AP Biology –Semester II Final Review

1) DNA~determined to have two chains held by anti-parallel hydrogen bonds~two sides are made of a sugar (ribose) and a phosphate

*perpendicular steps are formed by nitrogenous bases called rungsA) Replication

~topoisomerase changes the surface of a coiled DNA (relaxes)~binding proteins protect and coat chains of DNA~replication begins at origin – a specific nucleotide sequence – and is

bidirectional*always proceeds in the 5’ to 3’ direction

~helicases unwind and melt DNA to break hydrogen bonds*opens the helix – replication fork

B) Synthesize~DNA polymerases I, II, III, IV are involved (enzymes: – “ase”)~strands are created in opposite direction: 3’ to 5’ direction~new strand created is started by a primer

*proceeded by nucleotides formed by RNA primase

~errors are made that are not complementary to the template strand*DNA polymerase proofreads and removes wrong nucleotides

2) RNA Overview

A) Transcription~this process makes RNA from DNA as well as mRNA, rRNA, and tRNA

*the DNA’s promoter (a starting sequence) beings RNA synthesis*same particulars pertain to DNA’s unwinding of the particular section (i.e.:

helicase; topoisomerase)~RNA polymerase adds nucleotides to the 3’ end of the RNA chain

*adenine now binds with uracil; only one strand is created~terminator will stop the production of the mRNA~mRNA will then enter Post-Transcription Modification

*introns (non-coding sequence) will be removed by enzymes; ligase enzymes will reassemble the mRNA

*exons (coding sequence) will be used to create a polypeptide*3’ end will be modified with a polyadenosine tail*5’ end is capped by a methylated phosphorylated guanine nucleotide; helps with

ribosome interaction~in mRNA, the matter between the polyadenosine tail and methylated phosphorylated guanine nucleotide is called the cistron

*mRNA will then leave the nucleus and enter the cytoplasm

B) Translation~the process that uses mRNA, ribosomes, and tRNA to make a polypeptide

*a linear sequence of nucleotides (codons) is translated into a linear sequence of amino acids (polypeptide)

~ribosomal units will attach to mRNA and then tRNA will attach to the corresponding codon (via anticodon)

~3 stages:1) Initiation~5’ end (AUG) of mRNA attaches to a small ribosome subunit

*initiator tRNA will attach with an anticodon (UAC) binding to the AUG codon (“start” codon)

*this three-molecule attachment is called the initiation complex~large ribosome subunit then attaches to the initiation complex (small subunit)

*tRNA is then trapped in the “P” site (Peptide site) leaving the “A” site (Aminoacyl site) open for the proceeding and corresponding tRNA to attach

~tRNA is shaped like a 3-leaf clover where its 3’ end terminates with CCA (amino acid attachment)

*the anticodon is located on the second “leaf”2) Elongation~process begins when the large ribosome subunit attaches the small ribosome subunit and a tRNA enters the initiation complex~the complementary tRNA binds with second mRNA codon occupying the “A” site and forming the beginnings of a polypeptide

*when both the “P” and “A” site are occupied, peptidyl transferase creates a peptide bond between the two amino acids

~ribosomes move down the mRNA chain by translocation*defined as the descending of an attached ribosome where the previously occupied tRNA in the “A” site becomes the tRNA in the “P” site; allows another tRNA to attach to a proceeding codon and create a polypeptide by the above process

3) Termination~process begins with one of the three “stop” codons and therefore ends the

polypeptide/protein synthesis*“stop” codons include UAA, UAG, or UGA

~no tRNAs exist that will attach to the termination codon*translation stops; polypeptide is released; two ribosomal subunits separate

3) Gregor Mendel

~first scientist to gather evidence using the garden pea*structure of the pea flowers prevented crosspollination*used only 7 characteristics that were major phenotypic distinctions*garden peas are characterized as rapid growers, many different traits,

cultivate easily, and breed easily~Thomas Morgan used fruit flies / Walter Sutton used grasshoppers / Richard von Hertwig used sea urchins to continue genetic research~his work was accepted with the improved of the microscope

*19th Century scientists did not see the significance of the calculations in concern with genetics

~lived during the same time as Darwin but neither knew of each other’s work*inherited characteristics are carried by discrete units called genes that are

reasserted in each generationA. Laws of Mendel

1) Law of Segregation: factors for a pair of alternative characters are separate and only one may be carried in a particular gamete; alleles separate in meiosis; (easy: allele pairs separate or segregate during gamete formation, and randomly unite at fertilization)2) Principle of Independent Assortment: when gametes are formed the alleles of a gene for on trait segregate independently of the alleles of a gene for another trait; (easy: allele pairs separate independently during the formation of gametes – traits are transmitted to offspring independently of one another)

