Flashcards in deck_1403681 Deck (286):
Types of plant tissue
1. Vascular tissue2. Ground tissue3. Dermal tissue
The plant body has a hierarchy of ___, ___, and ___.
Organs, tissues, cells
Components of the plant cell
1. Plasma membrane2. Cell wall - Primary cell wall - Secondary cell wall with lignin3. Plasmodesma(ta) - Channels that allow transport of food/hormones from cell to cell.
The three basic plant organs
1. Leaves2. Stems3. Roots
Two plant organ systems
1. Shoot system - Above ground2. Root system - Below ground
Plant cells store water in the ___ ___.
Characteristic of secondary cell wall
Not permeable by water, causing cell death following maturation.
- Anchors the vascular plant- Absorbs minerals and water- Often stores organic nutrients- May become photosynthetic + E.g., orchids
- Found in most plants- Occur at root tips where water/mineral absorption takes place- Increase surface area of root- Cannot absorb water if broken until they grow back
1. Prop roots - Develop above ground to create new shoots2. Storage roots - Store food and water3. Strangling aerial4. Buttress roots - Very large above ground5. Pneumatophores - Stick out of water to breathe
Two root systems
1. Fibrous roots - Monocotyledons2. Taproots - Dicotyledons
- Positions and supports leaf- May become modified to perform other functions
Anatomy of the stem
1. Apical/terminal bud - Located near the shoot tip and causes elongation of a young shoot.2. Axillary/lateral bud - Located at each node. - Meristems - Structure with the potential to form a lateral shoot, or branch.
- Apical shoots inhibit growth of lateral buds.- Lateral shoots will grow if apical bud is removed.
Place where leaf meets stem
Space between nodes
Undifferentiated plant cell
Modified shoot examples
Runner, strawberry, rhizomes, iris, tubers, potato, bulb, onion
If left out too long, potatoes will sprout ___ ___.
Contain a solid, underground stem. - E.g., garlic
- Main photosynthetic organ of most vascular plants.- Cuticle and stomata
Stomata opening formed by ___ cells.
Trichomes are also known as ___ ___.
Joins the leaf to a node on the stem.
Most monocots have ___ veins.
Most dicots have ___ veins.
- Simple- Compound + Pinnate + Bipinnate
One continuous blade
Blade is broken down into leaflets
1. Tendrils2. Spines3. Storage4. Bracts5. Reproductive
1. Tendrils2. Spines3. Storage4. Bracts5. Reproductive
Three tissue of plant organs
1. Dermal tissue2. Vascular tissue3. Ground tissue
Dermal tissue system
- Consists of epidermis (in primary growth)- Covered in cuticle
Vascular tissue system
Carries out long distance transport of material between roots and shoots. - Consists of xylem tissue and phloem tissue.
Transports water and dissolved minerals upward from roots to shoots.- Dead at maturity.- Leave behind (yellow/red) lignin at death.- Two types of xylem cells + Tracheids + Vessel elements
- Long, narrow, tapered cells with pits on the cell walls.
Short, wide cells with partially perforated walls.- Spiral-shaped
Transports organic nutrients (sugars) and hormones from where they are made to where they are needed.- Alive at maturity.- Sugars and hormones make up sap.Two types:- Sieve-tube members- Companion cells
- No nucleus- Only have cytoplasm- Cannot undergo mitosis- Contain sieve plates at their ends- Run next to companion cells
Control metabolism in order to keep sieve-tube members alive.- Undergo mitotis- 1:1 ratio to sieve tube members- Run next to sieve tube members- Typically dyed blue
Phloem and xylem run ___ to one another.
Includes various cells that can be used for storage, photosynthesis, support, etc.- Three types + Parenchyma (most common) + Collenchyma + Sclerenchyma
- Live at maturity with flexible primary cell wall- Metabolically active- Non-specialized and can divide to become other cells, but typically form xylem or phloem.- Common in vascular and ground tissue- Functions + Photosynthesis - Contain chloroplasts + Storage
- Live at maturity with unevenly thickened cell wall- Common in ground tissues of stems and petioles- Also associated with phloem- Function + Flexible support which allows for plant growth
- Dead at maturity with thickened cell wall containing lignin- Common in ground and vascular tissues- Cell types + Sclerids + Fibers - Long, tapered, non-digestible cells- Function + Support
Provide addition structure and support. - Variable shape
Long, tapered cells that are non-digestible.
