Final Exam Review PDF

Final Exam Review GOOD LUCK! Chapter 22 What is Lamarck’s Hypothesis of evolution? Jean-Baptiste de Lamarck (1744–1829) proposed two principles to explain evolutionary change. ○ Use and disuse: body parts used extensively become larger and s...

Final Exam Review GOOD LUCK! Chapter 22 What is Lamarck’s Hypothesis of evolution? Jean-Baptiste de Lamarck (1744–1829) proposed two principles to explain evolutionary change. ○ Use and disuse: body parts used extensively become larger and stronger, unused parts deteriorate. ○ Inheritance of acquired characteristics: modifications acquired in one’s lifetime can be passed to offspring. ○ This mechanism is not supported by experimental evidence. What is natural selection? Darwin developed two main ideas: ○ Descent with modification: new species originates from ancestral forms. ○ Natural selection: a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than do other individuals because of those traits. Know the examples of natural selection. What were Darwin’s observations and inferences? a) Dead-leaf moth (Oxytenis modesta) in Peru. b) Buff end moth (Phalera bucephala) in Scotland. Darwin drew two inferences from two observations: ○ Observation #1: Members of a population often vary in their inherited traits.  ○ Observation #2: All species can produce more offspring than the environment can support, and many of these offspring fail to survive and reproduce. ○ Inference #1: Individuals with inherited traits that increase survival and reproduction in an environment tend to produce more offspring than other individuals. ○ Inference #2: The unequal ability of individuals to survive and reproduce will lead to the accumulation of favorable traits in the population over generations. Difference between homology and analogy? Homology - is similarity resulting from common ancestry. ○ Homologous Structures - are structures found in different organisms that have the same skeletal structure but exhibit different functions. Convergent evolution - is the evolution of similar, or analogous, features in distantly related groups. Analogous traits arise not through common ancestry, but through independent adaptation to similar environments Chapter 23 What does p & q stand for in the Hardy Weinberg Equation? Hardy-Weinberg Equilibrium - describes the constant frequency of alleles in such a gene pool. If p and q represent the relative frequencies of the only two possible alleles in a population at a particular locus. ○ p2 + 2pq + q2 = 1 ○ p2 and q2: frequencies of the homozygous genotypes. ○ 2pq: frequency of the heterozygous genotype. Use the Hardy Weinberg equation to find the carriers of particular genetic disorders. We can assume the locus that causes phenylketonuria (PKU) is in Hardy-Weinberg equilibrium given that: ○ The PKU gene mutation rate is low. ○ Mate selection is random with respect to whether or not an individual is a carrier for the PKU allele. ○ Natural selection can only act on rare homozygous individuals who do not follow dietary restrictions. ○ The population is large. ○ Migration has no effect as many other populations have similar allele frequencies. The occurrence of PKU is 1 per 10,000 births: q2 = 0.0001 q = 0.01. ○ The frequency of normal alleles is: p = 1 – q = 1 – 0.01 = 0.99. ○ The frequency of carriers is: 2pq = 2 x 0.99 x 0.01 = 0.0198. or approximately 2% of the U.S. population. What are microevolution, genetic drift, founder effect and bottleneck? Microevolution - the change in allele frequencies in a population over generations, is evolution at its smallest scale. THREE mechanisms cause allele frequency change: ○ Natural Selection: (adaptation to the environment). ○ Genetic Drift: (chance events alter allele frequencies). ○ Gene Flow: (transfer of alleles between populations). Founder Effect - occurs when a few individuals become isolated from a larger population and establish or found a colony. ○ Allele frequencies in the small founder population can be different from those in the larger parent population. For example, genetic drift could occur if a few individuals are indiscriminately blown to a new island by a storm. Bottleneck Effect - is a sudden reduction in population size due to a change in the environment. ○ Depletion of food supply or an outbreak of disease. ○ The resulting gene pool may no longer be reflective of the original population’s gene pool. ○ Understanding the bottleneck effect can increase understanding of how human activity affects other species. Chapter 24 What is the concept of biological species concept? Biological Species Concept - states that a species is a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring; they do not breed successfully with other populations. What are the prezygotic and postzygotic methods of reproductive isolation? Prezygotic barriers block fertilization from occurring by: ○ Preventing different species from attempting to mate. ○ Preventing the successful completion of mating. ○ Hindering fertilization if mating is successful. Habitat Isolation - species may occupy different habitats, and never come in contact with each other. Temporal Isolation - species have different mating times of the day or season. Behavioral Isolation - some species require unique signals for successful mating. Mechanical Isolation - anatomical differences in reproductive organs may interfere with successful mating. Gametic Isolation - sperm of one species may not be able to fertilize eggs of another species. Postzygotic barriers prevent the hybrid zygote from developing into a viable, fertile adult: ○ Reduced hybrid viability - genes of the different parent species may interact and impair the hybrid’s development. ○ Reduced hybrid fertility - even if hybrids are viable, they may be sterile. ○ Hybrid breakdown - first-generation hybrids are viable and fertile, but when they mate with another species or with either parent species, offspring of the next generation are feeble and sterile. What is allopatric and sympatric speciation? Allopatric Speciation - gene flow is interrupted or reduced when a population is divided into geographically isolated subpopulations. Sympatric Speciation - takes place in populations that live in the same geographic area. Chapter 25 What is a protobiont/protocell?  Replication and metabolism are key properties of life and may have appeared together. Protocells may have been fluid-filled vesicles with a membrane-like structure. In water, lipids and other organic molecules can spontaneously form vesicles with a lipid bilayer. What gas was most abundant in earth’s early atmosphere? Before cyanobacteria, the atmosphere was mostly CO2 from volcanic eruptions. Cyanobacteria - the source of oxygen was likely bacteria similar. ○ Most atmospheric oxygen (O2) is of biological origin. ○ O2 produced by oxygenic photosynthesis reacted with dissolved iron and precipitated out to form banded iron formations. Why is DNA the genetic material? Greater stability and stored genetic information. In fossil dating, know the definition of "half-life", and be able to calculate the age of a fossil, given a radioisotope and its half-life in years. The order of fossils in rock strata tells us the sequence in which they were formed. The ages of fossils can be determined by radiometric dating, which is based on the decay of the radioactive isotope. A “parent” isotope decays to a “daughter” isotope at a constant rate. Each isotope has a known half-life, the time required for half or 50% the parent isotope to decay. What the serial endosymbiotic theory is - how does this explain the origin of mitochondria and chloroplasts? Serial endosymbiosis supposes that mitochondria evolved before plastids through a sequence of endosymbiotic events. Chapter 26 Know the importance of phylogenetic trees. Phylogeny - is the evolutionary history of a species or group of related species. Systematics - is a discipline focused on classifying organisms and determining their evolutionary relationships. Systematists use fossil, molecular, and genetic data to infer evolutionary relationships. Know how to find the common ancestor of phylogenetic trees. Define Clade, Monophyletic, Paraphyletic, and Polyphyletic. Clade - is a group of species that includes an ancestral species and all its descendants. ○ Clades can be nested in larger clades, but not all groupings of organisms qualify as clades. Monophyletic - (single tribe) consists of the ancestral species and all its descendants. Paraphyletic - (besides the tribe) consists of an ancestral species and some but not all of its descendants. Polyphyletic - (besides the tribe) consist of various species with different ancestors. Know the modern classification system (domain-kingdom-phylum…….) Linnaeus introduced a system for grouping species in increasingly broad categories. The taxonomic groups from broad to narrow are domain, kingdom, phylum, class, order, family, genus, and species. (Don’t kick pink cats or father gets sad) NICE!!! lol  A taxonomic unit at any level of hierarchy is called a taxon Chapter 27 Bacteria and Archaea Difference