Bio Exam Stuff (PDF)

1. Know key terms like fossils, paleontology, archaeopteryx, Homologous features, Analogous features, Vestigial features, Fossil- fossils are the preserved remains of plants and animals whose bodies were buried in sediments, such as sand and mud, under ancient seas, lakes and rivers. Paleontology -...

1. Know key terms like fossils, paleontology, archaeopteryx, Homologous features, Analogous features, Vestigial features, Fossil- fossils are the preserved remains of plants and animals whose bodies were buried in sediments, such as sand and mud, under ancient seas, lakes and rivers. Paleontology - scientific study of life of the geologic past that involves the analysis of plant and animal fossils, including those of microscopic size, preserved in rocks. the branch of science concerned with fossil animals and plants. Archaeopteryx- the oldest known fossil bird, of the late Jurassic period. It had feathers, wings, and hollow bones like a bird, but teeth, a bony tail, and legs like a small coelurosaur dinosaur. Homologous structures - structures in different organisms that have similar anatomy and a recent shared ancestry but different functions Analogous structures - refers to the parts that have similar functions but different anatomical structures and no recent shared ancestry. (wing bat, birds, butterfly) Vestigial structures - anatomical parts that appear to have no functions. Ex- thumbs on dog paws, hip bone in whales, bats having eyes 2. Know early ideas about evolution. ​ Evidence for evolution - Molecular similarities ○​ DNA sequence - humans and chimpanzees share roughly about 98 to 99% of DNA sequence ○​ Pseudogenes - non functional sequence of DNA that have lost their ability to code for proteins due to mutation, similarities seen between species ○​ Similar amino acid sequence between species ○​ These similarities are evidence of evolutionary relationships and that species evolved from a common ancestor gradually over a long period of time ​ Evidence for evolution - Anatomical similarities ○​ Homologous structures - structures in different organisms that have similar anatomy and a recent shared ancestry but different functions ○​ Analogous structures - refers to the parts that have similar functions but different anatomical structures and no recent shared ancestry. (wing bat, birds, butterfly) ○​ Vestigial structures - anatomical parts that appear to have no functions. Ex- thumbs on dog paws, hip bone in whales, bats having eyes ​ Evidence for evolution - Development similarities ○​ In the embryonic stage many organisms have anatomical features that are similar to other organisms but these disappear before birth ​ Evidence for evolution - Fossil records  ​ These provide a timeline of evidence of evolution, showing how species have changed over time and adapted to their environments, including through transitional forms. They also have allowed scientists to study extinct species, support common ancestry through comparative anatomy, and highlight evolutionary adaptations, such as marine fossils found in dry regions. ​ Evidence for evolution - Biogeography ○​ Similar species are found around the world as the scientists believed all the continents were joined together (pangea), millions of years ago but they continents got split over time and the animals which were from same species lived in different parts got spread around the world 3. Know Darwin’s Theory of Natural Selection. ​ Darwin’s observations: ​ Species vary globally ○​ Distantly related species living in similar habitats around the world act similarly. Ex- rhea, ostrich ○​ Some areas have very unique organisms not present anywhere else. Ex- kangaroos in Australia ​ Species vary locally ○​ Related animals that lived in different habitats within a local environment had different features. Ex- galapagos islands ( very different climate - related animals had different features) ○​ Galapagos tortoise - tortoise varied locally. These islands have very different climates. Tortoise adapted differently to the climate they lived in. ​ Darwin’s theory ○​ All species of organisms living on the earth today are descended from an ancestral species ○​ Species evolve overtime ○​ The mechanism that causes the species to change is called natural selection ​ Natural selection - is not random. Organisms with traits better suited for the environment are more likely to survive and reproduce and pass on their traits to their offsprings. The fittest individuals have the reproductive advantage so the frequency of their allele in the gene pool is higher. Selective pressure in the environment change the relevant frequencies of phenotypes in