Bio Exam Review 202 PDF

Bio Exam Review 202 Multiple Choice: ​ Unit 1 Binomial Nomenclature: first part of name is the genus, 2nd part is the species name. Italicized when typed, underlined when written. Viruses -​ contains DNA or RNA surrounded by a protein coat (the capsid)...

Bio Exam Review 202 Multiple Choice: ​ Unit 1 Binomial Nomenclature: first part of name is the genus, 2nd part is the species name. Italicized when typed, underlined when written. Viruses -​ contains DNA or RNA surrounded by a protein coat (the capsid) -​ one method used to classify viruses is by the size & shape of the capsid K. Fungi Structure -​ threadlike filaments (hyphae) -​ hyphae elongate & branch off to make a network (mycelium) -​ reproductive sys. Located above ground (fruiting body)- produces and disperses spores. k. bacteria - unicellular, prokaryotic - can be either aerobic or anaerobic - typically have cell walls - typically reproduce asexually (Binary fission) k. archaea -​ unicellular organisms -​ typically have cell walls -​ more archaea live in extreme environments -​ prokaryotic cells Cell Organelles - Function Nucleus: control center of cell, contains genetic material (DNA), surrounded by nuclear membrane Nucleolus: produces ribosomes, dense spherical structure in nucleus Nuclear Membrane: surrounds & protects nucleus, has pores that help control what enters/exits Centrosome: protects microtubules, involved in all cell division Cell Membrane: layer of fats that keep internal/external cell environment separated, semi-permeable, allow some substances in/out of cell depending on cell’s needs Golgi Body: use vesicles as packaging at edge of Golgi body, packaging of macromolecules for transport around/out of cell Mitochondria: produces energy (ATP), uses oxygen and glucose in the process of aerobic cellular respiration Vacuole: plays a role in intracellular digestion, release of cellular waste products, nutrient/waste storage, transportation, etc Cytosol: where metabolism and other specialized functions occur Rough endoplasmic reticulum: ribosomes on exterior, as ribosomes produce proteins, they are pushed inside the RER for processing  smooth endoplasmic reticulum: many different functions depending on type of cell Lysosome: contains enzymes to assist in digestion, breakdown and recycling of old cells, engulf bacteria and viruses, destroy cells Peroxisome: various functions, in plants they assist chloroplasts in photorespiration Ribosome: synthesize proteins, made from RNA, site of protein synthesis Cytoskeleton: various tubules that helps maintain structure of cell, help move organelles around the cell Flagella: aid the cell in moving one way or another Cilia: short hair like structures on outside of cell aid in transport Homologous Structures -​ chromosome that contains the same sequence of genes as another chromosome -​ may appear identical, but can carry different forms of the same genes at the same location Kingdom Animalia -​ radial symmetry: any longitudinal cut thru the midpoint yields equal halves -​ bilateral symmetry: only one longitudinal cut thru the midpoint yields equal halves (humans) -​ Mobile, multi-cellular, no cell walls, heterotrophic ​ Unit 2 ​ Cell Cycle -​ made of interphase (G1, S, & G2 phases) and Cell Division (divided into mitosis and cytokinesis) -​ ensures the parent cell provides an identical set of chromosomes in each of its daughter cells Phenotype: trait that is expressed in an organism Genotype: combination of 2 alleles for any given trait of an organism Allele: different form of same gene ( green vs brown eyes ) Homozygous: organism with 2 identical alleles of a gene Heterozygous: organism with 2 different alleles of a gene Unit 3 Blood Components -​ plasma (~55%), red blood cells (~44%), white blood cells and platelets (~1%) -​ Plasma: clear, yellowish fluid made up of water & dissolved proteins, carries other substances -​ RBC’s: have no nucleus. Each contain ~280 million molecules of hemoglobin, which bind & transport oxygen in the blood -​ WBC’s: fight infection by destroying pathogens, have a nucleus -​ Platelets: fragments of cells, play a key role in blood clotting  Pepsin -​ origin: stomach, where it acts & pH: stomach, 1-2, nutrient molecule digested: protein, products of digestion: peptides ​ Lipase -​ Origin: pancreas, where it acts & pH: small intestine, 8, nutrient molecule digested: lipids, products of digestion: fatty acids and glycerol Amylase salivary: origin: salivary glands, where it acts & pH: mouth, 7, nutrient molecule digested: starch, glycogen, products of