Biology 1B - Final Exam
Identify the major characteristics of protists
- Paraphyletic = Protists are found in each of the 6 supergroups - Often more closely related to another group (plants, animals, fungi) than to each other - Extremely diverse - Domain Eukarya - Amoeboid and ciliates possess unique organelles, such as contractile vacuoles - Asexual reproduction - binary fission - Sexual reproduction - meiosis and fertilization
Distinguish between primary growth & secondary growth in plants
- Primary growth: the increase in length of the shoot and the root. Secondary growth or "wood" is noticeable in woody plants; it occurs in some dicots, but occurs very rarely in monocots. - Secondary growth: an increase in thickness or girth of the plant, and is caused by cell division in the lateral meristem. Herbaceous plants mostly undergo primary growth, with hardly any secondary growth or increase in thickness.
Compare the three hypotheses about how viruses evolved
- Regressive Hypothesis: the "devolution" from free-living cells - Progressive Hypothesis: nucleic acid molecules "escaped" from cells - Virus-First Hypothesis: the first self-replicating molecules
Explain how photoreceptors function differently from other receptors
- Rods: outer edges of retina; strongly photosensitive = detect dim light -used for peripheral & nighttime vision - Cones: center of retina; weakly photosensitive = respond to bring light - used for color vision in daytime - Transduction of Light: Light → photoreceptor → shape change →closing of Na+ channels → hyperpolarization→ optic nerve → brain
Describe how water potential, transpiration, & stomatal regulation influence how water is transported in plants
- Transpiration: the main driver of water movement in the xylem, caused by the evaporation of water at the leaf-atmosphere interface, leaves are covered by a waxy cuticle on the outer surface that prevents the loss of water - Stomatal Regulation: regulation of transpiration, therefore, is achieved primarily through the opening and closing of stomata on the leaf surface
Describe the characteristics of the invertebrate chordates
- subphyla urochordates, cephalochordates - do not possess a defined bony vertebral endoskeleton, or a bony cranium. - hemichordates have a dorsal nerve cord in the midline of the epidermis, but lack a neural tube, a true notochord and the endostyle and post-anal tail characteristic of chordates
Compare & contrast active & passive immunity
Active - Long-term - Memory cells - Natural or artificial Passive - Short term - Antibodies - Natural or artificial
Describe the derived characteristics in birds that facilitate flight
Adaptations for flight: - Feathers - modified scales - Hollow bones - Keel-shaped sternum: allow for wing muscles - Efficient respiration - Lack true bladder = Cloaca - Females - only one ovary
Describe the functions of the structures of the human eye
Anatomy of Human Eye - Retina: inner surface of back ofeye; transduction of light Fovea: sharp vision - Cornea: front transparent layer of the eye; refract (bend) light to focus image on retina - Lens: transparent convex structure behind cornea; refract (bend) light to focus image on retina Stretched or thickened by muscle contraction → hyperopia & myopia - Iris: muscular ring between lens &cornea; regulates amount of light
Describe the evolutionary history & main characteristics of amphibians
Ancestors - Bony Fish (Ray-finned and Lobe-finned) Gill → swim bladder → lungs Ex: Tiktaalik Intermediate form Feet-like fins attached to shoulder○ Wrist joints Gills and lungs Neck Ribs Eyes on top of head Scales Pelvic girdle
Identify the characteristics of gymnosperms & angiosperms including their general life cycles
Angiosperm: - Monophyletic phylum - Anthophyta - Heterosporous - Sporous dominant - Flower - pollination and embryo protection - Fruit - seed protection and dispersal Gymnosperm: - Gymnosperms still dominate some ecosystems, such as the taiga (boreal forests) and the alpine forests at higher mountain elevations because of their adaptation to cold and dry growth conditions. - Lack flowers and fruit - Naked seeds, protected by sporophylls Heterosporous - - Male - (Micro) gametophyte - Female - (Mega) gametophyte - Alternation of generations - dominant sporophyte - diploid
Identify the molecules for short-term & long-term energy storage in animals
Animal Bioenergetics Energy Storage: - Short-term: glycogen - Long-term: adipose
Discuss the distinguishing features of sharks & rays compared to other modern fishes
Cartilaginous Fish (Chondrichthyes): - Have Jaws - Evolution of Teeth - Mostly predators - Evolutionary reversal from Bony Fish Ex: Sharks, Rays, Skates Unique Characteristics: - Ampullae of Lorenzini: detect electromagnetic fields of living organisms - Lateral line: detects movement and vibrations in water - Elasmobranch: exposed gill slits
Define evolutionary fitness
Change in allele frequency within a population: (1) Mutation - create genetic variation, random error in DNA replication during cell division or as a result of exposure to mutagens or viruses - Asexual organisms: binary fission 🡪 mutations are always passed on and are main source of genetic variation - Sexual organisms: mutations must occur in the gametic cells to be passed on (2) Genetic Drift - random sample of alleles present in population make it into the next generation, can lead to the elimination of an allele from a population by chance, little effect in large populations - Bottleneck: A chance event or catastrophe can reduce the genetic variability within a population. Survival is random and not based on any traits. - Founder Effect: Reduced genetic variation from the original population due to a non-random sample of the genes in the original population (3) Gene Flow - Individuals from one population migrate into a different population changing the allele frequencies within the population - Immigration: new individuals come into a population• - Emigration: individuals leave a population (4) Non-random mating - Not based on factors within the environment, does not lead to adaptations, causes change in allele frequencies within a population (5) Natural selection (Adaptive Evolution) - acts on heritable traits within a population, selects for beneficial alleles that allow for environmental adaptation, natural selection acts on individuals to affect change in a population, Individuals do not evolve, Populations evolve - Stabilizing selection, Directional selection, Diversifying selection
Describe what scientists know about the origins of eukaryotes based on the last common ancestor