a population: ​ Stabilizing selection - this happens when the average traits are best suited for survival and the extreme traits are less helpful. Ex - human birth weight, average sized babies have least problems ​ Directional selection - this happens when an extreme trait is best for survival causing the population to change in that direction over time ex antibiotic resistance  ​ Disruptive selection - this happens when extreme traits on both the ends are better for the survival than the average traits, leading to two very different groups in population 4. Know Modern Synthesis, Random Change in DNA, Genetic Drift, Gene Flow. ​ Genetic Drift: ​ Random change in the allele sequence due to chance. It has a much greater effect on small populations ​ Bottleneck effect: occurs when a population decreases generally due to a natural disaster. This decrease in population reduces variation in alleles, decreasing genetic diversity ​ Founders effect: a reduction in genetic diversity that occurs when a small group of individuals establishes a new population. ​ Gene flow: ​ The moment of alleles from one population to another ​ Happens when individuals from different populations mate and produce offsprings, sharing their genetic material ​ Can lead to increase in genetic diversity and sometimes introduce new traits to the population ​ Ex birds from one group migrate to another island and breed with a different group 5. Be able to explain patterns of selection. ○​ Natural selection - is not random. Organisms with traits better suited for the environment are more likely to survive and reproduce and pass on their traits to their offsprings. The fittest individuals have the reproductive advantage so the frequency of their allele in the gene pool is higher. Selective pressure in the environment change the relevant frequencies of phenotypes in a population: ○​ Stabilizing selection - this happens when the average traits are best suited for survival and the extreme traits are less helpful. Ex - human birth weight, average sized babies have least problems ○​ Directional selection - this happens when an extreme trait is best for survival causing the population to change in that direction over time ex antibiotic resistance ○​ Disruptive selection - this happens when extreme traits on both the ends are better for the survival than the average traits, leading to two very different groups in population ○​ Sexual selection- not random mates are often chosen based on their phenotypes. Other individuals in the species screen, or select their traits. ○​ Artificial selection - Not random humans have been modifying species for thousands of years. Can be fast - only a few generation traits that are  selected from can occur at a high frequency. Can have unintended consequences, usually in the form of genetic diseases. Ex all dogs come from the wolves. 6. Formation of a species. ​ Prezygotic barriers - a barrier that either impedes mating between species or prevent fertilization of eggs ○​ Behavioral isolation - difference in mating calls or mating rituals. Ex courtship rituals of elk, birds song ○​ Temporal isolation - mating occurs at different times of the year or day. Ex: orchids - times of the day, ○​ Habitat isolation - differences in using resources and living spaces within the same habitat. Ex: cichlids- feeding on different sources within the same habitat ○​ Mechanical Isolation- where species can attempt mating but fail because they are automatically incompatible. Ex- dogs - size incompatible, Damselflies - different shaped reproductive organs ○​ Gemate isolation - when the sperm and eggs of different species are incompatible preventing fertilization. Ex coal protein , flowers - pollen vs stigma, sea urchin - red vs purple ​ Postzygotic barriers - a barrier that prevents hybrid zygotes developing viable, fertile individuals ○​ Hybrid sterility - when the offspring of the cross between 2 individuals is infertile. Ex mule (horse and donkey) ○​ Hybrid inviability - when a hybrid cannot develop into a healthy adult or the zygote dies shortly after fertilization. Ex- sheep and goat has a shorter life span ○​ Hybrid breakdown - when the 22qfirst generation (F1) is viable and fertile but when the hybrid species mate with each other, or another parental species, the next generation F2 is weak or infertile. Ex- cotton and rice ​ Allopatric speciation (aka geographic isolation) ○​ Physical barriers like a mountain, ocean or canyon that separates populations may eventually lead to an inability to interbreed because the gene pool has been too different. Both groups are reproductively related ​ Sympatric speciation ○​ Same geographic