Tissue organization of leaves
- Epidermal barrier + Interrupted by stomata which allow for CO2 exchange.- Ground tissue + Sandwiched between upper and lower epidermis.- Vascular tissue + Continuous with vascular tissue of the stem.
Leaf structure (all leaves contain...)
- Upper and lower epidermis + Both contain cuticle with guard cells and stomata. + Epidermis does not contain chloroplasts and so it needs to be fed.- Mesophyll (composed of Parenchyma cells) + Monocots have one layer + Dicots contain palisade and spongy parenchyma- Vein
Vascular bundle containing xylem and phloem.
Contain embryonic tissues that continuously generate cells for new organs. Work like stem cells.Types of meristems:- Shoot apical meristem + Elongate tips of shoots by primary growth.- Root apical meristem + Elongate tips of roots by primary growth.- Auxillary buds
Embryonic tissues leading to primary growth
- Protoderm- Ground tissue- Procambium
Gives rise to dermal tissue
Gives rise to ground tissue
Gives rise to vascular tissue
Growth in length of apical meristems at tips of roots and shoots.- Flexible- Eventually turns into secondary growth- Characteristic of all plants + Herbs only posses primary growth
Shoot apical meristems
Mass of dividing cells at the tip of the terminal bud.- Dome-shaped- Gives rise to the repetition of internodes and leaf-bearing nodes
Stem structure in primary growth
- Epidermis + One layer of cells and rarely more.- Cortex + Support tissues: - Collenchyma (live cells) - Sclerenchyma with fibers and sclerids (dead cells) - Parenchyma (live cells) + "Filler"- Vascular bundles + Xylem + Phloem + Procambium- Pith
Undifferentiated cells that form xylem and phloem.
Composed of parenchyma cells - Compose the center of the stem in monocots and dicots. - Compose the center of the root in monocots only.
In gymnosperms and dicots, the vascular bundles are arranged in a ___ shape.
Ring- These rings separate the pith from the cortex.
Characteristics of monocot stems
- Vascular bundles scattered throughout the ground tissue.- Closed vascular bundle- No vascular cambium- No secondary growth + Due to vascular bundles being surrounded by sclerenchyma cells.
Covers the root tip to protect the root apical meristem during primary growth. - Produce mucus to lubricate the root.
Root structure in primary growth
- Epidermis with root hairs- Cortex- Endodermis with Casparian strips- Stele + Vascular tissue- Movement of water and nutrients + Apoplastic pathway + Symplastic pathway
Space between epidermis and endodermis composed of ground tissue.
Two types of plant epidermis
- Upper- Lower + Typically faces away from the sun
Grow for one year and then die.
Grow for two years and then die.
Gives rise to vascular tissue (primary) - Everything below is phloem - Everything above is xylem
Dicot roots have xylem in the shape of a ___.
Stele (a.k.a. vascular cylinder) composition
Center portion of the root.From outside in:- Endodermis + One cell thick- Pericycle + One or more cells thick- Sieve tubes in phloem- Trachieds and vessels in xylem
The only structure that gives rise to lateral roots that emerge from within. - Lateral roots are those that shoot off from the main root.
Adds girth to stems and roots in woody plants.- Occurs in dicots but not in monocots- Occurs in stems and roots but not in leaves- Typically occurs after one year
Secondary plant body composition
Tissues produced by:- Vascular cambium- Cork cambiumVascular cambium and cork cambium are lateral meristems.
Apical meristems add ___ while lateral meristems add ___.
- Cylinder of meristematic cells- Phloem to outside, xylem to inside- One cell thick- Develops from original vascular cambium within the vascular bundles and some parenchyma cells within the cortex.- Mostly in stems and roots of dicots
Zone of division
Where mitosis occurs within the root.
Zone of elongation
Where root grow to potential size.
Zone of differentiation maturation
Where cells differentiate within the root to carry out particular functions.- Root hairs only occur at this zone.
Endodermis is ___ at maturity.
Act as capillaries to move water via capillary action.- Epidermal cells
Water and minerals are moved through the cytoplasm from cell to cell from the root hair to the xylem.
Water and minerals do not travel through the cytoplasm of the cells until they reach the later cells. The cytoplasm is made to act as a filter, but the apoplastic route bypasses this to increase speed.