digestion: maltose (disaccharide) Pancreatic: origin: pancreas, where it acts and pH: small intestine, 8, nutrient molecule digested: starch, glycogen, products of digestion: maltose Accessory Organs -​ secretions from liver & pancreas help digestion -​ liver produces bile, stored in the gallbladder (bile breaks down fat into smaller fat droplets) -​ pancreas produces enzymes and bicarbonate (bicarbonate raises the pH level so enzymes can function efficiently) Unit 4 Root Structures & Functions Roots: anchor the plant, absorb water & nutrients, store carbs Root Tips: contain meristematic cells, consist of parenchyma cells that protect growing tissue, secret slimy substance to reduce friction Outer Root Layers: root is covered by layer of dermal tissue, btwn the cortex and vascular tissue is the endodermis, each cell in it surrounded by the casparian strip Casparian Strip: barrier that forces water & dissolved minerals to cross the cell membrane and pass thru the cytoplasm Plant Tissues -​ Meristematic: undifferentiated, embryonic tissue found in areas of rapidly dividing cells, apical meristems cause primary growth (growing taller), lateral meristems cause secondary growth (growing wider) -​ Dermal: made up of epidermal cells and other specialized cells, covers exterior of plant -​ Epidermis: protects entire body of non woody plants & young woody plants -​ Guard Cells: control opening size of stoma -​ Trichomes: tiny hairs that reduce evaporation, some secrete toxic substances -​ Root Hairs: increase surface area for water & nutrient absorption -​ Ground: form most of a plants interior/exterior material, involved with photosynthesis, storage & support  -​ Parenchyma: t. Func - storage, gas exchange, photosynthesis, protection, tissue repair/replacement. -​ Collenchyma: elongated (celery string), unevenly thick walls, flexible. Func - support surrounding cells, tissue repair/replacement. -​ Sclerenchyma: very thick, tough secondary cell walls (apple core). Func - support mature plants. -​ Vascular: transport materials, divided into xylem and phloem, connects roots to leaves, arranged in bundles in non woody flowering plants Monocots: xylem cells form a ring around central core of cells, phloem cells surround Xylem cells in this ring Dicots: xylem cells form an X or star shape, phloem cells are btwn the arms of the star Plant Hormones Auxins stimulate cell division in stems & roots. Control a plant’s response to light & gravity. Cytokinins produce proteins used for cell division, promote rapid growth, prevent aging of leaves & fruit. Ethylene promotes ripening of fruit by weakening cell walls of unripe fruits, breaks down carbohydrates into simple sugars. Gibberellins stimulate cell elongation in shoots to promote stronger, taller plants. They “break” dormancy cycles in seeds & buds. Abscisic Acid keeps seed dormant, inhibits shoot & leaf growth, closes stomata, blocks action of other hormones. Parts of the Flower and their Functions sepal: protect flower bud Petal: attract pollinators Anther in stamen (M): produce pollen, contain sperm Pistil (F): F gametophytes in ovaries develop here Stigma (F): where fertilization takes place Unit 5 Species: Group of organisms that can interbreed and produce fertile offspring. Founder effect: small number of individuals move into a new area - called “founders”. Low frequency alleles (exist in small numbers) may be overrepresented in the founder population, which may increase in frequency causing the gene pool to change.Occurs on islands easily in natural populations. Bottleneck effect: changes in gene distribution that result from a rapid decrease in population size - could be due to starvation, disease, human activities, natural disaster, etc. Surviving organisms begin to grow the population, but with a much smaller gene pool (lower genetic diversity). Genetic drift: Description: Random change in genetic variation from generation to generation due to chance.Allele does not make the individual better suited to survive and reproduce Effect: Change’s frequency of alleles. In small  populations, it is less likely that the parent gene pool will be reflected in the next generation. In large populations genetic drift can still occur. Macroevolution: the change in allele frequencies that occur within a population, over time.They are due to mutation, selection (natural & artificial), gene flow, and genetic drift. Allele frequency: The percentage of any specific allele in a gene pool. Genetic equilibrium:In a population where allele frequency remains stable, over generations. Fitness: is measured