4) The Punnett Square

~allele is a different form of a gene (i.e.: “R” or “r”)

*”Rr” is considered a (mono)hybrid organism~the phenotype or physical characteristic ratio is 3: 1

*dihybrid crosses have a 9:3:3:1 phenotypic ratio*purebreds have 1:0 pheno-/genotypic ratio

~the genotype of genetic representation ratio is 1:2:1~sexual reproduction is the source of variation

5) Genetic Mutations

~pleiotropy is an abnormal action of a single gene that can affect other physiological characteristics of the organism~recombination (crossing-over) is described as the exchange of portions of homologous chromosomes; beginning of meiosis; does not affect the order of genes

*genes that are on the same pair of homologous chromosomes stay together – called gene linkage (*)

A) Anomalies in Chromosome Structure1) Deletion: whole segments on a chromosome are lost; usually lethal2) Duplication: “lost” segments are put into homologue (same pairing) creating

the segment twice3) Translocation: a portion of chromosome is transferred to another nonhomologous chromosome4) Inversion: a double-break in a chromosome and the segment is turned 180o and

then reattachedB) Types of Chromosomal Disorders

1) Down Syndrome (Trisomy 21): extra 21st chromosome; shortened lifespan w/ mental and internal retardation (**)2) Cri Du Chat Syndrome: missing part of the 5th chromosome; infant has a cat-like cry3) Patau Syndrome (Trisomy 13): extra 13th chromosome; cleft lip and palate; polydactyl – extra fingers/toes4) Edwards Syndrome (Trisomy 18): extra 18th chromosome; motor and intellectual retardation; cannot walk/talk5) Jacobs Syndrome (Criminal Syndrome): (XYY); male w/ extreme height and acne; common in criminals6) Turners Syndrome: (X); lacks the second sex chromosome; child-like visage at in 20s and 30s7) Klinefelters Syndrome: (XXY) male; imperfect or non-functional testes8) Triple “X” (Super Female): (XXX); sometimes-sterile females with two Barr bodies versus the normal9) 14/21 Translocation Downs: extra 21st chromosome is attached to the 14th chromosome (**)10) Al Aish Syndrome: spontaneous abortion11) Philadelphia Chromosome: deletion of the 22nd short arm; associated w/ chronic myelogenous leukemia

6) Lac Operon

~created by the “I gene” of a DNA strand and is expressed in the presence/absence of lactose

*in the absence of lactose, the protein attaches to the DNA strand (called a lac repressor protein)

~(now a repressor) the Lac Operon blocks the transcription of mRNA by stopping RNA polymerase

*the blockade will insure that proceeding genes will not be transcribed – no RNA = no proteins

~in the presence of lactose, the operon’s shape is configured (closed)*cannot bind to a strand of DNA; RNA polymerase can transcribe an mRNA

strand = proteins1) the promoter is sequence on the DNA2) a repressor is a protein that stops RNA polymerase as it travels from the 5’

to 3’ end of DNA~an operon is a sequence/strand in DNA that codes of a specific sequence

(composed of genes)

7) Lytic and Lysogenic Cycle

A) Lytic Cycle (in Prokaryotes)~described as short and deadly; reproduction of viral~the prophage (or phage genome inserted as part of the linear structure of the DNA chromosome of a bacterium) will disassemble the host’s DNA; used for its replication

*proteins produce by transcription (mRNA etc) will made new capsids and viral enzymes

~capsids, proteins, and viral DNA are assembled*virons (individual nucleic acid core, enzymes, and capsid) are released

B) Lysogenic Cycle (in Prokaryotes)~extended cycle that can become the lytic cycle by chemicals (or U.V. light)~DNA inserted into the host and integrated into host’s chromosome

*DNA is then bequeathed during cell division (replicated)

8) Virus Overview

~all are considered parasites; they live off a host cell~composed of a nucleic acid core, enzymes, and a protein covering (capsid)

*each one is a viron*take over the host cell’s DNA and metabolism; rely on reproductive rate

~non-living with no cell structures (i.e.: nucleus, mitochondria etc.)*cannot use energy or reproduce independently from the host