between gram positive and gram negative bacteria Gram Positive Bacteria: ○ Stains VIOLET with the dye. ○ THICCC layer of peptidoglycan. ○ No outer membrane… less protection. ○ FEWER species cause diseases. ○ More SENSITIVE to antibiotics. Gram Negative Bacteria:  ○ Stains RED with the dye. ○ THIN layer of peptidoglycan. ○ Membrane outside the cell wall… protects from immune attack. Contains lipopolysaccharide (LPS)... releases toxins. ○ MOST cause diseases. ○ More RESISTANT to antibiotics. Composition of the cell wall. Choice of antibiotics for gram positive and gram negative bacteria. Gram negative tends to be more RESISTANT to antibiotics than gram positive. Gram positive choice of antibiotic is PENICILLIN. What are plasmids? A genetic structure in a cell that can replicate independently of the chromosome. Know the different nutritional modes in prokaryotes: Autotrophs, Heterotrophs, Aerobic, Anaerobic. Photoautotrophs - uses light energy and CO2 to synthesize organic molecules. ○ Ex. Cyanobacteria, algae, plants. Chemoautotrophs - use energy from chemical reactions and CO2 to make organic molecules. ○ Ex. Sulpholobus, nitromonas. Photoheterotrophs - uses light to generate energy and carbon from organic molecules. ○ Ex. Rhodobacter, Chloroflexus Chemoheterotroph - breakdown organic molecules to make ATP. ○ Ex. Clostridium Obligate aerobes - require oxygen for cellular respiration. ○ Ex. Bacillus Facultative anaerobes - can survive with or without oxygen. Cellular respiration if oxygen is present and fermentation in the absence of oxygen. ○ Ex. Staphylococcus Obligate anaerobe - are poisoned by oxygen, carry out only fermentation. ○ Ex. Micrococcus, nocardia. Mechanism of genetic variation in bacteria-transformation, transduction and conjugation. Five groups of Bacteria Proteobacteria - causes cholera and gonorrhea (helicobacter); possible source of eukaryotic mitochondria  Chlamydias - parasites; have no peptidoglycan; cause chlamydia Spirochetes - spiral through; cause syphilis and lyme disease Cyanobacteria - only prokaryote with plant-like photosynthesis Gram Positive Bacteria - tuberculosis; anthrax; botulism; staphylococcus aureus Characteristics of Archaea, extremophiles, thermophiles and methanogen Archaea: ○ NO nuclear envelope ○ NO membrane-enclosed organelles ○ NO peptidoglycan in the cell wall Extremophiles - live in extreme conditions and environments. Thermophiles - thrive in hot environments. Methanogen - lives in swamps and marshes that produce methane. What is the most important ecological role played by the prokaryotes? Recycle of chemical elements between living and nonliving components of the environment. Chapter 28 Protists Which organisms are thought to be the ancestors of the green plants? Charophytes What are the five major groups of Protists and their clades? Chrysophytes Dinoflagellates Euglenoids Slime Molds Protozoans Important characteristics of Diplomonads, Parabasalids, Euglenozoans, Aveolates, Stramenopila, Amoebozoa Four Supergroups: Excavata: some have an excavated groove on one side of the cell body. Reduced mitochondria (no electron transport chain so no cellular respiration, also no plastids) ○ Diplomonads: Have modified mitochondria called MITOSOMES. Derive energy anaerobically by glycolysis. Have two equal-sized nuclei and multiple flagella. Are often parasites. Ex: Giardia instestinalis. ○ Parabasalids: Hydrogenosomes release h2 gas  trichomonas vaginalis ○ Euglenozoans: SPIRAL or CRYSTALLINE ROD of unknown function inside their FLAGELLA. Euglenids with the eyespot and pocket for flagella Kinetoplastids: mitochondria with mass of DNA called kinetoplast; sleeping sickness (trypanosomes) & chagas disease ○ Trypanosomes keep changing their surface proteins, which helps them evade antibodies. SAR: ○ Stramenopiles: Heterotrophs as well as certain groups of algae. Have a “HAIRY” and “SMOOTH” flagella. Diatoms: photosynthetic algae that has glass cell walls; pump CO2 to the ocean floor since they break down slowly after death. Brown algae: giant seaweed;kelp; largest and most complex species of algae; contain pigment fucoxanthin They have holdfast (root), stipe (stem) & blade (leaf) Don’t have true tissue or organs like plants Make zoospores that can swim using flagella Oomycetes: water mold; decomposers; ruined potatoes & oaks ○ Alveolates: Have membrane-bounded sacs (ALVEOLI) just under the plasma membrane. Dinoflagellates (Flagellates): two flagella; red tidal blooms; toxic to fish; live inside corals and provide food for them. Apicomplexans (Parasites): infectious cells called sporozoite; apex to pierce cells; Plasmodium, causes malaria. Ciliates (Cilia): use cilia to move/feed; paramecium with micronucleus, macronucleus and oral groove ○ Rhizarians: amoeba with thread-like pseudopodia Archaeplastida: ○ Red Algae: contains phycoerythrin and live the deepest in water; reproduce sexually but gametes don’t have flagella ○ Green Algae: Chlorophytes: chlamydomonas (unicellular) Charophytes Plants (closest ancestor is charophytes)  Unikonta: ○ Amoebozoans: lobe/tube shaped pseudopodia; entamoeba & slime mold ○ Opisthokonts: flagella located in the posterior Nucleariids (amoeba that feeds on algae or bacteria) and fungi (sister taxa) Choanoflagellates and animals (sister taxa) CHAPTER 31 Fungi What is a fungus? What is a mycelium? What is hyphae? What are Exoenzymes? Fungi - are HETEROTROPHS that absorb nutrients. Uses hydrolytic enzymes (EXOENZYMES) to break down complex molecules into small organic molecules. ○ Mycelium - networks of branched (HYPHAE) adapted absorptions. ○ Hyphae - each of the branching filaments that make up the mycelium of fungus. Decomposers are also called saprophytes What is septate or coenocytic hyphae? Septate Hyphae - divided into cells by SEPTA, with pores allowing cell-to-cell movement of organelles. Coenocytic Hyphae - LACK septa and have continuous cytoplasmic mass with hundreds or thousands of nuclei. Why are mycorrhizae important? Mycorrhizae (FUNGUS ROOTS) - they provided PHOSPHATE IONS and minerals to plants. Most vascular plants have mycorrhizae. How is ectomycorrhizae different from arbuscular mycorrhizae? Ectomycorrhizae - forms sheaths of hyphae over a root and also grows into the extracellular spaces of the root cortex. Arbuscular - extends hyphae through the cell walls of root cells and into tubes formed by invagination of root cell membrane. Define: Plasmogamy, Karyogamy, Mycorrhizae Plasmogamy - fusion of CELLS or CYTOPLASM between 2 mycelia. Karyogamy - fusion of the NUCLEI (hours or days or even centuries may pass before karyogamy). Mycorrhizae (FUNGUS ROOTS) - that provide phosphate ions and minerals to plants. Know the general Life cycle of fungi. On what basis are fungi classified and the important characteristics of Chytrid, Zygomycota, Glomeromycetes, Ascomycetes, Basidiomycetes. Chytrids (Batrachochytrium dendrobatidis): might be the cause of the recent decline in amphibians worldwide. Have flagellated spores. Decomposers and parasites; flagellated spores (zoospores) Zygomycota: ○ Ex. BLACK BREAD MOLD. ○ Named for their sexually produced ZYGOSPORANGIA (heterokaryotic) that houses and protects the zygote. ○ Coenocytic hyphae. Glomeromycetes: ○ Phylum MUCOROMYCOTA also includes an ARBUSCULAR forming clade of fungi. Ascomycetes (SAC FUNGI): ○ Produce sexual spores in saclike ASCI contained in fruiting bodies called ASCOCARP ○ Ascocarp contain spore-forming asci. ○ NEUROSPORA is a model organism with a well-studied genome. Basidiomycetes (CLUB FUNGI): ○ Ex. Mushrooms, puffballs, shelf fungi. ○ Phylum named for the BASIDIUM, a cell in which karyogamy and meiosis occur. ○ Decomposers of wood. What fungi are classified under deuteromycetes? Deuteromycetes are fungi with no known sexual stage. Examples of symbiotic relationship of fungi with other organisms. Fungi form mutualistic relationships with plants, algae, cyanobacteria, and animals, where they absorb nutrients from the host organism and reciprocate with actions that benefit the host. CHAPTER 29, CHAPTER 30 Plants What are the characteristics shared by land plants and charophyceans? Walls toughened by sporopollenin (protects against harsh environmental conditions) Multicellular, dependent embryos (provide nutrients and protection to the developing embryo) Cuticle (reduces water loss) Stomata (control gas exchange and reduce water loss) What are the characteristics that are unique to land plants but absent in Charophyceans? All land plants show alternation of generations in which two multicellular body forms alternate. What is a gametophyte? What is a sporophyte? Gametophyte - is a haploid and produces haploid gametes by MITOSIS. Sporophyte - is a diploid that produces haploid spores by MEIOSIS. Specific gametophyte and sporophyte differences as the plants evolved from mosses to ferns, to gymnosperms, then to angiosperms. Which feature would definitively identify organisms as land plants? Walls toughened by sporopollenin: Protects against harsh environmental conditions Multicellular, dependent embryos: Provide nutrients and