Secondary growth production
- Vascular cambium undergoes mitosis to produce xylem to the inside and phloem to the outside. + Xylem and phloem cells do not undergo mitosis.- Primary phloem is crushed as the secondary phloem expands.- Primary xylem is pushed into the pith by the secondary xylem until the pith is completely gone.- Secondary xylem continues to grow inwards, causing the stem to expand in width.
Determining age in plants
Xylem cells shrink with lack of water. This causes a small ring of xylem to form during the winter.
Cylinder of meristematic cells.- One cell thick- Mostly in stems and roots of dicots- Develops from parenchyma cells in cortex- Forms cork to the outside until it ruptures the epidermis
- Contains lignin and suberin + Impenetrable by water or gasses- Dead at maturity- Contains lenticels
Breakages within the periderm which allow gases into the deeper layers of the plant tissue.
Cork and cork cambium
Periderm and living (secondary) phloem
Secondary xylem- Consists of sapwood and heartwood- Forms annual rings
Removal of ring of bark around the trunk of a tree to kill it. - Due to the removal of living phloem and so the roots do not receive food.
Grow in the direction of gravity (down) - Characteristic of roots
Grow opposite the direction of gravity (up) - Characteristic of shoots
Starches that attach to root cells. Must be at the bottom of the root, so the root grows to ensure this placement. This is the cause of gravitropism in roots.
Method of cutting and binding separate plants in order to form one hybrid plant.
Gas exchange mostly by these methods
- Stomata- Lenticles- Spaces between cells
Methods of fluid movement within xylem
- Adhesion- Cohesion- Evaporation- OsmosisPossibly due to capillary action, root pressure, or transpiration pull. Unidirectional from roots to tips.
Attraction between water molecules due to slight positive/negative charge.
Attraction between water molecules and the xylem walls.
Ultimately due to water rising upwards as a result of evaporation.
Open and close stomata. - Two per stomata, one on each side. - Contain chloroplasts.
Method of fluid movement within phloem
Fluids move by mass flow and is multidirectional.- Source vs. sink
Source vs. sink
Source may be a leaf, root, flower, etc. Active transport causes solutes to move to sieve-tubes. Water moves in to increase pressure, and bulk flow pushes solutes towards sink. Pressure and solute concentration decrease between source and sink, but solutes eventually reach the sink, lowering their water potential. Water enters the sink after the solutes.
- Undifferentiated cells.- Includes guard cells and other specialized cells- Present in primary growth but eliminated by secondary growth.
"Metazoa"- Eukaryotic- Multicellular- Heterotrophic- Lack cell walls- Only kingdom possessing nervous and muscle tissue.- Major groups: + Invertebrates + Vertebrates
Advantages of multicellularity
- Large size- Mobility- Stable internal environment- Relative independence from environment
Origin of Animalia
Derived from the "colonial choanoflagelate," a prostist.- Monophletic
Evolution of Animalia
- Colonial protist is an aggregate of identical cells.- Forms to become a hollow sphere of unspecialized cell.- Cell specialization begins, and some cells become somatic cells while others become reproductive cells. + Somatic cells form the body.- Infolding + Hollow sphere of cells folds inward on one end.- Gastrula-like "protoanimal" is formed. + Cavity caused by infolding becomes the digestive cavity.
Eumetazoa possess ___ unlike Parazoa.
- Cleavage + Radial - Always indeterminate + Spiral - Always determinate- Cell fate + Indeterminate + Determinate
Series of rapid cell division by mitosis and cytokinesis.
- Occurs in deuterostomes- Indeterminate- 8 cell stage composed of symmetrical stacking of cells of the same size.
- Occurs in protostomes- Determinate- 8 cell stage composed of smaller cells sitting on top of larger cells at an angle.
Developmental stages of Animalia
- Zygote undergoes cleavage until it becomes a morula.- Morula undergoes blastulation to become a blastula.- Blastula undergoes gastrulation to become a gastrula.
- Solid ball- Contains 64-100 cells- Undergoes blastulation
Cells of the morula move to the outside to increase the size of the ball, creating a blastula with a blastocoel.
Hollow ball of cells.
Hollow cavity within blastula.
Process in which the invagination of the blastula creates the gastrula.
- Possess a blastopore- Possess germ layers + Ectoderm + Endoderm + Mesoderm - Blastocoel is contained between ectoderm and endoderm and thus reduced.
Opening to the primitive digestive system, eventually developing into a mouth or anus.