~viruses mutate often (i.e.: influenza and AIDS)*the immune system does not recognize the surface protein

~antibiotics only kill infected living cells w/ cell walls; viruses do not have a cell wall

*a vaccine introduces a harmless imitation of the virus; act as antigens = create antibodies

A) The Process~First Response

1) the penetrated area becomes inflamed (redness/swelling)2) white blood cells (WBC or macrophages) eat the entering bacteria, infected

cells, and dead cells3) pathogens create a chain reaction of a defensive cell force (called antigens); these are recognized by WBC and are flagged by antibodies)

~Second Response*this is the body’s attack on a specific invader (pathogen = virus)4) WBC eats pathogen and creates an antigen flag (marker proteins that call

for helper T-cells)5) helper T-cells will match with the antigen flag*helper T-cells direct the production of killer T-cells and suppressor T-cells6) killer T-cells reinforce the WBC by puncturing infect (living) cells7) WBC then eats the dead (fragmented) cells9) B-cells circulating the body attach the WBC and match the helper T-cells10) B-cells will divide (approximately for 5 days) producing antibodies11) B-cells release antibodies that then attach the pathogen and infected cells;

marked specifically*a fever slows down the reproduction of the pathogen and increases the WBC

count in the specific area13) Suppressor T-cells will have been dividing simultaneously; halt killer T-cell

and B-cell production14) Memory B-cells remain for enhanced immunity

B) An Example~AIDS is caused by the HIV virus

*virus invades the helper T-cells which then become factories of HIV~weakens the immune system response; normal cells are uninfected

*diminished numbers of T-cells = no B-cell direction = no physical fight of a pathogen

~HIV can enter the Lysogenic cycle for up to 10 years and then lyses*transmitted only by blood fluids; cannot live outside the body

C) Retroviruses~the prefix, “retro,” refers to the reversal of transcription (RNA to DNA vs. DNA

to RNA)~an RNA virus that is replicated in a host cell (via reverse transcriptase) to produce DNA from its RNA

*reverse transcriptase is also known as RNA-dependent DNA polymerase; a DNA polymerase enzyme that transcribes single-stranded RNA into double-stranded DNA

~a retrovirus enters a host cell and provokes the RNA strands inside of the normally-functioning cell to undergo reverse transcription

*normally, DNA would transcript into RNA, and RNA would translate into proteins* when a retrovirus is inside of a cell, the first two steps of that process would be switched

~ reverse transcription lacks the usual proofreading of DNA replication, a retrovirus mutates often

9) Bacteria

~oldest group of organisms and the most numerous; populate the entire earth~general characteristics: prokaryotic (lack a nucleus); lack membrane-bound organelles; genetic material is in the form of plasmids (circular DNA); the cell membrane (lipid bilayer) lacks cholesterol; cell wall has no cellulose but is similar to plants

*cell wall is composed of peptidoglycan and muramic acid (tested by the Gram test)

*move either by flagella or pili~mitochondria contain their own DNA via plasmid (possible bacteria descendants)

*cell membrane is composed of the same enzymes; ribosomes have the same amino acid sequence; exhibit parasitism to make specific enzymes/proteins (like Cyanobacteria)

~Hans Christian Gram created the gram-positive and gram-negative tests~classified as bacilli, spirilla, or cocci

*diplococcus is cocci in pairs; staphylococcus is cocci in clusters; streptococcus is cocci in a chain

~reproduce by binary fission (asexual) or conjugation (sexual)*binary fission is the division of one cell into two (by prokaryotes)*conjugation is when bacteria’s exchange plasmids by temporarily linkage*spores are created by dormant resting cells (when food is scarce)

~heterotrophic bacteria are called sacrophytes (dead matter eaters) or parasites (feed on the living)

*decomposers break down organic matter – some by nitrogen fixation (nitrogen to useable ammonia)

~autotrophic bacteria obtain food by chemosynthesis*chemosynthesis oxidizes inorganic compounds into energy (i.e. methanogens

and sulferogens)

10) Protista

~composed of “evolved” bacteria; complex eukaryotes, autotrophs, and heterotrophs

*oxygen accumulated from Cyanobacteria (2.5 billion years ago)~general characteristics: unicellular; nucleus is separated from cytoplasm by a nuclear envelope; contains membrane-bound organelles; DNA associates with histone proteins~classification:

*photosynthetic autotrophs: Euglenophyta, Chrysophyta, Dinoflagellata, Chlorophyta, Rhodophyta, Phaeophyta*heterotrophs: Myxomycota, Mastigophora, Sarcodina, Ciliophora, Sporozoa