protection to the developing embryo Cuticle: Reduces water loss Stomata: Control gas exchange and reduce water loss Definition of and the stages of alternation of generations. Alternation of Generation - life cycle found in plants and some algae. Consist of two distinct multicellular organisms: GAMETOPHYTE and SPOROPHYTE. Stages of Alternation of Generation: ○ Gametophyte produces haploid gametes by mitosis ○ Two gametes unite (fertilization) and form a diploid zygote ○ Zygote develops into a multicellular diploid sporophyte by mitosis ○ Sporophyte produces unicellular haploid spores by meiosis ○ Haploid spores develop into a new multicellular gametophyte, and the cycle begins again What is antheridia? What is archegonia? Antheridia - structures that produce and RELEASE SPERM CELLS. Archegonia - structures that produce and CONTAIN EGG CELLS. What is the difference between gametangia and sporangia? Gametangia - structures that produce and enclose gametes (reproductive cells) in plants. Sporangia - structures that produce and enclose spores in plants. Which stage is dominant in the mosses, the ferns, seed bearing plants and the flowering plants - the sporophyte or the gametophyte? Moss - dominated by gametophytes. Fern - dominated by sporophyte. Seed bearing plants - reduced gametophyte and dominant sporophyte. How are plants classified? They are classified based on their life cycle and reproductive structures. What are the major groups of plants? Nonvascular (bryophytes): ○ Liverworts ○ Mosses ○ Hornworts Vascular: ○ Seedless Vascular Lycophytes - club mosses, spikemosses, quillworts. Monilophytes - ferns, horsetail, and whisk ferns. ○ Seed Plants Angiosperms - flowering plants & the seeds grow inside chambers. Gymnosperms - “naked seed” What are Embryophytes - what is important about them? Embryophytes - also known as land plants, are a significant group in the evolution of plants. Developed multicellular gametangia, which are structures for producing gametes, marking a crucial step in the evolution of plant reproduction on land. What characteristics do all vascular plants share? Life cycles with dominant sporophytes: Unlike nonvascular plants, vascular plants have a dominant sporophyte generation that is larger and more complex than the gametophyte generation. Transport in vascular tissues: Vascular plants have specialized tissues called xylem and phloem that transport water, minerals, and sugars throughout the plant. Well-developed roots and leaves: Vascular plants have roots that anchor them to the ground and absorb water and nutrients, and leaves that are adapted for photosynthesis. Spore-bearing leaves called sporophylls: Vascular plants have specialized leaves called sporophylls that bear spores for reproduction. Difference between homosporous and heterosporous. Homosporous plants - produce only one type of spore, which gives rise to a bisexual gametophyte. Heterosporous plants - produce two types of spores: megaspores and microspores Characteristics of seed bearing plants. Seed Bearing Plants - a group of plants that produce seeds as part of their reproductive process. They are divided into two main groups: gymnosperms and angiosperms. What is megasporangium and microsporangium? Megasporangium - structure that produces megaspores, which develop into FEMALE gametophytes. Microsporangium - structure that produces microspores, which develop into MALE gametophytes. What is double fertilization, and why is it important to the plant? Double Fertilization - This occurs after the two sperm reach the female gametophyte. One sperm fertilizes the egg, forming the zygote, while the other sperm combines with the two polar nuclei, forming a triploid nucleus in the central cell of the female gametophyte.  Importance - ensures that endosperm develops only in ovules where the egg has been fertilized, preventing the wastage of nutrients on infertile ovules. Difference between monocots and dicots Monocot - species with one cotyledon. ○ About one-quarter of angiosperm species are monocots, or roughly 70,000 species. ○ Some of the largest groups are the orchids, grasses, and palms. ○ Most monocots have parallel major veins of equal diameter that run the length of the blade. Dicot - species with two cotyledons. ○ More than two-thirds of angiosperm species are dicots, or roughly 170,000 species. ○ The largest group is the legume family, which includes such crops as peas and beans. ○ Most of the familiar flowering trees are dicots, such as oak, walnut, maple, willow, and birch. ○ Eudicots generally have a branched network of veins arising from a major vein (the midrib) that runs down the center of the blade. Chapter 32 Know the characteristics of all animals. Kingdom Animalia Characteristics: ○ Multicellular Eukaryotes ○ Lack cell wall ○ Heterotrophs: they obtain food by ingestion ○ Two types of cells for conduction Muscle and nerve cells ○ Supported by structural protein: Collagen ○ Most carry out Sexual Reproduction. Know the stages in embryonic development and germ layers. Cleavage - a succession of mitotic cell divisions without cell growth between divisions. Blastula - a hollow ball of cells that surrounds a cavity called blastocoel. Gastrulation - a process in which one end of the embryo folds inward, expands and fills the blastocoel (cavity of blastula) with layers of embryonic tissues called ectoderm (outer layer) and endoderm (inner layer). Archenteron - the pouch that was formed by gastrulation and opens to outside via blastopore. During the embryonic development, there are THREE GERM LAYERS that are given to tissues and organs to animals. 1. Ectoderm - outer layer of the embryo. 2. Mesoderm - which gives muscles and organs that's between the digestive tube and outer covering. 3. Endoderm - inner layer of the embryo. Differences between protostome and deuterostome animals? The difference between protostome and deuterostome animals are their cleavage, coelom formation and fate of blastopore.  ○ What are Diploblastic & Triploblastic animals? Diploblastic - radially symmetric animals that have TWO germ layers. ○ Endoderm and ectoderm Triploblastic - bilaterian symmetric animals that have THREE germ layers. ○ Endoderm, mesoderm, and ectoderm. What are the general differences between coelomate, pseudocoelomate & acoelomate animals? Coelomate and pseudocoelomate have a body cavity derived from mesoderm. Whereas, acoelomates do not. ○ Coelomates - have a body cavity (coelom) lined with tissue from mesoderm. Ex: Annelids ○ Pseudocoelomates - have a body cavity derived from mesoderm AND endoderm. Ex: Nematodes ○ Acoelomates - triploblastic organisms that DOES NOT have a body cavity. Ex: Flatworms. Know the unique features of Palezoic, Mesozoic and Cenozoic eras. What is the Cambrian explosion and what are its causes? Paleozoic Era (542 - 241 Million Years Ago): ○ When the Cambrian Explosion happened. First large animal fossil with a hard mineralized skeleton. Most fossils from the Cambrian Explosion were bilaterians. Mesozoic Era (251 - 65.5 Million Years Ago): ○ DINOSAURS RULED THE WORLD ○ First Coral Reefs emerged in the ocean. ○ First mammals emerged. ○ Flowering insects and plants diversified. ○ Vertebrates made the transition to land around 360 million years ago. Cenozoic Era (65.5 Million Years Ago - Present) ○ Extinction of non flying dinosaurs and marine reptiles ○ Modern mammal orders and insects, flowering plants diversified. ○ Global climate has cooled. What are Hox genes? Role in development of animal embryos. Regulate expression of other genes. Most animals share a unique family of regulatory genes. Control cell division and differentiation - producing morphological features. What is radial/ bilateral symmetry and examples of animals that have it? Radial Symmetry - animals that have NO front, back, left and right side. ○ Ex: Octopus and squids. Bilateral Symmetry - animals that have a front, back, left and right side. ○ Ex: Crawfish and cat. Characteristics of Ecdysozoans. Ecdysozoan - they shed their exoskeleton through a process called Ecdysis. ○ Ex: Nematodes and Arthropods. Chapter 33 Invertebrates: ○ Animals that lack backbone. ○ Account for 95% of species. Characteristics of Sponges, function of choanocytes, amoebocytes… Sponges - LACK TRUE TISSUE. ○ Phylum Porifera. ○ Freshwater and marine, suspension feeders capturing particles suspended in water. ○ Sessile - mistaken for plants. ○ Body like sac… simple, asymmetrical, no tissue. ○ Produce sexually and asexually. ○ Hermaphrodites - function as male and female. Function of Choanocytes and Amoebocytes: ○ Choanocytes - flagellated “collar cells” that generate water currents through the sponge and ingest suspended food through phagocytosis. Phagocytosis - ingestion of bacteria. ○ Amoebocytes - they take food from surrounding areas and from choanocytes, digest it and carry out nutrients to other cells. What organisms belong to the clade Eumetazoa? Eumetazoa - animals with TRUE tissue. ○ Phylum: Cnidaria. Ex: Jellyfish, hydra, sea anemone, coral reefs and clown fish. Cnidaria: body forms, what are cnidocytes, nemotocysts and what is their function? Cnidaria: ○ Diploblastic - two germ layers. ○ Radial Symmetry ○ Gastrovascular Cavity - sac like digestive system.  ○ Single opening at the top (mouth/anus) ○ Two types of body form: Polyp: cylindrical form and attached to substrate. Ex: Hydra and sea anemone. Medusa: flat body and moves freely. Ex: Jellyfish. Cnidocytes - unique cells of tentacles for defense and prey capture. Nematocysts - specialized organelles within cnidocytes that eject a stinging thread. Know the Acoelomates. Platyhelminthes examples. Flat worn, Blood fluke with 2 hosts Acoelomates - no true body cavity. ○ Porifera (sponges) ○ Cnidaria (sea anemone and jellyfish) ○ Platyhelminthes (flatworms) Flatworms are divided into TWO lineages: Catenulida or “chain worms”, reproduce asexually by budding. Rhabditophora are more diverse that include both free-living and parasitic species. 1. Free-living Species: Marine flatworms. Commonly called Planarians. 2. Parasitic Species: important groups are trematodes and tapeworms. Trematoda - causes schistosomiasis in humans. ○ Ex: Blood Flukes Sexual Reproduction in humans. Asexual Reproduction in snails. Tapeworms - parasitic vertebrates that lack a digestive system.  ○ Absorb nutrients from the host's intestines. That is how humans acquire larvae by eating undercooked meat. ○ They mature in human intestines. Know the pseudocoelomates: What characteristics do Rotifers have? What is parthenogenesis? Bilateria: Pseudocoelomates. ○ Phylum Rotifera - wheel bearer. Have a crown of cilia that pushes water into the mouth. Complete digestive system and other organs. Pseudocoelom, filled with fluid, functions as a hydrostatic skeleton. Reproduced by parthenogenesis. Which females produce offspring from unfertilized eggs reproduce without males. ○ Phylum Nematoda - infect plants by attacking the roots. Humans could acquire this by eating undercooked and raw meats. They will develop a disease called Trichinosis. Ex: Roundworms, hookworm, pinworms. Found in aquatic habitat. Cylindrical bodies, nonsegmented, covered by a tough coat called cuticle. Carries out ecdysis or molting Know the coelomates: What are the characteristics of Molluscs:Ex. ? Shell? Body parts? Bilateria: Coelomates. 1. Phylum Mollusca: Ex: clams, snails, slugs, squids, oysters and octopus. Reduced head. Soft body, hard shell made of calcium carbonate. Many molluscs have a water filled mantle cavity and feed using a rasplike radula. Molluscs Body Parts - THREE main parts. Large muscular foot - for movement. Visceral Mass - contains organs. Mantle - tissue covering the organs and secretes shell. There are FOUR major class of molluscs: Polyplacophora (chitons) ○ Oval-shaped marine animals with a shell composed of eight dorsal plates. ○ Unsegmented body.  Gastropoda (snails and slugs) ○ About three-quarters of all living species of molluscs are gastropods. Bivalvia (clams, oysters, mussels and scallops) ○ Have a shell divided into two halves, that has eyes and sensory tentacles. Cephalopoda (squids, octopuses, cuttlefish and chambered nautilus) ○ Octopus Creeps along the sea floor in search of prey. ○ Squids  To fire a jet of water, which allows them to swim very quickly. ○ Shelled cephalopods called ammonites were common but went extinct at the end of the Cretaceous Era. They look like shrimp with a hard shell. 2. Phylum Annelida: Ex: earthworms and leech. Segmented worms found in sea, freshwater or damp soil. Body parts: series of fused rings. Divided into THREE clades: Polychaeta (many long hair) Oligochaeta (earthworms) are named for sparse chaetae, long hair or bristles made of chitin. Hirudinea (leeches). ○ Earthworms: Eats through soil for nutrients. They are hermaphrodites but cross-fertilize. Some reproduce asexually by fragmentation. ○ Leeches: Blood-sucking parasites. Secretes an anesthetic. Secretes anticoagulant hirudin - prevents blood clotting.  3. Phylum Arthropoda Ex: insects, crabs and lobsters. THREE key characteristics: Segmented body. Hard exoskeleton. Jointed appendages. Living arthropods consist of THREE major lineages: Chelicerates (sea spiders, horseshoe crabs, scorpions, ticks and spiders.) Myriapods (centipedes and millipedes). Pancrustacean (insects, lobsters, shrimp, and barnacle). Define metamorphosis Metamorphosis - stage development of insects. There are TWO kinds: ○ Complete Metamorphosis - insects that has a larval stage such as maggot and caterpillars. The larval stage looks completely different from the adult stage. Egg → Larva → Pupa → Adult. ○ Incomplete Metamorphosis - insects that start young (nymphs) resemble the adults but look smaller, different body proportions and lack wings. What are the general characteristics of the body plan of insects? Chapter 34 What are the basic characteristics shown by chordates? Notochord - flexible rod that supports the body. Dorsal Hollow Nerve Cord - develops into brain and spinal cord. Pharyngeal Sit or Pharyngeal Clefts - functions for feeding… gills. Muscular Post Anal Tail - helps with propel through water. Subphyla of chordate. Cephalochordata: ○ Ex: Lancelets - “blade like” that resembles chordates. Urochordata: ○ Ex: Tunicates - early diverging chordate group, but only display key features at larvae stage. Vertebrata What is the order of evolution of chordates from the ancestral chordate? Research suggests that ancestral chordates looked like lancelets. ○ Anterior with mouth → Notochord → Dorsal Hollow Nerve Cord → Pharyngeal Slit → Post-Anal Tail. What are the characteristics of vertebrates, Amphibians, reptiles, birds, mammals, primates? Vertebrates - had skull, backbone, well defined head with a brain and sensory organs. Fossils representing vertebrates formed during the Cambrian explosion. TWO Clades: ○ Cyclostomes - JAWLESS vertebrates. Myxini (Hagfish) Petromyzontida (Lampreys). ○ Gnathostomes - JAW vertebrates. Chondrichthyans (Sharks, stingrays) Shark embryos can develop differently. Oviparous: eggs hatch OUTSIDE mother’s body. Ovoviviparous: eggs retain within the oviduct. Viviparous: young develop within the uterus and are nourished by a yolk sac placenta, absorption of nutrients or eating other eggs. Osteichthyes (Bony fish): endoskeleton made of calcium phosphate, gills covered by operculum (protective flap), and air sac (swim bladder), to control buoyancy. TWO major groups: Actinoptergii - Ray-finned fish Actinistia - Lobe-finned fish Coelacanths Lungfishes Tetrapods: “four feet” body plan. ○ Four limbs and feet with digits. ○ Neck ○ Fusion of pelvic girdle to backbone. ○ Absence of gills  ○ Ears. 1. Amphibians - members of the clade Tetrapod. They have THREE classes of amphibians. Urodela: Salamanders, “tailed ones”. Anura: Frogs, “tailless” ones. Apoda: Caecilians, “leg-less” ones. 2. Reptiles - members of the clade Amniotes. Ex: tuataras, lizards, snakes, turtles, crocodiles and birds. ○ Birds - weight saving adaptations for flight includes: Wings and feathers Their bones are honeycomb and air filled. No urinary bladder. Only one ovary (females). Small gonads. Toothless mouths. 3. Mammals - members of clade Amniotes. They have THREE lineages. Characteristics include: ○ Glands that produce milk. ○ Hair. ○ Fat layer under skin. ○ Kidney that conserves water during waste removal. ○ High metabolic rate due to ENDOTHERMY ○ Large brain ○ Differentiated teeth. What are amniotes? What is the function of the embryonic membrane in an amniotic egg? Amniotes are tetrapods that include: Reptiles (including birds) and mammals. ○ Amniotes are named for the major derived character of the clade, the amniotic egg, which contains four membranes that protect the embryo: Amnion: protects embryo. Chorion: exchange of gas.  Yolk Sac: nutrients to embryo. Allantois: sac for metabolic waste. ○ What are monotremes? Marsupials, eutherians? Monotremes: egg-laying mammals. Marsupials: pouch mammals. Eutherians: placental mammals. ○ Primates - member of eutherians include: Lemurs (Madagascar) Tarsiers (Southeast Asia) Monkeys and apes (Arthropods) = Mr. Worldwide Orangutans, gorillas, chimpanzees. What are the characteristics of Hominids? Upright posture and bipedal locomotion. Larger brains capable of language, symbolic thought, and artistic expression. Production and use of tools. Reduced jawbones and jaw muscles. Shorter digestive tract. Know the examples of a few hominids you studied in class. Homo habilis, 1st human to make tools ○ Called “handy man”.  Homo ergaster ○ First fully bipedal, large-brained hominid. ○ Existed between 1.9 and 1.6 million years ago. Homo erectus originated in Africa 1.8 million years ago. ○ It was the first hominin to leave Africa. Homo neanderthalensis ○ Lived in Europe and near the east from 200,000 to 28,000 years ago. Chapter 40 What are the four types of tissue & their function? 