Cavities that do not open to the exterior of the body.- Lining of coelom holds organs in place.- Surrounds heart, digestive, and respiratory structures in humans.Two types of formation:- Schizocoely- Enterocoely
Solid masses of mesoderm split to form coelom.
Mesoderm outpockets to form coelom.
Animal classification by four main attributes of body parts
1. Tissues2. Symmetry3. Body cavities4. Fate of the blastopore
- Lack true tissues- Typically asymmetricalTwo phylums only:- Placozoa- Porifera
- Possess true tissues
- Radial symmetry- Diploblastic + Endoderm and ectoderm
- Bilateral symmetry- Triploblastic + Endoderm, ectoderm, and mesoderm
Germ layers present in the gastrula develop into ___ ___ ___.
Adult body parts
Body cavity variation
- Acoelomate + No cavity- Pseudocoelomate + Cavity touches endoderm and mesoderm- Coelomate + Cavity touches medoderm
- Mouth develops from blastopore.- Spiral, determinate cleavage.- Schizocoely- Mesoderm derived from cells on lip of blastopore.
- Anus develops from blastopore.- Radial, indeterminate cleavage.- Enterocoely- Mesoderm derives from walls of developing gut.- All are coelomates.
Rapid appearance of most major animal phyla around 500 million years ago.
Means "poorly defined tissues."Includes:- Phylum Placozoa- Phylum Porifera
The most primitive metazoans.- Feed by absorption.- Marine, discovered by chance.
- Sessile- Filter water through canal system- Mostly marine- Possess an inner, middle, and outer layer.Classes:- Hexactinellida- Calcarea- Desmospongidae- Sclerospongiae
Large cavity in center of sponge. Water enters this cavity via the pores.
Opening on top of sponge through which water exits.
Sponge body layers
- Outer + Pinacocytes + Porocytes + Myocytes- Middle (Mesohy/mesogleal) + Spicules + Spongin + Amoebocytes- Inner + Choanocytes
Flat epidermal cells
Create the pore.
Allow the osculum to contract.
Gelatinous substance that contains the amoebocytes.
Used for support with a hard texture.
Used for support with a spongy texture.
Undifferentiated cells that form spicules and secrete spongin.- Form egg cells.- Receive food from coanocytes and pass throughout the sponge.
Flagellated cells that move water throughout the sponge.- Modified coanocytes form sperm cells.- Feed by trapping food particles in their collars and passing it to the amoebocytes. Amoebocytes then send food through the rest of the body.
Three body plans of sponges
- Asconoid- Syconoid- LeuconoidMore complex body plans allow for more surface area for food absorption.
Simplest body plan. Consists of a tube.
Tube with wavy extensions on its sides.
Most complex body plan. Matrix of canals with multiple osculums.
Characteristic of freshwater (and some marine) sponges. Trap the amoebocytes in the absence of water so that they can survive while the rest of the cells perish.- Result by asexual reproduction and hostile environments.
Larval stage of sponges.- Will not feed until they settle, which takes 2-3 days.
Asexual reproduction in sponges
- Budding- Regeneration
Sexual reproduction in sponges
- May be dioecious or monoecious- Sperm cells (modified coanocyte) enters another sponge and is engulfed by its coanocyte.- This coanocyte penetrates the egg cell, passing the nuclei of the sperm cell to create an embryo.- Embryo develops into an amphiblastula.- Larva settles and attaches to bottom or other surface.
"Glass sponges"- Contained 6 rayed spicules made of silica (glass)- Simple syconoids- Marine- Exist below 200 meters- Shrimp may become trapped inside- E.g., venus basket
"Calcareous sponges"- Spicules made of calcium carbonate- May be asconoid, syconoid, or leuconoid- Marine- Exist below 100 meters
- Comprises 80-90% of sponge species- Siliceous spicules and/or spongin- Mostly marine + Contains the only freshwater sponge families- Variable form- Leuconoids
- Found in tunnels in coral reefs + May damage reefs- Variable form- May contain silica and calcium carbonate spicules- Leuconoids- One group is predatory
Colors of sponges usually due to ___.
Mutualistic symbiosis in sponges
- Dinoflagellates + Zooxanthellae that perform photosynthesis for the sponge.