1) Euglenophyta: elongated cells with two flagella and green chloroplast; no cell wall; asexual reproduction

2) Chrysophyta: (golden brown algae/diatoms) cellulose/silicon cell walls; food in the form of oil

*diatoms are major group of eukaryotic algae, and are one of the most common types of phytoplankton; used in silver polish and toothpaste, testing of water quality, and studying an enviornment

3) Dinoflagellata: cellulose cell walls; two spinning flagella; cause of “Red Tides”*Red Tides is a disease that kills fish with a nerve toxin

4) Chlorophytes: (green algae) origin of plants*free-floating chlorophytes make-up the “pond scum”

5) Phaeophyta: (brown algae) seaweeds of temperate/polar areas; consist of stipe, holdfast, and blade

6) Rhodophyta: (red algae) most of the seaweeds of the world; attaches to rock; grows at -175m

7) Myxomycota: (slime molds/amoebas) live in the cool/decaying regions

8) Mastigophora: move by flagella; asexual/sexual reproducers; parasitic9) Sarcodina: move by pushed cytoplasm thru pseudopodia; can have shells

*move by phototaxis (away from light); chemotactic (chemical stimuli)

10) Ciliophora: contain cilia; micronucleus control reproduction; macronucleus directs metabolic functions11) Sporozoa: lack cilia and flagella; a type (plasmodium) causes Malaria

11) Fungi

~general characteristics: made up of masses of filaments (hyphae); cell walls are composed of chitin (found in exoskeletons); lack flagella or cilia; absorb nutrients that are either organic or inorganic

*reproduce either by asexual (spores/fragmentation) or sexual (fusion of gametes)

*nutrients are absorbed via the cell wall – secretion of enzymes~lichens are a compound (fungi/cyanobacterium/green algae)

*only needs light, air, and little minerals; survive when desiccated)

*a symbiotic relationship*reproduce by fragmentation

~mycorrhizae is a fungi attached to the roots of plants

*the plant provides the fungus with direct access to carbohydrates; translocated source to root tissue/fungal partners.*the plant gains the benefits of the mycelium's higher absorptive capacity for water and mineral nutrients*a symbiotic relationship

1) Zygomycota: spores germinate on bread/fruit~most are saprobes (organism that feed on dead matter)

*some are parasites of plants and insects~two main types:

a) rhiopus (rhizoids anchor into bread – black bread mold)b) sporanigophores (release spores into the air)

~reproduce by conjugation of hyphae (hormones are “+” or “–”)2) Ascomycota: (“sac fungi”) single-celled; largest division (30,000)~cause plant disease but are also a source of antibiotics

~asexual reproduction by spores call Conidia~sexual reproduction by Asco-spores via sac-like container (Ascus)

*two swellings (F: Ascogenium and M: Antheridium) will connect by bridge-conjugation (Trichogne)

*haploid nuclei exchange~formation of yeasts (creates ethyl alcohol by means of fermentation)

*vaginal infections – antibiotics kill bacteria normally inhabiting the vagina*ergot (initial source of LSD) causes muscles to contract and blood vessels to

constrict3) Basidomycota: (mushrooms and toadstools)~produce basidiospores by meiosis; Gill Fungi produce spores under the cap

*toxic mushrooms are eaten for hallucinogenic effects*toxic mushrooms (i.e. White Rot Fungus) is studied for environmental benefits

(degrades polymers)4) Deuteromycota: (penicillum) no known (lack thereof)sexual cycles~fungi are generally imperfect~causes athletes foot and ring worm~produces cheese and penicillin (antibiotic)

*cyclosporine is a compound which suppresses the immune system’s reactions*used (with success) in heart transplants

12) Alternations of Generations

A) Bryophyta: mosses1) haploid spore (n) germinates and absorbs water

*sprouts into the moss gametophyte called Protonema*gametophyte = large / sporophyte = small

2) protonema matures into a male or female moss*antheridium will produce sperm / archegonium will produce eggs*sperm will swim into the archegonium

3) fusion of sperm and egg creates a zygote (sporophyte)*sporophyte develops a foot, stalk, and a sporangium (produces spores to be

discharge)4) sexual reproduction by fragmentation is common

B) Pterophyta: Ferns

1) diploid sporophyte releases haploid spores into the wind*germinates (grows) in moist areas into a heart-shaped gametophyte called