1. Epithelial - covers the outside of the body, lines organs and cavities within the body. Different shapes: ○ Cuboidal (Dice) - secretions. Ex: Lining kidney tubules, thyroid and salivary glands. ○ Columnar (Bricks on red) - nutrient absorption and protection. Ex: lining of intestine, ciliated columnar epithelium lines the upper respiratory tract. ○ Squamous (Floor tiles): flat cells that exchange material by absorption. Ex: Lining blood vessels and air sacs of lungs. Different types: ○ Simple Epithelium: one layer of cells. Found where substances have to pass through, absorbed, filtered. Ex. Lines body cavity, ducts and tubes. ○ Stratified Epithelium: 2 or more layers of cells. Found where there is wear and tear……protection. Ex. Outer layer of skin, inner lining of mouth ○ Pseudostratified Epithelium: One layer but appears multilayered. Cells are short or tall…all attached to the basement membrane. Ex. Inner lining of trachea (windpipe). 2. Connective - mainly binds and supports other tissues. Connective tissue contains cells, including: ○ Fibroblasts - that secrete the protein of extracellular fibers. ○ Macrophages - that are involved in the immune system. There are THREE types of connective tissue fiber, all made of protein: ○ Collagenous fibers provide strength and flexibility. ○ Elastic fibers stretch and snap back to their original length. ○ Reticular fibers join connective tissue to adjacent tissues.  There SIX types of connective tissues: ○ Loose connective tissue - binds epithelia to underlying tissues, joins skin to muscle and holds organs in place. ○ Cartilage - is a strong and flexible support material. Cells called chondrocytes. Ex: ear-lobe, tip of nose, disc between vertebrates. ○ Fibrous connective tissue - is found in tendons, which attach muscles to bones, and ligaments, which connect bones at joints. ○ Adipose tissue - stores fat for insulation and fuel. ○ Blood - is composed of blood cells and cell fragments in blood plasma. Plasma contains: a. Erythrocytes = RED BLOOD CELLS, carry oxygen. b. Leukocytes = WHITE BLOOD CELLS, protection. c. Platelets = BLOOD CLOTTING. ○ Bone - is mineralized and forms the skeleton. Made of tiny tissue called Osteon. Each osteon has a central canal that has blood and nerves. Bone forming cells = osteoblast. Made up of calcium, phosphate and magnesium ions. 3. Muscle - consists of long cells called muscle fibers, which contract in response to nerve signals. There are THREE types of muscle tissue: ○ Skeletal muscle: muscle fibers form by fusion of muscle cells during development, so a fiber is multinucleated. Also called striated (cells are striped) Responsible for voluntary movement ○ Smooth muscle: is responsible for involuntary body activities. Not striated. Present in walls of digestive tract, arteries, internal organs… Responsible for involuntary body activities ○ Cardiac muscle: is responsible for contraction of the heart. Striated. Muscle fibers branch and connect via intercalated disc relays signal from cell to cell. Contraction of heart, involuntary movement. 4. Nervous - senses stimuli and transmits signals throughout the animal.  Nervous tissue contains: ○ Neurons, or nerve cells, that transmit nerve impulses. ○ Glial cells, or glia, that help nourish, insulate, and replenish neurons. ○ Nerve cells (neuron) made of cell body & 2 processes – dendrites and axon. ○ Dendrites - transmit impulses from the tip to the rest of the neuron. ○ Axons - transmit impulses towards another neuron or towards an effector such as muscle cell. ○ The nervous system: immediate and rapid responses to the environment. What is homeostasis/negative feedback? What is positive feedback and how does it happen? Homeostasis - “steady state”. Negative Feedback - is a control mechanism that “damps” a stimulus. ○ End product of the system shuts the system off. ○ Returns the variable to normal range or a set point. ○ Maintains internal temperature of humans. ○ Sugar levels in blood. ○ Water level in blood. Positive Feedback - amplifies a stimulus and does not play a major role in homeostasis. ○ Some change in condition causes the body to respond in a manner that amplifies the change. ○ Activation of digestive enzyme pepsin. ○ Fetus exerts pressure on the wall of the uterus, production & secretion of hormone oxytocin….muscle cells in the wall contract…childbirth. Define: Endothermic and Ectothermic, Estivation, Topor, Hibernation, Basal metabolic rate, standard metabolic rate. Endothermic - animals generate heat by metabolism; birds and mammals are endotherms. Ectothermic - animals gain heat from external sources; ectotherms include most invertebrates, fishes, amphibians, and non-avian reptiles. Estivation - also known as “summer torpor”. With slow metabolism and inactivity, this allows for animals to survive in high temperatures and scarce water. Topor - the physiological state of decreased activity and metabolism. Hibernation - “long-term” topor when physiological state of metabolism decreases, heart and digestive system slows down and body temperature is maintained at low level than normal. Basal Metabolic Rate - is the metabolic rate of an endotherm at rest at a “comfortable” temperature.  Standard Metabolic Rate - is the metabolic rate of an ectotherm at rest at a specific temperature. Chapter 41 What is homeostasis, malnutrition, over & undernourishment? Homeostasis - when your body is at a “steady state”. Malnutrition - is the long-term absence from the diet of one or more essential nutrients. Undernourishment - is the result of a diet that consistently supplies less chemical energy than the body requires. What are the stages of food processing? Ingestion - the act of eating. Digestion - break down food into molecules to absorb. Absorption - uptake of nutrients by cells. Elimination - undigested material passes through. What is the mammalian digestive system made of? Alimentary Canal: is what the mammalian digestive system is made of. ○ Various accessory glands that secrete digestive juices through ducts. Ex: Salivary gland, pancreas, liver and gallbladder. What is the function of the oral cavity, stomach, small intestine and the large intestine in digestion & absorption? Oral Cavity: the first stage of digestion. ○ Salivary glands and teeth help lubricate and break up food that gets exposed to salivary amylase to initiate glucose breakdown. Saliva consists of mucus which consists of water, cells, salts, and glycoprotein. ○ Pharynx (throat) - junction that opens to esophagus and trachea (windpipe). Trachea leads to lungs. Esophagus leads to the stomach by peristalsis. Peristalsis - rhythmic contractions of muscles in the wall of the canal. Stomach: stores food and secretes gastric juices to convert to acid chyme. ○ Chyme: mixture of ingested food and gastric juice. ○ Gastric Juice: pH 2.0 and is made up of hydrochloric acid and enzyme pepsin. Protease: protein digesting enzyme. ○ There are THREE types of cells in stomach: Parietal Cells: secrete hydrogen and chlorine ions separately.  Chief Cells: secrete inactive pepsinogen, which is activated to pepsin when mixed with hydrochloric acid. Mucous Cells: secrete mucus that protects the stomach lining from gastric juice. ○ Gastric Ulcers - lesions in the lining, are caused mainly by the bacterium Helicobacter pylori. ○ Sphincters prevent chyme from entering the esophagus and regulate its entry into the small intestine. TWO types of Sphincter: Cardiac sphincter: between esophagus & stomach. ○ The cardiac sphincter is weak…stomach acid backs up into the esophagus…heartburn. Pyloric sphincter: between stomach & small intestine. ○ Opens every 20 secs About 2-6 hrs to empty stomach. Small Intestine - is the longest section of the alimentary canal. It is the major organ of digestion and absorption. ○ THREE parts consist of: Duodenum (DIGESTION) - acid chyme from the stomach mixes with digestive juices from the pancreas, liver, gallbladder, and the small intestine itself. Secretes THREE hormones: Secretin: stimulates pancreas to secrete pancreatic juices Cholecystokinin or CCK: stimulates gallbladder to release bile into small intestine, stimulates pancreas to secrete pancreatic juices. Enterogastrone (Secretin & CCK): inhibits stomach peristalsis to slow down release of acid chyme. Jejunum and Ileum (ABSORPTION) - function in ABSORPTION in the small intestine. Large Intestine - the portion of the alimentary canal between the small intestine and anus. Functions in mainly water ABSORPTION and formation of feces. (Eww…) ○ Colon - also known as the large intestine, functions mainly in absorption and formation of feces. ○ Cecum - aids in the fermentation of plant material and connects where the small and large intestines meet. ○ Appendix - extension of cecum and contains massive white blood cells that contribute to immunity. What are the enzymes involved in digestion of carbohydrates, lipids, proteins & nucleic acids? Carbohydrates: Salivary Amylase → Pancreatic Amylase → Disaccharidases. Protein: Pepsin → Pancreatic Proteases (Trypsin/Chymotrypsin) → Pancreatic Carboxypeptidase → Dipeptidase, Carboxypeptidase, and Aminopeptidase. Nucleic Acid: Pancreatic Nuclease → Nucleotidase → Nucleotidase/Phosphatase. Lipids: Bile Salts → Pancreatic Lipase. How does the mechanism of digestion and absorption differ for carbohydrates, proteins & fats? Carbohydrates are