Bore holes into the host for shelter, killing it.Affect:- Hermit crab shells- Corals- Mussels and other mollusks
- Radiata- Possess mouth with tentacles- Blind gut + Mouth and anus are the same opening- Mesoglea gives them shape- Possess cynocytes- Diploblastic with organs- No respiratory system + Breathe by diffusion of gases through moist skin.- Excrete cellular waste via diffusion into the water.Classes:- Hydrozoa- Scyphozoa- Anthozoa
Morphology of Cnidarians
- Polyp + E.g., anemones- Medusa + E.g., jellyfish
Contain a coiled thread that is discharged when triggered.
- Nematocyst + Inject venom for feeding and protection- Spirocyst + Sticky thread for entangling prey- Ptychocyst + Create tubes for tube anemones
Structure containing the cnidae.
Interconnected neurons lacking a brain or cephalization.- Achieves little integration of information but serves simple behaviors.- Characteristic of Cnidarias, Ctenophors, and Echinoderms.
Cnidarian body plan
- Outer epithelium (epidermis)- Mesoglea (matrix)- Inner epithelium (gastrodermis)
- Mudusoid or polypoid + Polyp form is dominant + Alternate between medusa and polyp form- Polymorphic- Acellular mesoglea- Cnidae in epidermis- Nerve net- External fertilization- May produce male and female medusas but at different times- Possess planula- Asexual or sexual reproduction- E.g., Hydra (genus), Obelia (genus), man-o'-war
Medusa stage of hydrozoans that have both polyp and medusa stages. - Very small and found in some corals
Division of labor amongst the colonial polyps.- Gastrozoid: Ingest food- Gonozoid: Reproductive- Dactylozoid: Protective- Skeletozoid: Support
- Freshwater- Atypical + Single polyp- Polyp stage only- Asexual reproduction by budding- Not colonial
Genus Physallia- Colony of specialized polyps attached to tentacles, which are attached to a floating structure or sail (gas-filled medusa).
Ciliated larval stage of hydrozoans.
Life cycle of Obelia
Asexual via budding.Sexual:- Colony forms some reproductive polyps, called medusa buds.- Medusa, possessing gonads, is released.- Medusa undergoes meiosis to release sperm or egg into the water.- Sperm or egg come into contact with another gamete to create a zygote.- Zygote undergoes cleavage to form a planula.- Ciliated planula attached to surface and becomes a developing polyp.- Polyp reaches maturity and is able to reproduce asexually to create more polyps.
- Medusoid or polypoid + Medusa stage is dominant + Alternate between medusa and polyp form- Most common cnidarians- Cellular mesoglea- Cnidae in epidermis and gastrodermis- Gonads in gastrovascular cavity- E.g., jellyfish
Medusa form of Scyphozoa
Box jellyfish or sea wasp- Common in Australia- Venom paralyzes heart, muscles, and causes neurological damage in minutes.- Very small- Tentacles on 4 corners of bell
Upside-down jellyfish- Common in mangroves- Mutualistic symbiosis with green algae that live within its tissues (oral arms)
Scyphozoa life cycle
- Scyphistoma undergoes strobilation to produce ephyra.- Ephyra matures into an adult medusa able to produce egg or sperm.- Following fertilization, ciliated planula develops and attaches to a surface to form a young polyp.- Polyp develops into a scyphistoma.
Mature Scyphozoa polyp able to undergo strobilation to produce ephyrae.
Process by which the scyphistoma produces ephyrae.
Young medusa stage of Scyphozoa that develops into an adult medusa.
- Polypoid only- Cellular mesoglea- Cnidae in epidermis and gastrodermis- Contain septa (mesenteries) in gut- Skeleton of water- Capable of fission- E.g., corals and sea anemones
Radial partitions within the body cavity.
Splitting in two will create two separate organisms.
Life cycle of Anthozoa
Asexual:- Budding- Fission (longitudinal/transverse)Sexual:- Sperm and eggs released by colony into water.- Zygote develops following fertilization.- Planula for about 4 days.- Planula settles and polyp begins to develop.- Polyp undergoes budding to create a colony. + Colony takes 4-5 years to sexually mature.
Following budding, polyps remain ___ to one another.
Black band disease
Bacterial disease that kills coral.
Coral reefs are nutrient-___.
Corals have a symbiotic association with ___.
Algae - Zooxanthellae (particularly dinoflagellates)
"Coral forming" or "hard corals"- Stony, reef-building corals.- Possess zooxanthellae- E.g., Scleractinians and Hexacorallia
Coral reefs susceptible to deterioration by ___ and ___.