Prothallus*gametophyte = small / sporophyte = large

2) Prothallus produce both antheridia and archegonia haploid gametes*sperm maneuvers into the archegonia to fertilize

3) diploid embryo develops into a sporophyte*self-fertilization is possible

C) Coniferophyta: Pines1) diploid pine tree (mature sporophyte) develops two cones

*male cone is small and produces microspores (undergo meiosis to form a small gametophyte)

*female cone is large and produces megaspores (undergo meiosis to form haploid gametophyte)

*gametophyte = small / sporophyte = large2) female cone secrets a stick substance for male pollen grains to attach

*immature male pollen grains will mature and form two sperm3) fertilization occurs after the male gametophyte forms a tube through the tissue of

the ovule*embryo forms into a sporophyte

4) cone matures, releasing the seeds dispersed by the wind

D) Angiosperms: Flowering Plants1) the dominant diploid sporophyte plants forms flowers

*flower holds reproductive structures2) anther produces haploid microspores (a 3-celled pollen grain)

*two cells in the sperm and one in a tube cell (called the gametophyte)3) ovule produces four megaspore in which one will develop into a embryo sac

*sac is called the gametophyte containing seven cells4) pollen will land on the stigma and a tube will descend to the ovary

*one sperm cell will fertilize the egg; the others will fertilize the polar nuclei creating endosperm (food/3n)

5) zygote becomes the embryo located inside the seed and the ovary develops into the fruit

13) Plant Hormones

1) Abscisic Acid (dormin)

~a plant hormone that responds to weather*slows down germination and tolerance to drought/coldness

~maintains a seedling/bud’s dormancy~protects against environmental conditions/stress2) Auxin (IAA or Indoleacetic Acid)~stimulates the growth of the xylem and phloem~produced by the apical meristem~can produce seedless fruit when applied to the ovarian walls3) Cytokinins~found in germinating seeds, meristems, fruits, and roots~causes cell division by affecting the rate of transpiration4) Ethylene~a hydrocarbon gas~ripens fruit by improving color and flavor~causes abscission (plants to drop leaves)5) Gibberellins~causes elongation of stems~during seed germination, it will causes enzymes to digest the endosperm

14) Leaves

~produce energy through photosynthesis*[6 CO2 + 6 H2O --- (ATP) --- C6H12O6 + 6 O2]* transferred by phloem to non-photosynthetic cells

~transpiration is the evaporation of water from the stoma*stomata regulate the change of gas by means of CO2

~translocation is the movement of carbohydrates~guttation occurs when there is a high soil moisture level, water will enter plant roots, nd the water potential of roots is lower than the soil

*water will accumulate in the plant, creating a slight root pressure, which forces some water to exude through special leaf tip or edge structures forming droplets

~abscisic acid is a plant hormone that responds to weather*slows down germination and tolerance to drought/coldness

15) Flowers

A) Reproduction1. anther releases pollen grains, which attach to stigma2. pollen divides into 2 nuclei: tube and generative nucleus3. tube nucleus creates a path to the ovule4. generative nucleus splits into 2 sperm cells5. two sperms follow the tube nucleus through the micropyle6. double fertilization occurs: one sperm fuses with the egg creating a zygote, the

second unties with two polar nuclei to form an endosperm~seeds are dispersed either during decay (indehiscent) or spontaneously (dehiscent)

*germination is dependent on light, oxygen, and temperature*the first structure produced from a seed is the root

~angiosperms have succeeded due to production of fruit, petals, and the ability to reproduce through various pollinations

*petals attract insects and animals

*self-fertilization, animal pollination, wind pollination, water-disperse pollination, and insect pollination*fruit

~imperfect flowers are flowers that only have one set of reproductive organs: either male or female

*staminate flowers contain only stamens*pistillate flowers only contain the pistil

~perfect flowers (bisexual) contain both a pistil and stamens; both male and female~complete flowers have sepals, petals, and stamens ~incomplete flowers lack one or more of such structures

16) Roots

~ an anchor, food storage unit, and water and nutrient absorption~root hairs are projections that absorb water and minerals in far distances (extension of xylem and phloem)

*absorb the most water of all plant structures~branch roots are an extension of the roots pericycle

Monocots DicotsEmbryo with single cotyledon Embryo with two cotyledons Pollen with single furrow or pore

Pollen with three furrows or pores

Flower parts in multiples of 3 Flower parts in multiples of 4 or

Major leaf veins parallel Major leaf veins reticulated Stem vascular bundles scattered