broken down into glucose, proteins into amino acids, and fats into fatty acids and glycerol. These nutrients are then absorbed into the bloodstream and transported to the liver for processing and distribution to the rest of the body. Chapter 42: Circulatory System and Gas exchange What is an open & closed circulatory system? TWO types of circulatory systems: open or closed: ○ THREE basic components: A circulatory fluid (blood) A set of interconnecting vessels (blood vessels) A muscular pump (the heart) Open - the circulatory fluid, called hemolymph, is also the interstitial fluid that bathes body cells. Closed - blood is confined to tubes (vessels) and is different from the interstitial fluid. Are more efficient at transporting circulatory fluids to tissues and cells. Function of ventricles, atria, arteries & veins, AV valve, semilunar valve, sinoatrial node. There are THREE types of blood vessels: ○ Arteries - takes blood away from the heart. ○ Veins - brings blood back to the heart. ○ Capillaries - rejoins to form venules. Blood flows through the heart. Blood begins its flow: ○ With the right ventricle pumping blood to the lungs via pulmonary artery. In the lungs: ○ The blood loads O2 and unloads CO2 Oxygen-rich blood from the lungs: ○ Enters the heart at the left atrium via pulmonary vein. ○ Pumped to the body tissues by the left ventricle through the aorta. Blood returns to the heart:  ○ Through the right atrium. ○ Superior vena cava brings blood from the upper parts of the body (head, neck, forelimbs). ○ Inferior vena cava brings blood from the lower parts of the body (trunk and the hind limbs). What is blood pressure? What is the normal pressure in an adult human? Blood Pressure - is the hydrostatic pressure that blood exerts against the wall of a vessel. In rigid vessels blood pressure is maintained; less rigid, vessels deform and blood pressure is lost. Normal Blood Pressure in adult humans 120/70 mmHg. ○ Systolic: is the pressure in the arteries when the heart contracts (ventricular systole). highest pressure in the arteries. ○ Diastolic: Is the pressure in the arteries when the heart relaxes (diastole). Is lower than systolic pressure. Regulation of blood pressure - determined by cardiac output and peripheral resistance due to constriction of arterioles. ○ Vasoconstriction - is the contraction of smooth muscle in arteriole walls; it increases blood pressure. ENDOTHELIN is an import inducer.  ○ Vasodilation - is the relaxation of smooth muscles in the arterioles; it causes blood pressure to fall. NITRIC OXIDE is an inducer. Fainting is caused by inadequate blood flow to the head. What is the function of a pacemaker/SA node and AV node? Some cardiac muscle cells are auto rhythmic and self-excitable: ○ They contract without any signal from the nervous system. ○ Present in the wall of the right atrium. ○ This cluster of cells is called the sinoatrial (SA) node. Sinoatrial Node (SA): Pacemaker, sets the rate and timing at which cardiac muscle cells contract. Atrioventricular Node (AV): The impulses are delayed and then travel to the Purkinje fibers that make the ventricles contract. ○ Impulses that travel during the cardiac cycle can be recorded as an electrocardiogram (ECG or EKG). ○ The pacemaker is influenced by: Nerves, hormones (epinephrine), body temperature, and exercise. The pacemaker is regulated by the nervous system: the sympathetic and parasympathetic divisions. ○ Sympathetic (Fight, Flight or Freeze) - SPEEDS UP pacemaker. ○ Parasympathetic - SLOWS DOWN pacemaker. Why is the velocity of the blood lowest in the capillaries as compared to the arteries? Blow Flow Velocity: ○ Physical laws governing movement of fluids through pipes affect blood flow and blood pressure. ○ Velocity of blood flow is slowest in the capillary beds, as a result of the high resistance and large total cross-sectional area. ○ Blood from arteries →capillaries, velocity decreases. ○ Blood from capillaries → veins, velocity increases. ○ Lowest in capillaries…allows exchange of nutrients. Know the relationship between blood pressure and osmotic pressure in terms of fluid exchange between blood and the interstitial fluid. The difference between blood pressure and osmotic pressure drives fluids out of capillaries at the arteriole end and into capillaries at the venule end. Know the different tissues present in the arteries, veins and capillaries Central Lumen - a vessel’s cavity. Endothelium - epithelial layer that lines the blood vessel. It’s smooth and minimizes resistance. ○ Arteries and Veins: endothelium, smooth muscle, and connective tissue. ○ Capillaries: thin walls, the endothelium plus its basement membrane, to facilitate the exchange of materials. Components of blood & process of blood clotting  Plasma - liquid matrix of blood in which blood cells are suspended. ○ 90% water. ○ Contains dissolved ions called electrolytes. ○ Plasma proteins: influence blood pH, osmotic pressure, and viscosity. Ex. Albumin. Role in Immunity. Ex. Immunoglobulin or antibodies. Blood clotting. Ex. Fibrinogen Erythrocytes - transports oxygen. ○ Red blood cells, or erythrocytes, 5-6 million per cu, ml. most abundant blood cells. contain hemoglobin, the iron-containing protein that transports oxygen. Each molecule of hemoglobin binds up to four molecules of O2. Circulate for 120 days before they are replaced. Leukocytes - defense by phagocytizing bacteria and debris or by producing antibodies. ○ FIVE major white blood cells: 1. Monocytes - phagocytic. 2. Neutrophils - phagocytic. 3. Basophils - allergic reactions. 4. Eosinophils - allergic reactions. 5. Lymphocytes - T & B specific immunity. Platelets - are fragments of cells and function in blood clotting. ○ Blood Clotting - when the endothelium of a blood vessel is damaged, the clotting mechanism begins. Collagen fibers are exposed which attracts platelets. A cascade of complex reactions converts fibrinogen to fibrin, forming a clot. A blood clot formed within a blood vessel is called a thrombus and can block blood flow. Different cardiovascular diseases. Cardiovascular Disease - disorders of the heart and the blood vessels. Kills more than 750,000 people in the United States each year. ○ Atherosclerosis: Caused by the buildup of plaque deposits within arteries. Angina Pectoris is chest pain caused by partial blockage of the coronary arteries.  ○ Hypertension - high blood pressure. Promotes atherosclerosis and increases the risk of heart attack and stroke. ○ Heart Attack: Is the death of cardiac muscle tissue resulting from blockage of one or more coronary arteries. ○ Stroke: Is the death of nervous tissue in the brain, usually resulting from rupture or blockage of arteries in the head. Know the parts of the respiratory system. Air inhaled through the nostrils passes through the pharynx, larynx, trachea, bronchi, bronchioles, and alveoli, where gas exchange occurs. Exhaled air passes over the vocal cords to create sounds. Secretions called surfactants coat the surface of the alveoli. How is most (70%) of the CO2 transported in the blood? What is ventilation? What is negative and positive pressure breathing? Carbon dioxide transport: ○ Carbon dioxide from respiring cells → blood plasma → erythrocytes → carbonic acid → bicarbonate → alveoli → lungs. ○ 7% of CO2 transported in solution. ○ 23% binds to amino acids in hemoglobin. ○ 70% is transported as bicarbonate ions (HCO3 - ). Ventilation: ○ Increasing flow of water or air over the respiratory surface. ○ Water →mouth →gills → out of operculum. ○ Aquatic animals move through water or move water over their gills for ventilation. Positive Pressure Breathing - which forces air down the trachea.  ○ Amphibians: swallows air + pushes down into lungs + burps it out = PPB. Negative Pressure Breathing - which pulls air into the lungs. ○ Lung volume increases as the rib muscles and diaphragm contract. ○ The tidal volume is the volume of air inhaled with each breath. Control of breathing - main breathing controls are in TWO regions of brain: ○ Medulla Oblongata - regulates the rate and depth of breathing in response to pH changes in the cerebrospinal fluid. Adjusts breathing rate and depth to match metabolic demands. ○ Pons - regulates tempo. Inhalation: Rib muscles and diaphragm = CONTRACT. Exhalation: Rib muscles and diaphragm = RELAX. What is concurrent exchange and why is it important Fish gills use a countercurrent exchange system. ○ Gas exchange at the gill surface where blood flows in the opposite direction to water passing over the gills. As blood moves through the capillary, it picks up oxygen from the water. Pigments involved in gas exchange. Know the structure of hemoglobin and how it helps in oxygen uptake and release. Respiratory Pigments: ○ Are proteins that transport oxygen. ○ Hemoglobin (contains Iron)…vertebrates. A single hemoglobin can carry four molecules of O2, one molecule for each iron containing heme group. ○ Hemocyanin in Arthropods and molluscs contains copper as the oxygen binding component. ○ In vertebrates, hemoglobin is contained within erythrocytes. Chapter 43: Immune System What is innate, acquired immunity & their types, Pathogens - agents that cause disease. Immune system recognizes foreign bodies, responds by producing immune cells and proteins. An animal defend itself: ○ From viruses, bacteria & other pathogens.  