"Soft corals"- Octocorals and gorgonians- E.g., sea whip, sea fan, sea pen
"Comb jellies"- Medusa-like- Diploblastic- No nematocysts (usually)- 8 comb rows with retractable tentacles (usually) and fused cilia + Largest animal to use cilia for locomotion - Considered plankton- Colloblasts- BioluminescentTwo classes:- Tentaculata + Two tentacles- Nuda + No retractable tentacles
Sticky filaments that cover the tentacles and trap prey.
Characteristics of Eumetazoans with bilateral symmetry (applies to all phyla following this card)
- Cephalization + Nervous tissue is concentrated towards one end of the organism, producing a head region.- Triploblastic (3 germ layers) + Ectoderm + Mesoderm + Endoderm- Dorsal/ventral- Anterior/posterior
Three body forms found in bilateral organisms
- Acoelomate- Pseudocoelomate- Coelomate
Radiata are ___ while bilateria are ___.
"Flatworms" or planarians- Acoelomate- Gas exchange occurs through body surface- Hermaphroditic- Able to regenerate- Dorso-ventrally flattened to increase surface area- Incomplete digestive system + No anus- No respiratory system + Breathe by diffusion of gases through moist skin.- Possess protonephridia- Possess eye spotsClasses:- Turbellaria- Trematoda- Cestoda
Anatomy of a planarian
- Simplified cephalization with ganglia.- Eye spots to perceive light.- Pharynx connected to mouth at the center of the body.- Genital pore that leads to both male and female reproductive organs.
"Flame cells"Hollow cell containing cilia and used for cellular waste excretion. Cilia draws waste products in through a tube and filters it out through the membrane folds. Other cells are unable to enter the flame cell.
Asexual reproduction in planarians
- Fission + Each piece when cut regenerates into a new animal. Anterior or posterior will form depending on which end is cut. Cutting a certain portion too close to the head or tail may result in two heads or two tails. Splitting the head forms two heads.- Regeneration + Process of growing lost body parts.
Sexual reproduction in flatworms
- Mostly hermaphroditic- Hypodermic impregnation + Penis acts as a dagger to penetrate the skin of another worm and deposit sperm.
- Free-living + Not parasitic- Mostly small- Mostly marine- Possess Rhabdites + Cells unique to this class
"Flukes"- Parasitic- Syncitium + No separation between cells- Possess suckers- E.g., Schistosoma mansoni, liver fluke
Schistosoma (blood fluke) life cycle
- Mature flukes reside in blood vessels of human intestine.- Mating occurs in human and fertilized eggs are released in feces.- Eggs develop into "miracidium", which then infect snails.- Miracidium reproduce asexually, resulting in "cercaria."- Cercaria penetrate the skin of a new human host and develop into mature flukes.
Ciliated fluke larvae that prey on snails. - Cannot penetrate humans.
Fork-tailed fluke larvae that prey on humans.
Flukes cause ___ ___ in humans.
"Tapeworms"- Parasites- Lack digestive tract- Possess reproductive system- Possess excretory system- Possess a scolex- Possess proglottids- Hermaphroditic and able to self-fertilize- Usually only one individual + This is the reason for self-fertilization- May cause cysticerosis- E.g., fish, pork, and beef tapeworms + All can infect humans
Head of the tapeworm. Adheres to the intestinal walls by the use of suckers.
Segments of the tapeworm body that contain the reproductive organs.
Cestoda life cycle
- Mature tapeworm lives in human intestine.- Self-fertilizes to create mature proglottids with zygotes.- Proglottids released in feces and then burst, releasing zygotes onto the grass.- Cow ingests the grass with zygotes.- Zygotes develop into larvae and travel from digestive system to bloodstream and then to the muscle, where they encyst.- Human eats poorly cooked beef and ingests larvae.
Condition in which a human ingests a tapeworm zygote by eating vegetables. The larvae encyst anywhere they are able to.
Adaptations for parasitism
- Adhesive organs- Sense organs reduced- Digestive tract reduced or lost- Body wall protection- Larval stages in different animals allow for utilization of different habitats.
"Ribbon worms"- Pseudocoelomates- Possess a proboscis with stylet- Posses a "rhynchocoel"- Complete digestive tract + Posses mouth and anus- First to develop a closed circulatory system
Mouth that is able to shoot out to catch prey.
Spear at the end of the proboscis.
Cavity above the digestive system. It only has one entrance and contains the proboscis.