Stem vascular bundles in a ring

Roots are adventitious Roots develop from radicle

Secondary growth absent Secondary growth often present

~annual rings will expose “early” wood and late “wood” OR springwood and summerwood

*growing seasons will show in a lighter/darker coloration in the plant’s root wood

17) Stems

~support leaves and exposes them to sunlight; transport food, water, and minerals; supports above ground plant growth

*sclerenchyma supports young stems

A) Apical Meristem~the tip of a plant root that produces auxin and causes the shoot or root to increase

in length*growth that originates in the apical meristem: primary growth*protected by the root cap

~growth occurs by adding new xylem and phloem by the vascular cambium*primary growth is the elongation of a stem/root; addition of leaves, buds, and

branches*secondary growth (perennial dicots) increases thickness of the woody plants

~secondary growth comes from the vascular cambium

Vascular cambium divides

longitudinally

Vascular cambium creates xylem closer to the pith of the

B) Vascular Tissues~transpiration is the evaporation of water from the stomata

*stomata regulate the change of gas by means of CO2; opening and closing is regulated by potassium (K+)

*caused by osmosis/diffusion of water through the leaves of a plant due to heat*stomata close during wilting to prevent further water loss

~translocation is the movement of carbohydrates by the phloem~guttation occurs when there is a high soil moisture level, water will enter plant roots, and the water potential of roots is lower than the soil

*water will accumulate in the plant, creating a slight root pressure, which forces some water to exude through special leaf tip or edge structures forming droplets

~xylem moves water and ions*tracheids are primitive forms of water transport cells; cell walls have pits*vessel members have perforations between cells for osmosis; one continuous vessel; wider/shorter than tracheids

~phloem moves photosynthetic minerals to non-photosynthetic cells*sieve cells are a vertical column of cells joined by their walls; have pores that connect one another; lack a nucleus*companion cells are cells in contact with the sieve cells providing nuclear functions (nourishment)

~pressure-flow hypothesis diagram

Xylem enlarges

Vascular cambium divides again to produce

the phloem

Vascular cambium creates the phloem on the outer side of the

~cohesion-tension theory diagram

18) Lower Invertebrates

1) Profiera (literally means porebody)~example: sponges~one of the most primitive animals (no mouth or head); sessile animals

*have two germ layers: ectoderm (epithelial cells outer layer) and endoderm (innermost layer)

*epithelial cells make up the epithelium, the covering for internal (organs) and external body surfaces (skin)

~amoebocyte: cells that carry nutrients to the endoderm cells; remove waste~osculum: open pore for

water~spicules: small pointed

structure serving as a skeletal element in various marine and freshwater invertebrates

~spongocoel: central cavity of sponges

~choanocyte (collar cells): remove bacteria, algae, and microorganisms from water; digest removed substances with enzymes; filter feeding

~reproduction by gemmules or fragments (hermaphroditic)*gemmules (buds) are protected food-filled balls containing sponge cells*fragments are pieces of broken off sponge and experience regeneration

2) Plathelminthes~example: flatworms and planaria (non-parasitic flatworms) – acoelomates~cephalization is the concentration of sense receptors/nerves at the anterior end of

an animal*coelomates possess a coelom (segmented worm)*acoelomates have no coelom (flatworm)*pseudocoelomates have a cavity between the endoderm and mesoderm; no

epithelial lining (round worm)~Class Turbellaria are free-living planarias with an eyespot (Ocelli) and ganglion

*muscular system is derived from the mesoderm*cilia are present on the ventral side for movement over water*waste from cells is excreted by the flame cells – cilia beat in cells to move

material to the surface*hermaphroditic and capable of regeneration

~Class Trematoda consist of (blood) flukes*parasitic worms that live in or on the body of a host (endoparasitic)*do not have a digestive tract

~Class Cestoda are tapeworms (know parasitic flatworms)*no locomotion or digestive system*live in hosts intestines (absorb pre-digested food)*the head is called the scolex*segments of the body are call proglottid, which contain both male and female reproductive organs

*infection occurs for eating cyst-infected meat3) Nematoda~example: round worms (pseudocoelomates)~free-living organisms – some are parasitic

*33% of world population is infected by round worms*unsegmented, cylindrical organisms covered by a thick cuticle

~Ascaris worm enters the body via contaminated food or water*reproduce in the small intestine and organs’ wall

