BIOL 323 Study Guide, Exam One
BIOL 323 Study Guide, Exam One BIOL 323
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This 6 page Study Guide was uploaded by Emma Marquez-Shaw on Monday September 19, 2016. The Study Guide belongs to BIOL 323 at California State University Chico taught by Rebecca Brunelli in Fall 2016. Since its upload, it has received 65 views.
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Date Created: 09/19/16
BIO 323 Study Guide: Exam One Science: Basic Concepts o Hypothesis- Educated guess o Prediction- o Independent Variable- The one thing that you change o Dependent Variable- The one thing you measure o Controlled Variable- The rest, stays the same o Control Group- The normal/usual thing or group o Experimental Group- The group that receives something Proof: In science, there is no “real” scientific proof (nothing is 100% proven) Theory: So much evidence for it, we know it’s the case Significance: Had a hypothesis and It was supported Double -Blind: Both the researcher and the subjects don’t know their treatments Single-Blind: Only the subjects don’t know their treatments Open-Label: Both the researcher and subjects know their treatments Replication: Don’t do one study and say that it’s complete, keep doing it Designing a Scientific Experiment: o Study Question o How many subjects will you need? o Time frame? o How will you conduct the experiment? o Dependent Variable? o Independent Variable? o Controlled Variable? o Control and Experimental Groups? o Double-blind, Single-blind, or Open-label? o How will you collect your data? o Conclusion? Evolution: Genetic variation: o Happens within a species o Evolution needs it Genotype: Genetic code in cells Phenotype: Things you can observe, physically and behaviorally Adaptations: o Feature common in a population because it provides some improved functions o Produced by Natural Selection o Adaption Examples: Mimicry of Leaves Allelopathy Evolution: The process in which populations of organisms diversify from their ancestors Evidence for Evolution: o Paleontology Fossils Transitional Fossils o Biogeography Study of the past and present geographical distribution of organic Similar species can be traced to an origin o Comparative Anatomy Shows us how organisms adapt ancestral features to new uses Homologous- Similar anatomy, different ancestors Analogous- Similar functionality, different anatomy o Vestigial Structures Things that were an adaptation for our ancestor, but now are not used anymore Examples: appendix, goosebumps, tail bone, palmer reflex o Developmental Biology/Embryology Study the embryos of different species and see how related species go through development o Genetics/Genomics, Molecular Biology and Biochemistry Look at genetics of modern organisms Evolutionary Mechanisms o Mutations: A change in the DNA A source of genetic variation Why does it happen? DNA copy mistake External influences Mutations are RANDOM (natural selection IS NOT) Somatic Mutations: Occur in non-reproductive cells Not passed to offspring Does not affect evolution Germ-line Mutations: Occur in reproductive cells Can pass to offspring Does affect offspring Single Germ-line Mutations Cause: Cause no, small, or large changes to the phenotype o Natural Selection Charles Darwin: Credited with the idea of Natural selection Genetic Variation Individuals within a species vary Genetic differences are heritable Descent with modification- a type of mutation Common Descent: All life on Earth has descended from a common ancestor Artificial Selection: Imposed by humans Natural Selection: Naturally occurring “Survival of the fittest” Not an accurate term Gives the idea that only the fittest survive The strongest and fastest aren’t necessarily the ones to survive To be fit in an evolutionary sense, it’s important to succeed in their environment Natural Selection IS NOT random (Mutations ARE random) Speciation: When new species arise by natural selection Isolation: Geographical o Rivers, mountains, distances, etc. o Continental drift Ecological o Geographic ranges of two species overlap, but occupy different habitats Temporal o Breeding at different times o Seasonal or daily Mechanical o Physical differences prevent mating o Failure of gametes (sperm cells/eggs) to fuse Behavioral o Differences in courtship behavior, songs, nesting, etc. Types of Speciation: Anagenesis- One species evolves into another species Cladogenesis- Either stays the same or evolves into a new species o Extreme Cladogenesis: Adaptive Radiation o Migration/Gene Flow Another source of genetic variation Any movement of genes from one population to another o Genetic Drift By chance, some individuals may leave more descendants It happens to all populations Entirely random Cells, Chromosomes, DNA, and Genes Why is sex important? o Sexual reproduction gives us new combination of genes o Can also break up beneficial combinations of genes DNA chromosomes are found in the nucleus of the cell Humans have 23 kinds of chromosomes o Two of each kind of chromosome o 46 total chromosomes/23 pairs total o 46 chromosomes in every cell (except red blood cells and sex cells) Every gene we have lives in every cell in our body (except red blood cells) Every species has a different number of chromosomes A greater/lesser number doesn’t mean more/less complex Sex Cells: o Gamete (egg): 23 chromosomes o Gamete (sperm): 23 chromosomes o First cell: zygote (46 chromosomes/23 pairs) Haploid: total number of pairs (ex. Humans have 23) Diploid: total number of chromosomes (ex. Humans have 46) Karyotype: inventory of chromosomes lined up in order of size Homologous Pairs: o Two chromosomes that match o Humans have 23 homologous pairs o Match in genes and size Locus: address on the chromosome where the gene lives Allele: different versions of a gene Capital letter=always dominant Lowercase letter=always recessive Homozygous Dominant: two dominant alleles Homozygous Recessive: two recessive alleles Heterozygous: one dominant and one recessive allele Incomplete Dominance: heterozygous phenotype is intermediary blend Co-dominance: doesn’t get the blend of two phenotypes, but instead get a pattern of both phenotypes Multiple alleles o Some genes have more than two alleles o Each individual can only have two alleles Polygenic Traits: multiple genes for one trait Mitosis and Meiosis Mitosis: o Happens in all the diploid cells in the body o Two new daughter cells, each containing an identical copy of DNA o Stages (IPMAT) Interphase DNA not condensed yet DNA starts to replicate Prophase DNA condenses Nucleus disintegrates Sister chromatids become visible Sister chromatids joined by centromeres Spindles form Metaphase Chromosomes line up at equator Spindles attach to centromeres Anaphase Spindles pull chromatids apart to opposite ends Telephase DNA “uncondenses”, nucleus reforsm Meiosis: o Happens in reproductive cells only o Haploid gametes are created o Stages (IPMATPMAT) Interphase Prophase I Nucleus Disintegrates DNA condenses Sister chromatids become visible Spindles start to form Homologous pairs Recombination occurs Metaphase I Homologous pairs line up at equator Anaphase I Spindles pull each one of homologous pairs apart Telephase I Nuclear envelope reforms Cells now in two haploid cells Still too much DNA Prophase II DNA condenses again Spindles start to form Nuclear envelope disintegrates Metaphase II Individual chromosomes line up on equator Not homologous pairs (key difference from Metaphase I) Anaphase II Sister chromatids are pulled apart Telophase II Nucleus reforms Cytokinesis splits the cells Four haploid cells Sister Chromatids: Pair of chromosomes Recombination: gives us variation in our offspring
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