Characteristics of Eukaryotic Common Ancestor 1. Cells with nuclei 2. Mitochondria 3. Cytoskeleton 4. Flagella and cilia 5. Chromosomes organized by histones 6. Mitosis 7. Sexual reproduction and meiosis 8. Cell walls
Describe the key features of the phyla Annelida
Coelomates Segmented worms: repeated body segments Most advanced worms Closed circulatory system Complete digestive system No respiratory: need moist environments Primitive kidney Nervous system
Relate bioenergetics to body size, levels of activity, & the environment
Energy requirements: - Activity level: 2-4 times BMR/SMR Environmental conditions: - Torpor: Slow down metabolism (estivation and hibernation) Body size: - Small animals lose energy faster than big animals - Cell size is constrained by surface area to volume ratio - Increase size, decrease ratio →decrease in efficiency of diffusion - Heterotrophic: obtain energy and nutrients from other organisms - Converted to ATP for anabolic reactions
Describe the evolution of the ear bones in mammals
Evolution of Ears Fish: gill arches > jaws - Amniotes: Pharyngeal arches First pharyngeal arch → jaw and ear Second pharyngeal arch → ear
Explain & provide examples of temporal, habitat, & behavioral isolating mechanisms
Prezygotic barriers - Temporal isolation: species have different breeding schedules - Habitat isolation: members of species move to a new habitat within the same area or are otherwise separated - Behavioral isolation: certain actions or behaviors (or the lack of them) impacts reproduction - Physical isolation: Differences in the gametes prevent fertilization from occurring, Differences in the reproductive organs
Distinguish between prezygotic & postzygotic barriers to reproduction
Prezygotic barriers: adaptations that reduce the likelihood of inter-species breeding. Postzygotic barriers: Prevents the formation of fertile offspring
Compare & contrast primary & secondary immune responses
Primary Immune Response: Vaccination is based on the knowledge that exposure to noninfectious antigens, derived from known pathogens, generates a mild primary immune response. Primary immune response refers to any immune response of the immune system that includes the production of antibodies and/or cell-mediated immunity. Secondary Immune Response: Secondary immune response refers to any immune response of the immune system that occurs in response to the subsequent exposure to a particular antigen
Describe prions & their basic properties
Prions (Proteinaceous Infectious Particles): - Smaller than viruses; made of proteins; infectious particles - Contain no nucleic acid - Cause fatal neurodegenerative diseases EX: - mad cow disease - Creutzfeldt-Jakob disease (in humans) - Kuru (in humans, spread by cannibalism) - Scrapie (in sheep) - Chronic wasting disease (in deer, moose, elk)
Name & describe the distinguishing features of the three main groups of mammals
(1) Order Monotremes - Ex: Platypus, echidnas - Lay feathery eggs - No teeth - Sweat milk (2) Order Marsupials - Embryo continues development in external structure (ex: pouch) - Ex: kangaroo (3) Order Eutherians - Most mammals - Placental mammals, Chorioallantoic placenta, derived from extra embryonic components of the amniotic egg
Explain the transmission of plant & animal viruses
(Plant Viruses) - Horizontal Transmission: virus typically enters by way of damaged plant tissue, may come from pollen, another plant, or vectors such as insect bites - Vertical Transmission: virus is transmitted from the parent plant (Animal Viruses) -A virus must use the host-cell processes to replicate. 1. Attachment: Receptors on the surface of the host cell bind to virus capsid proteins or virus envelope glycoproteins, viruses can attach only to cells that have the right receptor molecules, viruses can be very specific about what species or cell type they can infect 2. Entry: Bacteriophage DNA enters the host cell "naked," eukaryotic cells take up viruses through endocytosis or, if enveloped, by fusion with the cell's membrane 3. Replication/ Assembly (a) DNA genome - transcribe mRNA → make viral proteins duplicate DNA to make new viral genomes (b) RNA genome - make complementary RNA if necessary transcribe mRNA → make viral proteins copy RNA to make new viral genomes (c) RNA retrovirus - reverse transcribe RNA to make DNA, using reverse transcriptase, DNA incorporates into host genome, DNA directs synthesis and assembly of new viruses 4. Egress: Release of new virions in the host organism, usually involves lysis and death of the host cell, may involve budding, which does not directly kill the host cell
Identify the main characteristics of bryophytes
- >25,000 species of bryophytes in mostly damp habitats - Generally lack lignin and do not have tracheid - Commonly called nonvascular plants - Dominant gametophyte: sporophyte is small and supported by gametophyte - Three phyla: Hepaticophyta (Liverworts), Anthocerotophyta (Hornworts), and Bryophyta (Mosses) - Reliant on water for reproduction - No roots, leaves, stems Bryophytes are still dependent on water because: - The flagellated sperm must swim to the egg for fertilization - Absorption of water and nutrients occur across the surface of the gametophyte Nonvascular plants (Bryophytes) made initial transition from water to land but still - Non-vascular and non-tracheophyte require a moist environment - Lack lignin-reinforced conducting cells - Require water for reproduction - Absorb nutrients and water through their surface (no roots) - Small sizes due to lack of structural support
Know & recognize the assumptions of the Hardy-Weinberg principle (there will not be any problems to solve)
- A population's allele and genotype frequencies are inherently stable - unless an evolutionary force is acting upon a population (not true for most populations) - Genotype Frequency (p^2 + 2pq + q^2 = 1) - Allele Frequency (p+q=1) 2pq = Heterozygous allele p^2 = Homozygous Dominant allele p = dominant allele frequency q = recessive allele frequency q^2 = homozygous recessive allele
Compare & contrast allopatric, peripatric, parapatric, & sympatric speciation
- Allopatric speciation: differing environmental pressures benefit different adaptations, individuals leave origin allocation, natural barrier divides a population - Peripatric speciation: Occurs when a new colony starts with a small population - Parapatric speciation: No specific barrier to gene flow, species is spread out over a large geographic area, the population does not mate randomly (Individuals are more likely to mate with their geographic neighbors), common in oceanic species due to lack of barriers - Sympatric speciation: Occurs when two populations within the same physical location and conditions become unable to interbreed due to reproductive isolation, can be caused by errors in meiosis or factors that create reproductive isolation