*2.5 months to reproduce (200,000 eggs/reproduction)~Hookworm bore larvae through the soles of feet

*have the ability to pass through the heart and lungs*feed on blood via the small intestine – eggs escape through the feces

~Trichinella cause trichinosis*cysts in uncooked pork are ingested – can be fatal*symptoms include pain, weakness of muscles, and high fever

4) Coelenterata (Cnidaria)~examples: jellyfish, sea anemones, and coral (reefs)

*around 9,000 species living as a polyp or medusa*have the simplest nervous system: nerve net

~tentacles (if present) have stinging cells called cnidocytes*contain a coiled stinger called the nematocyst, which discharges a poison to

capture prey~reproduce asexually (bud grows and detaches from original organism) or sexually

(sperm/egg)~radial symmetry with two cell layers: ectoderm (epithelia cells) and endoderm

(organs)*has a gastrovascular cavity used for digestion – secretes a digestive enzyme*undigested particles leaves through the

mouth~Sea anemones and Coral reefs belong to

class Anthozoa*only exist in polyp form (sessile organism)*produce limestone skeletons with the ability to form islands/reefs

*coral reefs only form at shallow waters because of the algae’s symbiotic relationship (photosynthesis)

Hydras belong to class Hydrozoa*have no brain, but a nerve net for muscle contractions; sensory cells (chemotropism and thigmotropism); basal disk secretes a sticky solution for attachment

~Jellyfish belong to the Scyphozoan class*contain the statocyst (receptor organ) which orients the animal in respect to gravity*incorporated with ocelli: a pigment with photoreceptor organs – located at the end of tentacles*some Scyphozoans produce a neurotoxin

5) Mesozoa~example: mesozoans~simple worms that are parasites

*related to the flatworms6) Rotifera~capable of spinning in water with tiny wheel-

like structures*females are parthenogenic (zygotes develop without fertilization of their eggs)

19) Higher Invertebrates

A) Annelids (segmented worms)~organ systems are present~segments have setae (bristles) for locomotion (expect leeches)~earthworms have a true coelom

*body cavity surrounded by the mesoderm – contains organs*dorsal brain (cerebral ganglion) and a ventral nerve cord

~reversed assembly line digestive system*crop holds the food*gizzard grinds the food

~respiratory system is a series of gas exchanges through the epidermis~circulatory system: five hearts connecting the dorsal and ventral vessels

*closed system – blood is contained in the vessels~excretory system consists of a nephridium in each segment

*removes wastes and urinates through the epidermis~contains a circular and longitudinal muscle system~hermaphroditic organism

*sperm are stored in the seminal vesicles*clitellum secretes mucus and channels the sperm to another wormforming a capsule/cocoon to protect and fertilize the eggs

~does not have skeletal system or endocrine systemB) Mollusca (50,000 species)~have soft bodies and gills for respiration (except land slugs and snails)

*triploblastic; bilateral symmetry; movement by “foot”*most are bivalves with a shell made of calcium carbonate

~bivalves: clams, scallops, oysters, and mussels*oysters (raw) can cause hepatitis

1) Gastropoda~includes the snails and slugs (univalves)

*has eyes at the end of the tentacles2) Cephalopoda~includes the octopi and squids

*octopi bite with a beak located at the center of the body; capable of producing a toxin; can be hermaphroditic; camouflage capable*squid are the largest mollusks; produce an ink for predators

C) Arthopoda (1 million species / 80% of all animals)~meaning “joint feet” – segmented body is fused (fewer than annelids)

*hard exoskeleton (made of chitin); dorsal heart with a ventral nervous system; muscle groups*compared to annelids: cuticle, coelom, organ systems, segmented body;

invertebrate, no endoskeleton~exoskeleton forms the body; open pores enable breathing and excretion

*molting: calcium is reabsorbed; blood flows to the posterior (claws shrink); emerge through a dorsal slit (helpless to predators)

1) Subphylum Arachnida~includes spiders, scorpions, ticks, and mites (feed on blood)~two body segments: cephalothorax and abdomen with four pairs of walking legs

*simple eyes (one lens), no antennae, chelicerae/pedipalps; respiration by book lungs

~spiders have celicerae (hollow fangs w/ poisons) and pedipalps (sensory receptors to stimuli; holds food)

*simple eyes (total: 8) detect light; spinnerets (ducts for silk glands) create webs; tracheae (book lungs) are respiratory tubes opening into the abdomen for breathing