location but reproductively isolated ○​ Happens due to prezygotic and postzygotic barriers ​ Peripatric speciation ○​ A small population becomes isolated on the edge of the main population leading to rapid genetic drift ​ Parapatric speciation  ○​ Adjacent population evolves into distinct species while maintaining a shared border where interbreeding is limited 8. Adaptive Radiation, Convergent, Divergent Evolution. ​ Divergent evolution ○​ Closely related species that have evolved different phenotypes ○​ Happens due to different environments or pressures ○​ Homologous features are generally seen in distinct species ○​ Ex grand canyon squirrels ​ Convergent evolution ○​ Unrelated or independent species that have independently evolved similar phenotypes ○​ Happens due to similar but unrelated environments or pressure ○​ Analogous features are usually seen in distinctly related or unrelated species (similar phenotypes ) ○​ Ex sharks (fish) and dolphins (mammal) live in similar habitats and have analogous features ​ Parallel evolution ○​ Related species that have independently evolved similar phenotypes ○​ Happens due to similar environments or pressures ○​ Ex flightless birds ​ Co - Evolution ○​ Mutualism: A relationship where both species benefit from each other's pressure. Ex flowers and pollinators ○​ Predators or prey - A relationship where one species (predators) hunts and feeds on another prey. Rough skinned newts and California's red-sided garter snakes ○​ Competition - A relationship where two or more species are competing for the same resources, driving adaptation to reduce overlap or increase efficiency. Ex- lions and hyenas, squirrels and birds ○​ Parasite or Host - A relationship where one species (parasite) benefits at expense of another (host), leading to defensive and offensive adaptations. Ex- cuckoo birds and host birds, ticks and mammals ​ Adaptive radiation - when a single species evolve into multiple distant species; ex- darwin finches (divergent evolution) ​ Gradual equilibrium- evolution as a slow and continuous process of change; transition of horse species from small multi toed animals to large single toed for 50 million years ​ Punctuated equilibrium - evolution occurs in rapid burst of change followed by long periods of stability ​ Triloboats, which show sudden changes in morphology after millions of years after radiation Biodiversity 1.​ Taxonomy and level of organization, Kingdom, Phylum… ​ Taxonomy: Linnaeus Classifications -​ The science of naming, identifying, and classifying species. -​ Relies on Observable traits (Morphology) Domain (eukarya, bacteria, archaea) Kingdom (plants, archaebacteria, eubacteria, protists) Phylum (ex. Chordoma) Class (ex. mammals) Order (ex. Primates) Family (hominidae) Genus (ex. Homo) Species (ex. Sapiens) 2.​ Eukaryotic vs. Prokaryotic Cells (info. and be prepared to label) 3.​ Viruses, Lytic Cycle, Bacteriophage parts Viruses: ​ Viruses do not meet the requirements for living things ​ They do contain nucleic acid (DNA, RNA) adapt to changing conditions (mutote)  ​ They cannot: reproduce on their own (need a host cell). Made up of protein coat and nucleic acids. NOT A CELL. Structures and Functions ​ Made of a short piece of DNA or RNA that’s surrounded by a protein coat. ​ Some viruses protein coat can merge with the host cell ​ Has a perfect structure to enter a host cell and reproduce ​ Bacteriophage (a virus that infects bacteria) Lysogeny ​ Some viruses have a dominant phase where they are inactive ​ Flow the injection of the nucleic acid into the host cell’s DNA ​ HIV is a virus that does this. That’s why some individuals will appear healthy/but actually have infection Nutritional Made: -​ Heterotroph: absorbs organic molecules from environment or eats others -​ Photoautotroph: uses sunlight to move CO2 into carbon compounds like sugar -​ Photoheterotroph: absorbs organic molecules from environment or uses light energy -​ Chemoheterotroph: uses energy released through chemical reactions involving ammonia, hydrogen, sulphide and others. 4.​ Prokaryotes- bacterial shapes, cell wall types, and gram-positive or negative, binary fission, conjugation and transduction Prokaryotes: ​ Includes ArChaea & Bacteria -​ Bacteria are alive. They grow, reproduce ​ 2 domains of life just for bacteria -​ Some are good and some are bad -​ Good- (ex. the ones in our gut) -​ Ex. Yogurt Cell Shape: 1.​ Spherical= cocci 2.​ Rod Shaped= Bacilli 3.​ Spiral Shaped= Spirochetes Colony Shaped= Bacteria are joined together 1.​ Strep= Chain of Bacteria 2.​ Staph= cluster, clump Gram-Positive; ​ Turns purple  ​ Cell wall with lots of Peptidoglycan Gram-Negative; ​ Turns pink ​ A thin peptidoglycan layer surrounded by an outer membrane 5.