Describe the different ways protists can gain energy
- Amoebas ingest particles through phagocytosis - Saprobes feed on dead organisms or their waste - Many protists are symbionts (ranges from strict parasitism to mutualism, coral reefs greatly aided by symbiotic photoautotrophic protists in tissues of corals - Mixotrophs can be both photoautotrophic and heterotrophic depending on availability of sunlight or organic molecules
Identify the characteristics of Superphylum Lophotrochozoa
- Bilateral - Triploblastic - Protostomes
Compare & contrast the biological, morphological, phylogenetic, & ecological species concepts
- Biological species: the ability of two individuals to successfully produce viable, fertile offspring - Morphological species: physical similarities - Phylogenetic species: how closely related individuals are evolutionarily - Ecological species: whether the individuals use or can use the same set of biological resources (occupy the same "niche")
Identify the characteristics of Superphylum Deuterostomia
- Blastopore: anus-first group - Triploblastic - True coelom - Bilateral symmetry - Radial cleavage - Indeterminate cleavage - Primitive dorsal nervous system Dorsal (Back) - Primitive ventral circulatory system Ventral (Belly/Front Side) - Shared characteristics with protostomes: bilateral symmetry, coelomate, triploblastic
Describe the three types of macronutrients in your diet
- Carbohydrates - Protein - Lipids
Describe the new traits that appear in seedless vascular plants
- Depend on water during fertilization, as the flagellated sperm must swim on a layer of moisture to reach the egg. Ferns and their relatives are more abundant in damp environments. - Xylem is the tissue responsible for the storage and long-distance transport of water and nutrients, as well as the transfer of water-soluble growth factors from the organs of synthesis to the target organs. The tissue consists of conducting cells, known as tracheid, and supportive filler tissue, called parenchyma. - Phloem is the second type of vascular tissue; it transports sugars, proteins, and other solutes throughout the plant. Phloem cells are divided into sieve elements (conducting cells) and cells that support the sieve elements. - The appearance of true leaves improved their photosynthetic efficiency. Leaves capture more sunlight with their increased surface area by employing more chloroplasts to trap light energy and convert it to chemical energy, which is then used to fix atmospheric carbon dioxide into carbohydrates.
Explain the different ways natural selection can shape populations using the terms directional, stabilizing, & diversifying selection
- Directional selection: a change in the environment shifts the spectrum of phenotypes observed - Stabilizing selection: an average phenotype is favored - Diversifying selection: two or more extreme phenotypes are selected for, while the average phenotype is selected against
Identify the kingdom most closely related to fungi & their common ancestor
- Domain Eukarya - Molecular data tells that animals and fungi shared a common ancestor after plants evolved (Flagellated unicellular protist was most likely the common ancestor)
Identify the unique characteristics of phylum Acoela
- Eumetazoa: Bilateria - Includes Phylum Platyhelminthes (flatworms) - Triploblastic: Not a protostome or deuterostome (blastopore closes during development) - Simple Nervous System - Nerve net - No digestive tract - Not protostome or deuterostome - Unique Embryonic Development: one cell divides into two cells each of which then divide into more cell - Slightly Cephalization - concentration of nerves in cranium - Basal Group: Diverge early and haven't evolved much since
Compare gradual speciation & punctuated equilibrium
- Gradual speciation: species diverge gradually through time with small steps - Punctuated equilibrium: species exhibit a large change in a relatively short period of time followed by long periods of stasis
Adaptive Immunity
- Highly specific - Has memory - Delayed response: days-weeks - Triggered by innate immune system Adaptive Immune Response: - Innate immune cells respond to pathogen - Phagocytic cell digests pathogen and presents antigen - Antigen-presenting cell alerts helper T cell → both release cytokines - Cytokines cause helper T cells to clone themselves - Cloned T cells produce cytokines that activate other T and B cells → stimulates humoral and cell-mediated immune responses - T cells are produced by bone marrow → mature in thymus → inactive cells can be found in spleen, tonsils, lymph nodes, bloodstream - Cytotoxic (killer) T cells: kill infected cells - Suppressor T cells: deactivate T and B cells - Cell mediated - Humoral - B cells (towards end of infection, change into memory cells) Memory cells: remember specific antigen to speed up future immune responses; differentiate into plasma cells after reinfection - Neutralization: block pathogens from binding to cells → pathogens filtered from blood spleen - Opsonization: tagging of pathogens for phagocytosis - Complement Activation: antibodies bind to pathogen and attract complement proteins → create holes in pathogen membrane
Describe reinforcement, fusion, & stability as changes in a hybrid zone over time
- Hybrid zones: area where two closely related species interact and interbreed - Reinforcement: process where hybrids are less fit, and thus there is a nudge towards further divergence between the two species
Describe the distinguishing characteristics of phylum Echinodermata
- Larva stage: bilateral symmetry - Adult stage: pentaradial symmetry - Water vascular system from true coelom - Ossicles: true endoskeleton - Complete digestive system - Reduced nervous and circulatory system - Organisms: Sea star, Brittle stars, Sea urchins, Sea lilies, Sea cucumbers
Innate immunity