2) Subphylum Crustacea~examples: lobster, crabs, crayfish, shrimp, and sow bugs~two pairs of antennae; three body parts head and thorax (fused: cephalothorax)

and abdomen*legs extend from the thorax and abdomen; found in water (gills); compound eyes

(multiple lens)*three pairs of mouth parts – chews sideways*claws/chelipeds are considered the first pair of “walking legs”*compound eyes (2,000 lens)

~body parts involve the cephalothorax and abdomen (in the crayfish…)*the carapace is the shell or shield-like covering*antennae are used for touch, taste, and smell – antennules at the base maintain

equilibrium (statocyst)*mandibles are the true jaws – maxillae are adapted to hew and move water over

gills*chelipeds or claws are used for defense and holding food (4 pairs of walking

legs)*swimmerets on the abdomen are for swimming and reproduction; same size =

female~the rostrom is in the anterior and used for digging

*uropod is the 6th pair of abdominal appendages*telson is the center of the tail fan

~an open circulatory system is made of 7 large arteries*colorless blood flows over organs and collects in the sinuses*vessels carry blood to the gills (means of respiration)

~excretory system: the green glands (in the head) that remove waste through a pore next to the antennules

~example: isopods (pill bugs, potato bugs, and the rolly pollies)*terrestrial crustaceans with a cuticle on the exoskeleton for water conservation*respiration by tracheae tubes – prefer dark environments

3) Subphylum Insecta (800,000 species – 70% of all species)~only invertebrates capable of flight

*advantages: high rate of respiration, adaptive to change, capable of flight~body is divided into three segments

*head has one pair of antennae*thorax has three pairs of legs (and maybe wings made of chitin)*abdomen has no legs but contain the reproductive organs

~eats by mandibles (grasshoppers), siphoning (butterfly), sponging/lapping (flies), or piercing (mosquitoes)

~the grasshopper belongs to the order Orthoptera (meaning straight-winged)*includes walking sticks, roaches, and the praying mantis*respires through spiracles, which are found on the first eight segments of the

abdomen1. Prothorax – first pair of walking legs2. Mesothorax – first pair of wings / second pair of walking legs3. Metathorax – second pair of wings / jumping legs

~spiracles lead to the trachea (air tubes) where oxygen goes in and carbon dioxide is expelled

~head includes more complex mouthparts than the crayfish (capability of “chew”)*labrum is the upper lip / labium is the lower lip*mandibles are jaws made for grinding (i.e. grasses)*the palps are touch sensory organs that hold food / maxillae hold and cut food

~two sets of eyes: compound and simple*three simple eyes above the base of the antenna – the one in between is the

ocelli*two compound eyes on the side of the head (made of six lens)

~one pair of antennae for smell, touch, and chemical detections~digestion system includes the esophagus, crop, salivary glands, gizzard, stomach (gastric caeca puts enzymes in the stomach), intestine, colon, rectum, and anus~excretion happens through the Malpighian tubes which pick up waste and puts

them into the intestine~contains an open circulatory system with a dorsal heart~hearing happens through the tympanus – an auditory membrane located on the

first abdominal segment4) Metamorphosis~incomplete metamorphosis includes 10% of insects (i.e. the grasshopper)

*egg becomes the nymph (adult-like w/o reproductive organs or wings)*nymph becomes the adult via molting

~complete metamorphosis includes the other 90% of insects (i.e. ants, bees, and flies)

*egg becomes the larva (immature form – i.e. caterpillar)*larva becomes the pupa, which is covered by a cocoon made of larva secretions*pupa opens the cocoon as the adult5) Subphylum Myriapoda (13,000 species) / Class Chilopoda (3,000 species)~example: centipedes~one pair of legs per segment with one pair of long antennae~simple eyes, carnivorous, and have a flat body

*kill prey with leg-manipulated appendages called jaws and chew w/ mandibles

6) Subphylum Myriapoda (13,000 species) / Diplopoda (7,500 species)~example: millipedes~two pairs of legs per segment with one pair of short antennae~simple eyes, herbivores, and have a round bodyD)Echinodermata (6,000 species)~meaning “spiny-skinned”~includes an endoskeleton w/o a backbone; complete digestive tract; radial

symmetry; triploblastic*respiratory system is composed of gills

~muscular system is composed of a water vascular system*supports the tube feet appendages*small projections of the body found on the sea star’s oral surface

~examples: starfish (Asteroidea), sea urchins, sand dollars, and sea cucumbers