TWO mechanisms of defense: ○ Innate Immunity: Present before any exposure to pathogens. Is effective from the time of birth. Nonspecific responses to pathogens. Found in all animals and plants: 1. Barrier defense – skin & mucous membrane, exoskeleton in insects. Oil & sweat glands → acidic pH inhibit → bacterial growth 2. Internal defense – macrophages & other phagocytic cells, antimicrobial peptides. White blood cells (leukocytes) engulf pathogens in the body. Phagocytic cells: types of white blood cells: Ingest invading microorganisms. Initiate the inflammatory response. There are different types of phagocytic cells: Neutrophils: engulf and destroy pathogens. Monocytes: develop into macrophages (big eaters). Eosinophils: defense against parasites. Dendritic cells: like macrophages, role in adaptive immunity in cells that contact the environment (skin). 3. Additional defenses are - natural killer cells, interferons and inflammatory response. Natural Cell Killers - They release chemicals leading to cell death, inhibiting the spread of virally infected or cancerous cells. Interferons ( α & β ) - defense against viruses and help activate macrophages. Inflammatory Response - such as pain & swelling, is brought about by molecules released upon injury or infection. Following injury: 1. mast cells release histamine, 2. which triggers blood vessels to dilate and allow more fluid.  3. more phagocytes, & antimicrobial proteins enter the tissues. Neutrophils digest the pathogens. 4. Tissue heals - Pus, a fluid rich in white blood cells, dead microbes, and cell debris, accumulates at the site of inflammation. ○ Adaptive (Acquired) Immunity: Develops after exposure to pathogens, toxins, or other foreign substances. Very specific response to pathogens. TWO Types: Cell mediated immunity – activation of cytotoxic lymphocytes. 1. T lymphocytes (T cells) that mature in the thymus. Each T cell receptor consists of two different polypeptide chains. The tips of the chain form a variable (V) region; the rest is a constant (C) region. Humoral immunity – activation of B cells - antibodies. 1. B lymphocytes (B cells) that mature in the bone marrow. B Cell Antigen: Binding of a B cell antigen receptor to an antigen is an early step in B cell activation. This gives rise to cells that secrete a soluble form of the protein called an antibody or immunoglobulin (Ig). Secreted antibodies are similar to B cell receptors but lack transmembrane regions that anchor receptors in the plasma membrane. Antigen - foreign molecule (protein or polysaccharide) recognized by lymphocytes and shows a response. A lymphocyte binds to a small portion of the antigen called an epitope. Exposure to the pathogen activates B and T cells with antigen receptors specific for parts of that pathogen. A single B cell or T cell has about 100,000 antigen receptors. What is the role of MHC, helper T cells, cytotoxic T cells, B cells, plasma cells, memory cells. CD4, CD8 surface protein? T Cells - bind to antigens that are bound to normal cell surface proteins called MHC molecules.  ○ Cytotoxic T Cells: Cytotoxic T Cells respond to Infected Cells & Cancer Cells. Class I MHC molecules, in nucleated cells of the body display peptide antigens to cytotoxic T cells. Cytotoxic T cells make CD8, a surface protein that allows interaction between an infected cell and a cytotoxic T cell. The activated cytotoxic T cell secretes proteins perforin that forms a pore & enzymes which destroys the infected target cell. ○ Helper T Cells: Produce CD4, a surface protein that allows their binding to class II MHC–antigen complexes on antigen-presenting cells. Antigen presenting cell engulfs and degrades a pathogen and displays it on MHC class II molecule and helper T cell then recognizes the complex, is activated. B Cells - a response to extracellular pathogens. ○ B cells are activated by cytokines (secreted by macrophages) and antigen binding to helper T cells. ○ B cells proliferate into 2 types of cells: Plasma cells (effector cells) – secrete antibodies into the bloodstream. Memory B cells – long lived…recognize the antigen during future encounters. Cell markers or MHC…differ in individual... used to distinguish between self & nonself…..role in organ transplant. Antigen-presenting cells have class I and class II MHC molecules on their surfaces. What is clonal selection? Clonal Selection - Is a process by which the immune system produces a large number of cells that are specific to a particular antigen. In a primary immune response, binding of antigen to a mature lymphocyte induces the lymphocyte’s proliferation and differentiation. ○ TWO Types of Immune Responses: Primary - The first exposure to a specific antigen represents the primary immune response. During this time, effector B cells called plasma cells are generated, and T cells are activated to their effector forms. Secondary - memory cells facilitate a faster, more efficient response. What are the antibody mediated responses to get rid of the antigen? Antibodies do not kill pathogens; instead they mark pathogens for destruction.  Antibodies may also bind to toxins in body fluids and prevent them from entering body cells. The binding of antibodies to antigens: ○ Is also the basis of several antigen disposal mechanisms. ○ Leads to elimination of microbes by phagocytosis and complement-mediated lysis. FIVE Types of Antibodies: 1. IgM: first to be produced. 2. IgG: common type against bacteria, viruses....crosses placenta….immunity to fetus. 3. IgA: secretions – saliva, tears, breast milk. 4. IgD: antigen receptor…activates B cells. 5. IgE: small amounts….allergic reaction stimulates mast cells & basophils. Mechanisms of disposal of antigens: ○ Neutralization occurs when a pathogen can no longer infect a host because it is bound to an antibody. ○ Opsonization occurs when antibodies bound to antigens increase phagocytosis. ○ Antibodies together with proteins of the complement system generate a membrane attack complex and cell lysis. ○ Agglutination: clumping of antigen What is active & passive immunity? Blood grouping. Allergic reaction, autoimmune diseases. What is an Immunodeficiency disease?—what cells are affected in HIV infection in humans Active Immunity: ○ Develops naturally in response to an infection. ○ Develop following immunization, also called vaccination. ○ Vaccines are inactivated bacteria or antigen…..immune response. Passive Immunity: ○ Immediate, short-term protection: IgG crosses the placenta from mother to fetus. IgA passes from mother to infant in breast milk. Injecting antibodies into a person. Blood Grouping: ○ Certain antigens on red blood cells. Determine whether a person has type A (A antigen), B (B antigen), AB (AB antigen), or O (neither antigen) blood. ○ Antibodies to nonself blood types exist in the body. ○ Transfusion with incompatible blood leads to destruction of the transfused cells.  ○ Recipient-donor combinations can be fatal or safe ○ Allergic Reaction ○ Are exaggerated (hypersensitive) response: To certain antigens called allergens. ○ In localized allergies such as hay fever: ○ Allergens stimulate B cells IgE. ○ IgE binds to mast cells → releases histamine → allergic response – sneezing, blocks nasal passage, watery eyes… Autoimmune Disease (AIDS): ○ The immune system develops antibodies against its own body cells → destroys them. ○ Autoimmune diseases include: Systemic lupus erythematosus: antibodies against histones and DNA. Rheumatoid arthritis - is an autoimmune disease that leads to damage and painful inflammation of the cartilage and bone of joints. Type 1 diabetes (insulin-dependent diabetes mellitus) - destroys the pancreatic cells that make insulin. Multiple sclerosis: attacks the myelin sheath in the central nervous system. Immunodeficiency: ○ Inborn immunodeficiency results from hereditary or developmental defects that prevent proper functioning of innate, humoral, and/or cell mediated defenses. ○ In severe combined immunodeficiency (SCID): Both the humoral and cell - mediated branches of acquired immunity fail to function. ○ An acquired immunodeficiency develops later in life and results from exposure to various chemical and biological agents Chapter 44 Osmoregulation Structure & Function of excretory function. Osmoregulation - regulates solute concentrations and balances the gain and loss of water. ○ Osmolarity - the solute concentration of a solution, determines the movement of water across a selectively permeable membrane. Iso Osmotic - movement of water is EQUAL in both directions.  