- Non specific - No memory - Always working, looking for pathogens in the body - Triggers adaptive immune system - All animals & maybe plants Physical & Chemical Barriers: - Skin: pH, microbiome - Nasal passage & respiratory tract: tears, mucus secretion, cilia - Stomach: acid, enzymes Cytokine: chemical messenger that regulates differentiation, proliferation, and gene expression (protein produced by lymphocytes = inflammation, due to movement of immune cells and fluid) - Interferon - viral infections and cancer cell surveillance, signals cells to undergo apoptosis, activates immune cells - Cytokine Release Effect: PRR binds with PAMP → release of cytokines → pathogen present - Macrocytes: Macrophages, dendritic cells = phagocytosis - Histamine - promotes permeability - Natural Killer Cells: lymphocytes, type of leukocyte, targets cancer cells or affected cells to be killed off by a phagocytic cell - Complement System: Array of 20 proteins - destroy extracellular pathogens, alert phagocytic cells, bind to surface pathogens
Identify the basic structures found in viruses
- Nucleic acid core: DNA (double stranded or single stranded) or RNA - Protein capsid coating protecting the genetic material - Most have glycoproteins that help the virus attach to host cell - Some have an outer envelope - Some have additional proteins such as enzymes The virus core contains the genome: - either DNA or RNA (but not both) - may be single-stranded or double-stranded - may be circular or linear - may be in one piece or in multiple segments
Describe the distinguishing characteristics of chordates
5 Key Characteristics (1) Notochord: a flexible, rod-shaped mesodermal structure that is found in the embryonic stage of all chordates and in the adult stage of some chordate species - located between the digestive tube and the nerve cord, and provides rigid skeletal support as well as a flexible location for attachment of axial muscles - The notochord acts as the primary axial support of the body throughout the animal's lifetime (2) Dorsal hollow (tubular) nerve cord - derived from ectoderm that rolls into a hollow tube during development (3) Pharyngeal gill arches or slits - are openings in the pharynx (the region just posterior to the mouth) that extend to the outside environment - In aquatic environments, pharyngeal slits allow for the exit of water that enters the mouth during feeding. - Vertebrate fish: the pharyngeal slits are modified into gill supports, and in jawed fishes, into jaw supports. - Tetrapod: the slits are highly modified into components of the ear, and tonsils and thymus glands. (4) a post-anal tail - Aquatic Species (such as fish): is a posterior elongation of the body, extending beyond the anus. The tail contains skeletal elements and muscles, which provide a source of locomotion in - Terrestrial Vertebrates: the tail also helps with balance, courting, and signaling when danger is near - Humans + apes, the post-anal tail is reduced to a vestigial coccyx ("tail bone") that aids in balance during sitting. (5) Endostyle/Thyroid Gland: - Produces substances similar to thyroid hormones and is homologous with the thyroid gland in vertebrates - A strip of ciliated mucus-producing tissue in the floor of the pharynx - Food particles trapped in the mucus are moved along the endostyle toward the gut
Describe oncogenic viruses
A virus that can cause cancer through mechanisms such as alteration of cellular genes, mutation, or the manipulation of genes and how they're expressed EX: hepatitis C, human papillomavirus (HPV)
Describe a cline
A measurable gradient in a trait of a species across its geographical range
Describe the evolutionary history of birds & their closest living relatives
Archosaurs = Dinosaurs (Basal Group) Pterosaurs (not dinosaurs, more similar to birds, convergent evolution) Evolution of Birds: Diapsid→ Archosaurs → Saurischia → Theropods
Discuss asexual & sexual reproduction methods
Asexual reproduction Bacteria Sponges Flatworms Annelids Echinoderms Whiptail Lizards Features: - Genetic clones - Produce large numbers of offspring quickly - Good in a stable environment - Makes colonization of new habitats easier Binary fission: prokaryotes & some eukaryotic unicellular & multi-celled organisms Budding: outgrowth of a part of cell or body Fragmentation: breaking of body parts Parthenogenesis: unfertilized egg develops into complete individual -haploid or diploid Sexual Reproduction - Egg+ sperm = offspring - External: aquatic environments - Internal fertilization - terrestrial environments: Oviparity: eggs laid outside parent's body Ovoviviparity: eggs retained in parent Viviparity: placenta - Dioecious & monoecious
Describe reproduction of prokaryotes & horizontal gene transfer in bacteria
Asexual reproduction via binary fission Horizontal Gene Transfer: - Conjugation: cell-to-cell contact - Transduction: by bacteriophages - Transformation: from the environment
Identify the characteristics of Superphylum Ecdysozoa
Bilateral, triploblastic protostomes Unique Characteristics: Cuticle (external covering), Ecdysis (molting)
Explain the structure of arteries, veins, & capillaries, and how blood flows through the body
Blood Connective Tissue - Matrix: plasma - Cells: RBCs, WBCs, platelets Functions: - Transportation - Regulation - Protection Red blood cells = Erythrocytes - Vertebrates: RBCs contain hemoglobin & iron = red blood - Arthropods: copper-based hemocyanin = blue blood - Most mammals: mature RBCs lack nucleus & mitochondria White blood cells = Leukocytes - Immune system: can migrate out of of capillaries into tissues - Nucleated, no hemoglobin Blood Vessels Arteries: blood from heart to body - Thick walls, high pressure - 4 Layers of tissue: endothelium, elastic fibers, smooth muscle, and connective tissue → no exchange of materials Veins: blood from body to heart - Thin walls with valves - 4 Layers of tissue: endothelium, elastic fibers, smooth muscle, and connective tissue → no exchange of materials Capillaries: site of exchange of blood & CO2 - Single layer of endothelial tissue → rapid exchange of gasses and metabolites between blood and body cells - Arteries → Arterioles → Capillaries → Venules → Veins Blood Pressure Pressure against the walls of a blood vessel - Systolic: ventricle contraction - Diastolic: ventricular relaxation Blood flow is regulated by: - Hormones: ADH - Size of blood vessels - Action of smooth muscles - One-way valves
Describe the two major innovations that allowed seed plants to reproduce in the absence of water
Bryophytes began initial colonization of land - Liverworts → mosses → ferns - Still required water for reproduction Gymnosperms and Angiosperms = seed plants - Evolved from spore-bearing plants known as pro gymnosperms - Angiosperms (flowering plants) are the most recently evolved plants lower vascular plants, such as club mosses and ferns, are mostly homosporous (producing only one type of spore) all seed plants, or spermatophytes, are heterosporous, producing two types of spores: megaspores (female) and microspores (male).