by the number of offspring produced in the next generation that are viable (able to reproduce). A high degree of fitness means that an organism is more likely to survive and reproduce, thereby passing on its advantageous genes to its offspring. Selective advantage: is the genetic advantage of one organism over its competitors (a useful mutation). The advantage allows the organism to be favoured over others in survival and reproduction rates (over time) in a particular environment. Gene flow: Description: Net movement of alleles from one population to another, as a result of the migration of individuals. Occurs between two different interbreeding populations with different allele frequencies. Effect: May change allele frequencies in either or both populations through ‘flow’, or movement, of genes. Evolution: the process by which species change over time through processes like natural selection, gene flow and genetic drift. looking at a phylogenetic tree -​ branches close together: recent common ancestor short/long answer unit 1 Taxonomy hierarchy 1.​ domain 2.​ kingdom 3.​ phylum 4.​ class 5.​ order 6.​ family 7.​ genus 8.​ species Eukaryotic cells: membrane bound organelles, aerobic respiration, can reproduce both asexually and sexually Prokaryotic cells: contain ribosome, no membrane bound organelles, anaerobic respiration, their DNA is a single loop of double stranded DNA, asexual reproduction, cell division by binary fission  k. protista (junk drawer) -​ wildly different from each other -​ both unicellular and multicellular -​ some photo synthesize if they have green chlorophyll filaments -​ can be autotrophic or heterotrophic -​ can reproduce asexually and sexually Protists obtain nutrition via autotrophy (photosynthesis), heterotrophy (ingestion or absorption), or mixotrophy (combining both methods). They inhabit moist or aquatic environments. unit 2 mitosis -​ a cell’s copied genetic material separates and the cell prepares to split into 2 daughter cells -​ enables the cell’s genetic information to pass into the new cells prophase -​ chromatin condenses into chromosomes -​ each chromosome is made up of 2 identical sister chromatids joined at the centromere -​ nuclear membrane breaks down, nucleolus disappears -​ spindle fibres form from the centromeres ​ metaphase -​ spindle fibres guide chromosomes to the equator (center of cell) -​ spindle fibres attach to the centromere of each chromosome anaphase -​ each centromere splits apart, sister chromatids separate from each other -​ chromatids now referred to as chromosomes -​ spindle fibres pull chromosomes to opposite poles of cell telophase -​ nuclear membrane reappears, two daughter cells form codominance: when both alleles are expressed (cow is a heterozygote with both vase colour and white colour visible) Meiosis Purpose: produces gametes for sexual reproduction, reduces chromosome number by half. Phases: meiosis I - homologous chromosomes separate (Prophase I, Metaphase I, Anaphase I, Telophase I), meiosis II - sister chromatids separate (Prophase II, Metaphase II, Anaphase II, Telophase II) describe what happens during each phase Gametogenesis: formation of sperm (spermatogenesis) and eggs (oogenesis) End Products: four haploid cells unit 3 circulatory system functions -​ transports materials within the body -​ supports respiratory sys. (transporting oxygen to cells) and digestive sys. (transports nutrients to cells, eliminates waste) -​ helps regulate the body’s temperature -​ protects against blood loss and infection arteries -​ carry blood away from heart, walls have thick muscles to help move blood -​ most of them carry oxygenated blood to the tissues & organs of the body -​ small arteries: arterioles ​ veins -​ carry blood to the heart, less muscle in their walls, have valves to prevent blood from flowing backward -​ muscles surrounding the veins help keep blood moving forward -​ most of these carry deoxygenated blood to the heart -​ small veins: venules capillaries -​ one cell thick, where nutrients, gases, waste diffuse btwn the circ. sys. and body cells -​ arterioles connect to one end while venules connect to the other end how body regulates temperature vasodilation: blood vessels widen, increases blood flow, helps the body cool down by releasing heat vasoconstriction: blood vessels narrow, reduces blood flow, conserves heat to keep body warm -​ both processes controlled by nervous system to help maintain homeostasis unit 4 Leaf Structures & Functions -​ blade of simple leaf not divided into smaller parts, blades of compound leaves divided