Hypo Osmotic - LOWER solute concentration. Hyper Osmotic - HIGHER solute concentration. ○ Osmoconformers - DO NOT regulate their osmolarity. (ISO OSMOTIC). ○ Osmoregulators - use energy to control water uptake and loss. (HYPER/HYPO) Excretion - gets rid of nitrogenous metabolites and other waste products. ○ The type and quantity of an animal’s waste products may greatly affect its water balance. ○ Among the most significant wastes are nitrogenous breakdown products of proteins and nucleic acids. ○ Some animals convert toxic ammonia. ○ Ammonia excretion is MOST COMMON in aquatic organisms. Nitrogenous Wastes by animals: Aquatic Animals: excretes as AMMONIA through gills. Mammals: excreted as UREA. Reptiles/Birds: excreted as URIC ACID. Know the working of the kidney, the function of nephron, glomerulus, distal tubule, loop of henle, proximal tubule, collecting duct. THE KIDNEY… 1. Functions in both osmoregulation and excretion. 2. Each kidney is supplied with blood by a renal artery and drained by a renal vein. 3. Urine exits each kidney through a duct called the ureter.  4. Both ureters drain into a common urinary bladder, and urine is expelled through a urethra. Nephron - functional unit of the kidney that weaves across the medulla and renal cortex. ○ TWO Types of nephrons: Cortical - reaches only a short distance to medulla. Juxtamedullary - extends deep into medullary. Helps with production of urine that is HYPEROSMOTIC to body fluids. Glomerulus - single long tubule and a ball of capillaries. Bowman’s Capsule - surrounds and receives filtrate from the glomerulus. Know the route followed by the filtrate when blood is filtered through the excretory system Pathway of Filtration - filtrate passes through THREE regions: ○ The Proximal Tubule: Reabsorption of ions, water, and nutrients takes place in the proximal tubule. Molecules are transported actively and passively from the filtrate into the interstitial fluid and then capillaries. Some toxic materials are actively secreted into the filtrate. ○ Ascending Loop of Henle: The ascending limb has a transport epithelium that lacks water channels. Here, salt but not water is able to move from the tubule into the interstitial fluid. The filtrate becomes increasingly dilute as it moves up to the cortex. ○ Descending Loop of Henle: Reabsorption of water through aquaporin proteins into the descending loop by osmosis. No channels for salt or other solutes. Water is also reabsorbed into the descending loop by osmosis as the interstitial fluid surrounding the loop is hyperosmotic. ○ Distal Tubule: The distal tubule regulates the K and NaCl concentrations of body fluids. The controlled movement of ions contributes to pH regulation. ○ Collecting Duct: The collecting duct carries filtrate to the renal pelvis. One of the most important tasks is reabsorption of solutes and water. The collecting duct conducts filtrate through the osmolarity gradient, and more water exits the filtrate by osmosis. What are the hormones that affect urine production? Antidiuretic Hormone (Vasopressin) ○ An increase in blood osmolarity triggers the release of ADH, which helps to conserve water. ○ Decreased osmolarity causes a drop in ADH secretion, water is not reabsorbed resulting in a large volume of dilute urine.  ○ A high level of urine production is called diuresis. ADH opposes this state. ○ Alcohol is a diuretic, it inhibits the release of ADH. Renin - Angiotensin - Aldosterone System (RAAS) ○ It triggers the reabsorption of Na+ and water, restoring the blood pressure. ○ Dropping in blood pressure, Renin is made by the juxtaglomerular apparatus near the glomerulus. ○ Renin triggers the formation of the peptide angiotensin II. ○ Angiotensin II. Stimulates nephrons to increase Na+ and water reabsorption increases blood volume and pressure. Stimulates release of aldosterone, which increases blood pressure. Chapter 45 Hormones Know the major glands and hormones of the endocrine system. Know the action of the hormone antagonist pairs, like insulin/glucagon, and parathyroid hormone/calcitonin. Insulin and glucagon are antagonistic hormones that help maintain glucose homeostasis.  ○ Insulin reduces blood glucose levels by: Promoting the cellular uptake of glucose. Slowing glycogen breakdown in the liver. Promoting fat storage. ○ Glucagon increases blood glucose levels by: Stimulating conversion of glycogen to glucose in the liver. Stimulating breakdown of fat and protein into glucose. The pancreas has clusters of endocrine cells called islets of Langerhans with alpha cells that produce glucagon and beta cells that produce insulin. Parathyroid Hormone (PTH) - is released by the parathyroid glands when Ca2+ levels fall below a set point. ○ PTH raises the level of blood Ca2+. It releases Ca2+ from bone and stimulates reabsorption of Ca2+ in the kidneys. It indirectly affects Ca2+ by promoting production of vitamin D. ○ Calcitonin decreases the level of blood Ca2+. It stimulates Ca2+ deposition in bones and secretion by kidneys. Which organ has both endocrine and exocrine function? Pancreas Why do hormones act on only certain cells to which they are specific? Hormones are signaling molecules that bind to specific receptors on target cells, triggering a cellular response. The specificity of hormone action is due to the presence of receptors that are specific for that particular hormone on the target cells. Be aware that cells of neural origin often have endocrine ability. Be able to give examples of this. Chapter 48 and 49 The Nervous System Distinguish between the following pairs of terms: Central Nervous System - consisting of a small brain and longitudinal nerve cords. Peripheral Nervous System - consists of neurons carrying information into and out of the CNS.  White Matter - which consists of bundles of myelinated axons. Gray Matter - which consists of neuron cell bodies, dendrites, and unmyelinated axons. List the types of glia and their functions. Glial cells, or glia - have numerous functions to nourish, support, and regulate neurons. ○ Embryonic radial glia - form tracks along which newly formed neurons migrate. ○ Astrocytes - participate in the formation of the blood brain barrier, which restricts the entry of most substances into the brain. ○ Both can act as stem cells. ○ They undergo unlimited cell divisions to self-renew and form more specialized cells. What is the function of the cerebral spinal fluid? Clear, colorless liquid that fills the ventricles and central canal of the brain and spinal cord.  It is formed in the brain by filtering arterial blood and circulates through the ventricles and central canal before draining into the veins. The CSF supplies the central nervous system (CNS) with nutrients and hormones and carries away wastes. What is the limbic system and what is its function? Limbic System - generation and experience of emotions. ○ Parts of limbic system: Amygdala, Hippocampus and parts of Thalamus. Compare the three divisions of the autonomic nervous system and give their functions: Autonomic Nervous System - regulates smooth and cardiac muscles and is generally involuntary. ○ Sympathetic - regulates arousal and energy generation (“fight-or-flight” response). ○ Parasympathetic - has antagonistic effects on target organs and promotes calming and a return to “rest-and-digest” functions. Enteric Nervous System - control over the digestive tract, pancreas, and gallbladder. Describe the function/s of the following brain regions: Brain has THREE major regions: ○ Forebrain - has activities including processing of olfactory input, regulation of sleep, learning, and any complex processing. This divides into… Diencephelon → Endocrine tissues in the brain. Give rise to… Thalamus, Hypothalamus and Epithalamus. Telencephalon → Cerebrum which controls learning, emotion, memory and perception. Outer layer = cerebral cortex which is vital for perception, voluntary movement and learning.  ○ Midbrain - brainstem consists of: Mesencephalon → Midbrain Medulla Oblongata (Medulla) and Pons transfers information between PNS, midbrain and the forebrain. Control of several automatic functions such as breathing, heart and blood vessel activity, swallowing, vomiting, and digestion ○ Hindbrain - Metencephelon → Pons Myelencephelon → Medulla Oblongata Describe the specific functions of the brain regions associated with language, speech, emotions, memory, and learning.  Language and Speech: ○ Frontal Lobe Broca’s Area = understands language, cannot speak. Wernicke’s Area = unable to understand language, can speak. Describe the symptoms and causes of: i) Schizophrenia, ii) Alzheimer’s disease, and iii) Parkinson’s disease Schizophrenia: ○ Characterized by hallucination and delusions, ○ Affects neuronal pathways that use dopamine as a neurotransmitter. Alzheimer’s Disease: ○ Mental deterioration (dementia) characterized by confusion and loss of memory. ○ Associated with formation of amyloid plaques and neurofibrillary tangles in the brain. ○ Death of neurons and massive shrinkage in brain tissue. ○ No cure. Parkinson's Disease: ○ Parkinson’s disease is a motor disorder caused by death of dopamine-secreting neurons in the midbrain. ○ It is characterized by muscle tremors, flexed posture, and a shuffling gait. ○ Parkinson’s disease can be treated but not cured. ○ A dopamine-related drug called L-dopa can reduce the severity of Parkinson’s disease symptoms.