Compare & contrast convergent & divergent evolution & examples covered in this course; include homologous & analogous structures
Convergent Evolution: When similar traits evolve independently in species that do not share a common ancestor. EX: The white winter coat of the arctic fox and the ptarmigan's plumage are adaptations to their environments Divergent Evolution: Two species evolve in diverse directions from a common point. EX: Flowering plants evolved from a common ancestor but have very different reproductive organs. Homologous Structure: Skeletons of different animals are similar in structure, even if they vary in function. They arose from the same structures in a common ancestor. EX: bird wings and bat wings Analogous Structure: Similarity in structures due to environmental factors, not common ancestry EX: Insect wings and bat wings
Define evolution & describe the forces that can cause evolutionary change within a population
Definition: - Change in the heritable characteristics of a population over succeeding generations - Change in the gene pool of a population, measurable as changes in the allele frequencies in a population - Unifying theory of biology - Origin of species not the origin of life Characteristic of Evolution: (1) Change overtime in traits within a population (2) Common ancestry Evidence of Evolution: (1) Fossil record: show change over time (2) Homologous structures: skeletons of different animals are similar in structure, even if they vary in function EX: bird wings and bat wings (3) Molecular Biology (4) Biogeography (5) Vestigial Structures: Structures with no apparent function, Residual parts from a past ancestor
Describe the evolutionary relationships between the three domains
Domain Eukarya, Domain Archaea, Domain Bacteria - Bacteria and Archaea are both prokaryotes but differ enough to be placed in separate domains - An ancestor of modern Archaea is believed to have given rise to Eukarya, the third domain of life Domain Archaea vs. Domain Bacteria Plasma Membrane: Archaea (branched and have ether bonds), Bacteria (lipids are unbranched and have an ester linkage) Cell Wall: Archaea (peptidoglycan), Bacteria (peptidoglycan) Gene Expression: Archaea (transcription and translation are more similar to those of eukaryotes)
Describe general fungal morphology, life cycle, & metabolic traits
Fungal Morphology: - Mycelium: mass of hyphae; vegetative stage - Hyphae: long, branching filamentous structures; excrete digestive enzymes into the environment and then absorb nutrients - Fruiting body: reproductive structure Life Cycle: Most fungi are haploid for the majority of their life cycle Metabolic Traits: Heterotrophic: obtain C and N from food External digestion: digestion occurs before ingestion - Enzymes secreted from hyphae to process nutrients in the environment - Smaller molecules are absorbed through the large surface area of the mycelium Decomposers: break down insoluble polysaccharides → glucose - Saprophytic: nutrients from decaying organic matter Mutualists: mycorrhizal fungi form relationships with plants - Fungi gain sugars - Plants gain water and nutrients Parasites: infect animals or plants Store carbohydrates as glycogen
Describe the different ways animals perform gas exchange
Gas Exchange - One of the major physiological challenges facing all multicellular animals is obtaining sufficient oxygen and disposing of excess carbon dioxide - Gills: aquatic respiration: thin, highly folded tissue filaments that allow diffusion of dissolved oxygen - Skin: cutaneous respiration: dense network of capillaries below the skin; moist environments - Tracheal system: Most direct & efficient respiratory system Gas exchange - Avian - Flight requires high amount of energy & CO2 - Small lung & 9 air sacs; no diaphragm - Trachea → Posterior Air sacs → Lungs → Anterior Air - Sacs (Air sacs inflate not lungs) - Unidirectional air flow requires two cycles of air intake & exhalation to completely expel air from lungs More efficient at gas exchange Gas exchange - Mammalian Fish: primary gills, some lungs Terrestrial animals: lungs - Covered in mucus to prevent direct contact of lung tissue & air - Air picks up water from mucus → humidified - Cilia, hairs, mucus remove particulate matter Transport of oxygen - Hemoglobin (Hb): proteins found in RBCs Transport of Carbon Dioxide: - Returning to lungs from body tissue - More soluble in blood than oxygen 1. Dissolution 2. Transport 3. Bicarbonate buffer system
Describe genetic drift & the founder effect
Genetic Drift: can lead to the elimination of an allele, more impactful in smaller populations. Founder Effect: reduced variation in genetics due to small populations in isolated locations.
Describe the transitional traits of progymnosperms
Gymnosperms and Angiosperms = seed plants - Evolved from spore-bearing plants known as progymnosperms - A transitional group of plants that superficially resembled conifers (cone bearers) because they produced wood from the secondary growth of the vascular tissues; however, they still reproduced like ferns, releasing spores into the environment. At least some species were heterosporous.