into smaller leaflets -​ a leaf’s venation is the pattern of the veins in the leaf -​ parallel: veins run parallel to the main vein and each other -​ pinnate: veins branch off along the central vein -​ palmate: veins branch off from a common point (maple leaf)  -​ opposite growth: 2 leaves attached to the stem directly opposite each other at the same level -​ alternate growth: leaves arranged in a step-like pattern on either side of the stem, each leaf at a different level -​ whorled arrangement: 3 or more leaves evenly spaced around a stem at same level Specialized Plant Cells Parenchyma Form: flexible, thin walled, spherical Function: storage, photosynthesis, gas exchange, protection, tissue repair and replacement Collenchyma Form: elongated (celery string), unevenly thick walls, flexible Function: support for surrounding cells, flexibility, tissue repair and replacement Sclerenchyma Form: very thick, tough secondary cell walls (apple core) Function: support for mature plants - most de once developed, losing their cytoplasm but retaining cell walls Balanced photosynthesis equation: 6CO2 + 6H2O → C6H12O6 + 6O2 Xylem -​ transports water from roots to leaves, made from tracheids in gymnosperms, made from tracheids & vessel element cells in angiosperms -​ fluids pass from one tracheid/vessel to the next thru the pits -​ when they mature, cell contents die, cell wall stays in place ​ Phloem -​ transports nutrients from leaves to rest of plant, can move up or down (or both at same time) on the plant -​ composed of sieve tube elements (alive at maturity, no nucleus) and companion cells (have nuclei, keep STE alive) Tropisms -​ a stimulus causing a plant to grow toward/away from it -​ positive is growth towards stimulus -​ negative is growth away from stimulus Phototropism: growth response to light stimulus (unequal distribution of hormone auxin - less auxin on the side of the plant towards the light, more on the side away from light, causing it to curve) -​ this causes cell elongation, stem: positively phototropic, roots: negatively phototropic Gravitropism: describes a response to gravity using auxins. -​ roots exhibit positive grav. (towards gravity/down) to anchor the plant and brings roots to the water & nutrients  -​ stems exhibit negative grav. (away/up) to get most access to the light Thigmotropism: growth response to mechanical stimuli (contact with object or another organism, wind) due to an unequal distribution of auxin. Nastic Response: flower that closes its petals at night and opens them during the day exhibits this. A reversible response to a stimulus that is not associated with the direction of the stimulus. Meristems Apical: at tips of roots and stems, cause growth in length (primary growth) Lateral: allow stems, trunks, and bark to become as] plant grows taller (secondary growth unit 5 variation: differences between individuals, may be structural, functional, or physiological selective pressure: environmental conditions that select for certain characteristics of individuals and select against other characteristics artificial selection: selective pressure exerted by humans or populations in order to improve or modify particular desirable traits natural selection: process by which characteristics of a population never change over many generations as organisms with heritable traits survive and reproduce, passing their traits onto offspring allopatric speciation: speciation in which a population is split into 2 or more isolated groups by a geographic barrier -​ isolation prevents gene flow, leading to divergence and formation of new species sympatric speciation: speciation in which populations within the same geographic region diverge and become reproductively isolated -​ often results from ecological isolation, behavioural differences, or polyploidy in plants Gene pool: the combination of all the genes (including alleles) present in a reproducing population or species. Theories of Lamarck and Darwin Lamarck -​ proposed that organisms change during their lifetime by using or not using certain body parts -​ suggested that acquired traits could be inherited by offspring (ex: giraffes stretching their necks to reach higher leaves) -​ theory was later disproved but introduced the idea that organisms adapt to their environments ​ Darwin -​ developed the theory of evolution by natural selection -​ key concepts: variation exists among individuals in a population, struggle for existence leads to survival of the fittest, favorable traits become more common over generations -​ published On the Origin of Species in 1859