adaptations a change that will help you survive
What is artificial selection? man controlling evolution
What 2 things did Darwin observe about organisms? they show individual variation and produce more offspring than the environment can support
What 2 things did Darwin infer about organisms? organisms with traits that increase their chance of living and reproducing will leave more offspring and the unequal reproduction will lead to accumulation of favorable traits
What three points clarify Darwin's proposal of natural selection? 1) individuals do not evolve: populations do 2) only heritable traits are affected by natural selection; not acquired traits 3) evolution is not goal directed. favorable traits vary as environments change
Define fossil record the sequence in which fossils are found in the strata
What is the strata? the layers of the earth
Define speciation the formation of a new species
Define homologous structures structures that are the same because they have common ancestors – body parts which have common structure due to a common ancestry
Define analogous structures structures which have a common function due to environmental pressures instead of together
Define comparative anatomy examining the morphological structures of two or more species
Define comparative embryology examination of embryonic development from one population to a different population
What does molecular biology compare? the proteins in an organism
What do examples of evolutionary adaptations show about natural selection? natural selection is an editing process and not a creative mechanism – does not start new adaptations
What does natural selection rely on? time and place – characteristics that fit the current, local environment enable those organisms to survive
What is the ultimate source of change? mutation
What is microevolution? a change in the relative allele frequency in a gene pool over time
What is the gene pool? the total collection of genes in the population at any given time
How can mutations be passed to offspring? only in gametes
What are the 3 types of genetic drift? bottleneck effect, founder effect, and gene flow
Explain the bottleneck effect something happens causing some things to die out
Explain the founder effect a group gets taken to a whole new environment and have to learn to adapt
Explain gene flow individual organisms moving from one population to another
What is relative fitness? the contribution an individual makes to the gene pool of the next generation relative to the contribution of other individuals
The fittest individuals are those that… (2) produce that largest number of viable, fertile offspring and pass on the most genes to the next generation
What is biological "fitness"? also called something else the ability to survive to get your genes into the next generation
What can natural selection affect? the distribution of phenotypes
What are the 3 ways of distributing phenotypes? stabilizing selection, directional selection, and disruptive selection
Define stabilizing selection increases intermediate phenotypes by acting against extreme phenotypes
Define directional selection acts against individuals at one of the phenotypic extremes
Define disruptive selection increases both extremes of the phenotypic range by acting against the middle phenotype
What is dimorphism? 2 different phenotypes (male and female)
What are the two type of sexual dimorphism? intersexual and intersexual
Define intrasexual selection involves competition – males fighting for mates or territory – within the sex
Define intersexual selection involves mate choice – females choose their mates
What is the average generational time of bacteria? 30 minutes
Define taxonomy the branch of biology that names and classifies organisms
What is used in taxonomy and who developed it and when? binomial nomenclature introduced by Linnaeus in the 18th century
How do we define species? by phenotype
What are the 4 types of species concepts used to define species? biological species concept, morphological, ecological, and phylogenetic species concept
Describe the biological species concept a population or group of populations whose members have the potential to interbreed and produce viable, fertile offspring
Describe the morphological species concept based on observable and measurable phenotypic traits
Describe the ecological species concept classifies in terms of ecological niche, and unique adaptations – where do they fit
Describe the phylogenetic species concept set of organisms with a unique genetic history, based on DNA sequences – looking at generations
What is the most commonly used concept and why the biological species concept because it works for us and it works for the majority of organisms so we use it
What is a reproductive barrier? biological feature of the organism itself that prevents successful breeding with another species
What are the two types of reproductive barriers? prezygotic and postzygotic
Define prezygotic barriers that stop you from getting a fertilized egg
Define postzygotic get an egg but something stops it from reproducing
How are species distinct because of reproductive barriers? they are distinct when they don't share the same gene pool
What are the types of prezygotic barriers? (5) habitat, temporal, behavioral, mechanical, and gametic isolation
Define habitat isolation different habitats
Define temporal isolation breeding at different times
Define behavioral isolation different courtship rituals (mating rituals)
Define mechanical isolation incomplete reproductive parts
Define gametic isolation incompatible gametes – they don't fit
What are the types of postzygotic barriers? (3) reduced hybrid viability(hybrid inviability), reduced hybrid fertility(hybrid infertility), and hybrid breakdown
Define reduced hybrid viability (hybrid inviability) short-lived hybrids – won't live long
Define reduced hybrid fertility (hybrid infertility) sterile hybrids – can't reproduce (ex mule)
Define hybrid breakdown fertile hybrids with sterile offspring
What is allopatric speciation? requires a geographical separation
What is sympatric speciation? a new species within the same geographic area
What types of organisms might sympatric speciation be more important for? plants
Define polyploids more sets of chromosomes than the parents
What is adaptive radiation you are adapting as you radiate from the original population
One of three things can happen when two populations interbreed, what are they? reinforcement, fusion, stability
What are the two models for the tempo of speciation? punctuated equilibria and gradualism
What is tempo of speciation? the speed is baed not the environment
What is punctuated equilibria? time with no change then a dramatic change then time with no change again
What is gradualism? tiny slow changes happening

Leave a Reply

Your email address will not be published. Required fields are marked *