Describe the roles that Hox genes play in development
Homeobox genes - "Master" regulatory genes that control embryonic development, turn on or off large numbers of other genes - genes with homeoboxes encode protein transcription factors. - Hox genes: a group of animal genes containing homeobox sequences - This cluster of genes is responsible for determining the general body plan, such as the number of body segments of an animal, the number and placement of appendages, and animal head-tail directionality. - The order of the genes reflects the anterior-posterior axis of the animal's body. - Contributions to increased animal body complexity is that Hox genes have undergone at least two and perhaps as many as four duplication events during animal evolution, with the additional genes allowing for more complex body types to evolve. Ex: A single Hox mutation in the fruit fly can result in an extra pair of wings or even legs growing from the head in place of antennae (because antennae and legs are embryologic homologous structures)
Explain antagonistic hormones
Hormones that act to return body conditions to within acceptable limits from opposite extremes
Discuss the different types of skeletal systems found in animals
Hydrostatic: - Animal anchors itself to substrate - Muscles contract against the coelom & change its shape - Pressure of the fluid in the coelom produces movement - Annelids - Longitudinal & circular muscles segments (1) Contraction of circular muscles elongates segments → pushing them forward (2) Contraction of longitudinal muscles shortened the segments → pulling trailing segments forward - Nematodes - Longitudinal muscle Exoskeleton: - Hard encasement - Function: defense, support, movement, prevent desiccation - Muscles anchored into exoskeleton → movement of joints - Ecdysis Endoskeleton: -Hard, mineralized structure with soft tissue - Function: support, protection, movement - Porifera: spicules - Echinodermata: ossicles or test covered by epidermis
Describe the evolutionary history & main characteristics of reptiles
Includes Birds - within the same clade Tetrapods Calcareous - leathery eggs laid on land Ectotherms - rely on outside temperature, lower metabolism = require less energy Scaly skin - reduces water loss Sexual reproduction with internal reproduction: - Ovoviviparous: Nutrients are supplied by the egg yolk, while the chorioallantois assists with respiration. - Viviparous: the offspring born alive, with their development supported by a yolk sac-placenta, a chorioallantois-placenta, or both - Order Crocilla (Alligator, crocodiles, gharias, caimans) - Order Sphenodontia ("Wedged Tooth," Tuatara = no ear holes - no external ears) - Order Squamata (Lizard, snakes, "Having scales") - Order Testudines ("Having shell," Tortoise, turtle)
Compare & contrast different types of digestive systems in animals
Incomplete - one opening (Gastrovascular cavity) - Ex: planaria - Lacks specialized structures Vertebrate Digestive System: Alimentary canal Monogastric = single chambered stomach - Includes: Animals, dogs, cats, and pigs - Diet high in energy and low in fiber Avian - Flight = high metabolic rates → fast digestion - Lack teeth - Crop: stores food - Two chambered stomach: Gizzard: mechanically breaks down food Proventriculus: enzymes - Cloaca: open opening for feces, urine, reproduction Ruminants - Includes: Cows, sheep, goats - Large amounts of cellulose - Rumination = "chewing the cud" Chew food more than once - breaks down fiber rich foods - Four-chambered stomach (Due to high fiber diet) Rumen: food storage and fermentation Reticulum: shorts based on size Cud returns to mouth - Omasum: water absorption - Abomasum: true stomach Digestive enzymes, acid, mucus Pseudo- ruminants (Hind-gut fermenters) - High-fiber diet - Includes: camels, alpacas, rabbits - Three chamber stomach - Monogastric - Digestion occurs in cenum and intestine Cenum: pouched organ at beginning of large intestine - Rabbits digest their foods twice Coprophagy: eat poop All lagomorphs undergo this process of digestion
Describe the evolution of jaws, gills, lungs, & limbs
Jaw Evolution: Jaws were probably derived from the first pair of gill arches supporting the gills of jawless fishes.
Identify the characteristics & examples of Agnathans & Gnathostomata
Jawless Fish (Infraphylum Agnathan) - Lack jaws - Lack paired lateral appendages (fins) Ex: Hagfish, Lampreys Jawed Fish (Infraphylum Gnathostomes) - 2 sets of paired fins - Jaws: more feeding opportunities - Chondrichthyes: cartilaginous fish - Osteichthyes: bony fish
Describe the challenges to plant life on land & the adaptations that allowed plants to colonize the land
Land plants evolved from aquatic green algae protist - Archaeplastida gained photosynthesis through endosymbiotic relationship with green, photosynthetic bacteria (1) Avoid desiccation - Desiccation, or drying out, is a constant danger for an organism exposed to air. Even when parts of a plant are close to a source of water, the aerial structures are likely to dry out. (2) Structural support - Water also provides buoyancy to organisms. On land, plants need to develop structural support in a medium that does not give the same lift as water. (3) Capture sunlight and avoid mutagenic radiation - The organism is also subject to bombardment by mutagenic radiation, because air does not filter out ultraviolet rays of sunlight. (4) Dispersal of reproductive cells - the male gametes must reach the female gametes using new strategies, because swimming is no longer possible. Therefore, both gametes and zygotes must be protected from desiccation.
Identify the derived characters of craniates that sets them apart from other chordates
Other chordates have a brain and eyes, as do vertebrates, but lack the skull found in craniates
Describe the passage of air from the outside environment to the lungs
Lung Structure: - Nasal Activity: warms & moistens air - Pharynx → larynx → trachea Smooth muscles and cartilage rings - Lungs → Bronchi → Bronchioles → Alveoli Gas exchange occurs in alveoli via diffusion into capillaries: O2 into blood & CO2 out of blood Lung Function Lung inflation - Intercostal muscles contract → expands rib cage - Diaphragm contracts → increases volume of thorax & lungs - Creates negative pressure → draws air into lungs Lung exhalation - Passive event - Muscles relax - Diaphragm moves higher into thoracic cavity
Identify the major hormones involved in female & male reproductive function