​ Protists- Diagrams of paramecium, euglena, amoeba- methods of movement, methods of eating (classification) Classification: 1.​ Animal-like protists called protozoans are heterotrophs that capture and ingest their food. * Amoebas use their pseudopods to capture and ingest prey. 2.​ Plant-like protists are autotrophs that make using their own food, often from sunlight, & CO2 using chloroplasts. *Algae 3.​ Fungus-like protists are heterotrophs that feed on decaying organic matter, as fungi do: Ex Slime molds, cellular slime molds, and water molds. 6.​ Fungi  ​ Fungi are heterotrophic eukaryotes that release powerful enzymes to digest organic matter outside of their bodies ​ They then absorb nutrients ​ They obtain oxygen from the environment as well Diversity of Fungi: ​ Fungi include mushrooms, molds, yeast, truffles, and rusts ​ More than 100,000 species that differ in size, shape, and color ​ Are important decomposers and sometimes parasites Structure and Function: ​ Yeasts are unicellular ​ Most bodies of fungi are made up of Hyphae (tiny threads of cytoplasm surrounded by a cell membrane and cell wall, differs from contains chitin, not cellulose) ​ Hyphae have cross-walls that divide the long filaments into separate end-to-end cells ​ This helps cytoplasm distribution and movement of nutrients ​ As they grow, the hyphae branches and forms a mycelium ​ In large mushrooms, the part of the mycelium above ground that we see is the: “fruiting body” ​ This mycelium extends below ground to increase nutrient absorption as they can’t move. Mycorrhizae ​ Vast networks of mycelia extend throughout many types of soil ecosystems ​ Often from mutualistic relationships with plant roots ​ Fungi gets sugar, scratch, lipid from roots and helps the plant collect phosphate. Sexual Reproduction 1.​ Fungi exhibit two different sexes called “+” and “-” 2.​ Opposite-sex hyphae will grow towards each other and fuse forming a diploid zygospore that have two sets of chromosomes 3.​ This helps increase genetic diversity in fungi as it has two sets of chromosomes. Major Groups of Fungi ​ Zygomycota- common molds ​ Basidiomycota- club fungi (button mushrooms) ​ Ascomycota- sac fungi (morels) ​ Chytridiomycota- chytrids, fungi with flagella 1.​ Protists- types of movement, ways of getting energy Types of movements: ​ Protists have a variety of methods of moving ​ Movement can be toward food or away from danger 1.​ Pseudopodia are used by amoebas; pseudopod= “False foot” 2.​ Flagella are long, hair-like projections 3.​ Ciliates use cilia, cilia are much smaller than flagella, and appear in groups or completely covering an organism. Cilia move together like tiny oars on the plasma membrane. 4.​ Passive movement by wind, water currents, or passing How protists reproduce: 1.​ Mitosis 2.​ Many protists reproduce by alternation of generations, alternating between haploid and diploid stages. Ex. slime molds, Trypanosoma brucei Protists= The Origin of Eukaryotes ​ The most common belief is a two-step process. 1.​ Infolding: where internal membranes formed from inwards fold of the plasma membrane of ancient prokaryotes. -​ Infolding formed structures like the endoplasmic reticulum, Golgi apparatus, and nuclear envelope. 2.​ Endosymbiosis occurred, where smaller prokaryotes were captured inside larger host cells. ​ Symbiosis occurred at first, evolving into the formation of organelles like mitochondria and chloroplasts. 2.​ Diagrams of bacteria, bacteriophage, protists 1.​ Eukaryotic vs. Prokaryotic Cells (info. and be prepared to label) Eukaryotic Cells: ​ Size: Larger (10-100 µm). ​ Nucleus: Have a membrane-bound nucleus where the DNA is stored. ​ Organelles: Contain membrane-bound organelles like mitochondria, endoplasmic reticulum, Golgi apparatus, and others. ​ DNA: DNA is organized into linear chromosomes inside the nucleus. ​ Cell Division: Eukaryotic cells divide by mitosis (for growth and repair) or meiosis (for reproduction). ​ Example Organisms: Found in animals, plants, fungi, and protists. Prokaryotic Cells: ​ Size: Smaller (0.1-5 µm). ​ Nucleus: No true nucleus. The DNA is free in the cell in a region called the nucleoid. ​ Organelles: No membrane-bound organelles (no mitochondria, ER, etc.). ​ DNA: DNA is usually a single, circular chromosome. ​ Cell Division: Prokaryotic cells divide by binary fission, a simpler process than mitosis. ​ Example Organisms: Found in bacteria and archaea. Similarities: ​ Both have a cell membrane that controls what enters and exits the cell. ​ Both contain ribosomes to make proteins. ​ Both contain DNA as genetic material.