Male Reproductive System - Scrotum: houses testes - Testes: produce sperm & reproductive hormones - Sperm are immobile at body temperature - Seminiferous tubules (production) → epididymis (maturation) → vas deferens → seminal vesicles & glands (basic pH solution, mucus, fructose, enzymes, hormones) → penis - Prostate gland: connects to urethra; produces nutrients & enzymes that account for 30% of semen - Bulbourethral gland: produces secretion that neutralizes acid from urine Female Reproductive System - Ovaries, oviduct, uterus, vagina - Ovulation - egg released from ovary → float to fallopian tubes → travel through tubes (1 week) → fertilization → uterus → embryo implantation or menstruation → cervix → vagina Males - FSH enters testes → begin spermatogenesis - LH: enters testes → production & release of testosterone - Testosterone: spermatogenesis & secondary sexual characteristics Females - FSH: development of egg cells - LH: development of ova & stimulation of other hormones by ovaries - Estrogen: endometrial growth, ovulation, calcium absorption, & secondary sexual characteristics
Describe thermoregulation of endothermic & ectothermic animals
Metabolism produces heat: - Endotherms: conserve heat through insulation to maintain body temperature - Ectotherms: lack insulation and rely on heat from environment
Identify the components of prokaryotic cells
Metabolism: - Macronutrients: CHNOPS - Micronutrients: metallic animals Autotrophs (carbon from CO2) - Photoautotrophs - energy from Sun - Chemotrophs - energy from chemical compounds Heterotrophs (carbon from organic molecules) - Photoheterotrophs - light as energy source but obtain organic carbon made by other organisms - Chemoheterotroph - both carbon atoms and energy from organic molecules Role in Ecosystems (Carbon Cycle): - Producers: photosynthetic bacteria - Consumers: use organic compounds from producers and release CO2 to atmosphere - Decomposers: make organic molecules from dead organisms available Role in Ecosystems (Nitrogen Cycle - Nitrogen in the atmosphere (N2) is not usable by plants): - Nitrogen fixation: N2 to NH3(ammonia) - Ammonification: released during decomposition - Nitrification: ammonia converted to nitrate
Explain in what way smell & taste stimuli differ from other sensory stimuli & their interaction
Odors - Reception Odorants enter nose and dissolve in olfactory epithelium Order: 1. Receptors in olfactory bulb 2. Olfactory cortex 3. Frontal cortex 4. Thalamus Taste - Reception Gustation: sense of taste Taste buds: cluster of gustatory receptors Order: 1. Receptors in the tongue, esophagus, & palate 2. Medulla 3. Thalamus 4. Primary gustatory cortex
Discuss the similarities & differences between the two main groups of flowering plants (monocots & dicots)
Monocot: - parallel veins in leaves - single cotyledon - multiple fibrous roots - vascular and parenchyma tissues produced by the primary and secondary thickening meristems form the trunk - Produce Pollen: Monosulcate - Stem vascular tissue is scattered - Three or multiple of three Dicot: - branched veins - two cotyledons - flower parts come in four, five, or many whorls. - stem vascular tissue forms a ring pattern - herbaceous (not woody), - Produce Pollen: trisulcate or triporate - Tap root with many lateral roots
Discuss positive & negative feedback mechanisms used in homeostasis
Negative feedback loop - counteracts change from the set point: Food intake → increase glucose levels → pancreas releases insulin → glucose taken into cells → glucose levels decrease Positive feedback loop - maintains the direction of the stimulus: Ex: Blood clotting - clotting factor activates next factor in sequence until blood clot is formed
Identify the characteristics of phyla Cnidaria & Ctenophora
Phyla Cnidaria - Eumetazoa: radiata - Diploblastic: - Ectoderm: epidermis - Endoderm: lines digestive cavity - Special characteristic: Stinging cells contain nematocysts - Incomplete gut/ digestive system: Gastrovascular cavity One opening, serves as both mouth and anus - Primitive nervous system: Nerve net - Carnivorous - Reproduction: Asexual - budding Sexual - release gametes in water - Body Plans: Polyp - sessile (asexual reproduction) Medusa (sexual reproduction) Dimorphic - display both within life cycle: Polyp - asexual Medusa - sexual - Class: Anthozoa: corals, sea anemones; polypoid Scyphozoa: marine jellies; medusa Cubozoa: box jellyfish; true eyes Hydrozoa: both polyp and medusa forms Phyla Ctenophora (Comb Jelly) - Eumetazoa: radiata - Diploblastic - Lack cnidocytes - Complete gut
Identify the characteristics of phyla Porifera
Phyla Porifera - Simplest of all animals - Have ossicles: tiny skeletal "bones" that make up a true endoskeleton, or internal skeleton, covered by an epidermis. - Do not create a true gastrula during embryogenesis, and as a result do not produce a true endoderm or ectoderm - Aquatic - Symmetry: Asymmetric - Parazoans - No tissue, No organs - Lack digestive system, respiratory, circulatory system, lack reproductive organs, lack nervous system - Important Structures: (1) Osculum: opening for water expulsion, water entering the spongocoel is expelled via this large opening (2) Spongocoel: central cavity, water enters into the spongocoel through numerous pores, or ostia, that create openings in the body wall (3) Choanocytes: collar cells; directs water through the sponge to trap and ingest food via phagocytosis (4) Spicules: skeletal spikes of silica - Asexual - budding or fragmentation, Gemmules in freshwater sponges (produce a smaller sponge that can fall off and grow) - Sexual - differentiation of amoebas (monoecious / hermaphroditic) Sponge Characteristics: - Sponge larvae - flagellated, able to swim - Adult Sponge - sessile (do not move), spend their life attached to a substratum - Various canals, chambers, and cavities facilitate exchange of water and nutrients throughout the sponge (water is vital to sponges for feeding, excretion, and gas exchange, their body structure facilitates the movement of water through the sponge)
Identify the characteristics of phyla Nematoda, Tardigrada, & Arthropoda
Phylum Nematoda - Pseudocoelomates - Complete digestive system - Not segmented - Some cephalization: cluster of neurons - Lack true circulatory system - Cuticle: collagen, chitin - Complex life cycle - Many are parasitic Phylum Tardigrada - Slow steppers, water bears - Partial coelom Hemocoel: blood coelom (Functions as circulatory system due to small size) True coelom - near gonads - Cuticle: chitin - Cryptobiosis - Segmented - Cephalization: cluster of neurons - Resilient to environmental pressures Phylum Arthropoda - Jointed appendages - Exoskeleton - made of chitin - Segmented body - Respiration: gills (found in crustaceans), trachea (found in insects) - Coelomate - hemocoel - Subphylum Organisms: Chelicerata: spiders, horseshoe crabs Myriapoda: Chilopods (centipedes, 1 set of legs per segment, carnivores), Diplopoda (millipede, 2 sets of legs per segment, herbivores) - Crustacea: (crabs, lobsters, crayfish, isopods, barnacles, and some zooplankton) - Hexapod: (insects and their six-legged relatives)
Describe the key features of the phyla Platyhelminthes & Mollusca
Phylum Platyhelminthes (Flatworms) - Acoelomate - have gastrovascular cavity - Monecious - Open circulatory system - Beginning of cephalization? - Flame cells - primitive excretory system - Some are free-living, some parasitic - Class: Turbellaria - planaria Trematoda - flukes Cestoda - tapeworms Phylum Mollusca: - Predominantly marine - Coelomate - Body plan Mantle: secretes shell Muscular Foot: Visceral Mass: holds organs - Primary gills for respiration - Complete digestive system - Open circulatory system (Cephalopods - Closed circulatory system) - Classes: Polyplacophora - Many plates - Unique Feature: have radula → to scrape algae off rocks Gastropoda - snails, slugs, nudibranchs - Can have lungs - Head region Bivalvia - clams, oysters, scallops Cephalopoda - Most complex - Have closed circulatory system - Complete digestive system - Open circulatory system - Hemocoel - No blood cavity
Compare & contrast plant & animal hormones
Plant Hormones: A plant's sensory response to external stimuli relies on hormones - Flowering - Fruit setting - Maturation Plant hormones can be produced in any cell, can act at their place of origin or be transported to other cells and often work either synergistically or antagonistically with other hormones (1) Auxins: main hormone responsible for cell elongation in phototropism and gravitropism; controls differentiation of meristem into vascular tissue, promotes leaf development and arrangement (2) Cytokinins: promotes cell division (3) Gibberellins: stimulate shoot elongation, seed germination, and fruit/ flowermaturation (4) Abscisic acid: response to stress; counters many effects of GAs and auxins (5) Ethylene: fruit ripening, flower wilting, and leaf fall Animal Hormones: Animal hormones are produced in specific glands, transported to a differentsite and work alone
Distinguish between hybrid inviability & sterility
Postzygotic barriers - Hybrid inviability: an embryo is produced, but cannot survive development - Hybrid sterility: different species can produce a viable offspring, but that offspring cannot reproduce
Compare & contrast the embryonic development of protostomes & deuterostomes
Protostomes: mouth first - Spiral cleavage - Determinate cleavage: fate of cells is determined early in development - Schizocoel: clumps form and break away - Protostomes include arthropods, mollusks, and annelids Deuterostomes: mouth second - Radical cleavage - Indeterminate cleavage: fate of cells in determined later in development - Enterocoel: pinches off - Includes more complex animals such as chordates, but also some "simple" animals such as echinoderms
Describe the characteristics of ray-finned & lobe-finned fishes
Ray-finned Fish - Class Actinopterygii - ½ of all vertebrates Lobe-finned Fish - Class Sarcopterygii - Gave rise to tetrapod - Includes: Lungfish, coelacanths
Describe the three steps in sensory perception (sensation)
Sensory Transduction: conversion of stimuli to an electric signal in the nervous system - Sensory receptor receives stimulus → activates neuron → info relayed to CNS (1) Reception: activation of sensory receptors by stimulus - Sensory receptors are specific: touch, light, sound - Receptive field: the region in space in which a sensory receptor can respond to a stimulus (2) Transduction: translation of sensory signal to an electrical signal - Disturbance of dendrites on receptor opens gated ion channels → depolarization - Information included in signal (3) Perception: interpretation of the sensation at higher levels in the nervous system - Thalamus receives all sensory signals except olfactory; clearinghouse and relay station
Describe & provide examples of sexual selection, intrasexual selection, & intersexual selection
Sexual selection: Some trait influences an individual's chance of mating - Handicap principle - selection for traits that are detrimental to the individual's survival but increase mating frequency - Good genes hypothesis - ornaments are a signal of genetic superiority EX: Intrasexual selection (Mate Competition): one sex competes for access to the other sex, the other sex always chooses the winner EX: Intersexual selection (Mate Choice): one sex chooses mate based on characteristics of other sex EX:
Identify characteristics that fungi share with plants, animals, & bacteria
Shared characteristics with plants: Cell wall, Immobile Shared characteristics with bacteria: Decomposers, Absorb nutrients across the cell surface Shared characteristics with animals: Heterotrophic, Chitin in cell walls similar to exoskeleton of arthropods, Melanin pigment, Store carbohydrates as glycogen
Identify different types of fruits & how they are formed
Simple fruits: derived from a single ovary - Berries - where the two inner most tissues are fleshy and usually contain many seeds EX: Pea fruit, Blueberries, Cranberries, Grapes, Tomatoes, Passion fruit - Drupes - endocarp forms a hard enclosure (pit) surrounding the seed EX: Mangos, Olives, Pistachios Aggregate fruits: form from many carpels that fuse together EX: Raspberry fruit Multiple fruits: form from a cluster of flowers called an inflorescence EX: Pineapple fruit Accessory fruits: are formed from apart of the plant other than the ovary EX: Apple fruit
Describe the life cycle of a fern
The dominant stage of the life cycle of a fern is the sporophyte, which consists of large compound leaves called fronds (diploid) Zygote → mitosis → sporophyte → sporangia →meiosis → spores → Germination → Gametophyte (Mitosis) → sporophyte Antheridium → sperm Archegonium → egg
Explain the endosymbiotic theory
The first eukaryote may have originated from an ancestral prokaryote that had undergone membrane proliferation, compartmentalization of cellular function (into a nucleus, lysosomes, and an endoplasmic reticulum), and the establishment of endosymbiotic relationships with an aerobic prokaryote, and, in some cases, a photosynthetic prokaryote, to form mitochondria and chloroplasts, respectively 1. Start with two independent bacteria 2. One bacterium engulfs the other 3. One bacterium now lives inside the other 4. Both bacteria benefit from the arrangement 5. The internal bacteria are passed on from generation to generation
Describe the alternation of generations life cycle
They have multicellular diploid and haploid life stages that are apparent to different degrees depending on the group. - Apical meristem tissue in roots and shoots - Waxy cuticle - Lignin
Define viroids & their targets of infection
Viroids = small circles of DNA - Only known to infect plants - Can replicate within cells - Do not manufacture any proteins - Can cause crop failures