Closed circulatory system
Blood is contained within the blood vessels.
Sexual:- SpawningAsexual:- Fragmentation
If broken into multiple pieces, each piece becomes a new organism.
- Dioecious- Pseudocoelomates- Complete digestive tract- Multicellular- Microscopic- "Crown of cilia"- "Eutely"- Reproduce via "parthogenesis"- Possess a "peduncle"- Posses a bladder + Excretory organ
Born with the same number of cells that they'll have throughout their entire life.
Crown of cilia
Crown is covered in cilia which are used to bring in food for filter feeding.
Asexual reproduction via the development of the unfertilized egg of the female.
Structure that is used to attach to substrate. Able to retract when animal is motile.
"Roundworms"- Free-living and parasitic forms + Mostly parasitic - Affect flora and fauna- Dioeceous- Very abundant- Unsegmented- Vermiform + Cylindrical in shape- Complete digestive system- Small brain with lateral, ventral, and dorsal nerve cords- Use a specialized gland for their unique excretory system- Sexual reproduction- Longitudinal muscles from anterior to posterior + Allow for longitudinal whipping- Possess a cloaca
Common opening for reproductive, digestive, and excretory system.
Free-living nematode species
Caenorhabditis elegans - Important decomposers
Simplest, non-damaging nematode species
- Pinworms- WhipwormsThese stay within the intestines and do not migrate to other tissues.
Roundworm (Genus Ascaris) life cycle in humans
- Ingestion of water/vegetables contaminated by feces with roundworm eggs.- Eggs hatch and larvae migrate to intestine.- Larvae burrow through intestinal wall into the bloodstream of lymph ducts.- Larvae migrate to heart.- Larvae migrate to lungs.- Larvae are coughed out, swallowed, and return back to the intestine where they mature.- Mature roundworm sexually reproduces to create eggs, released in feces.
Roundworms ___ before leaving each new tissue.
Molt (4 times total)
Hookworms method of infection in humans
Penetrate the skin, not contracted via ingestion. - Intestinal parasites that, like roundworms, migrate to other tissues.
Nematodes that are microscopic until adulthood. Larvae within flies or mosquitoes are passed to the host where they mature. As they increase in size, they clog lymph ducts, trapping water in the tissues and causing swelling.Diseases caused by Filaria:- Elephantiasis- Larva migrans- Blindness
Caused by dog feces, often on the beach. Larvae enter via the skin and later emerge through the skin to release eggs. - May be pulled out with a pencil a little bit at a time, but breaking the worm will cause infection.
Larvae reside in pork muscle which is ingested. They then form calcified cysts in the human muscle.
- Schizocoely (like all protostomes)- Coelomate (like all protostomes)- Abundant aquatic and terrestrial forms- Sexual reproduction- Excretory system + Metanephridia (type of nephridium)- Open circulatory system + Except in Cephalopods- 2nd largest animal group- Shell (usually present) composed of periostracum, prismatic layer, and nacreous layer.- Head and muscular foot- Radula + Except in bivalvesClasses:- Monoplacophora- Polyplacophora- Gastropoda- Bivalvia- Scaphopoda- Cephalopoda
Metanephridia (type of nephridium)
Excretory gland that acts as a kidney. Consists of a series of tubes with open ends to filter fluid within the coelom.- Reabsorbs usable nutrients prior to the release of waste.- Mollusks possess 2.- Connects coelomic cavity to the pallial groove.
Gills and gut. Contains the internal organs and often protected by the shell.
Layer of living cells that secrete the shell.
The shell is composed of ___ ___ and ___.
Calcium carbonate, proteins
Mouth that is able to protrude and retract.- Full of teeth- Made of chitin
Contains the opening to the digestive, excretory, and reproductive systems.- Anus- Nephridium- Gills- Reproductive organs
Blood in mollusks.
Opening of the excretory system to the outside world.
Reproduction in mollusks
Egg or sperm develop in gonads and released into the coelom. Nephridia extracts them from the coelom and releases them into the mantle cavity so external fertilization can occur.
- Periostracum + External layer- Prismatic layer + Between periostracum and nacreous layer- Nacreous layer + Between prismatic layer and mantle
Form when sand or a parasite is inserted into space between nacreous layer and mantle. Mantle secretes nacreous layer around the foreign object, creating a pearl.
Larva stage of chitons and gastropods.
Larva stage of gastropods that contains a shell.- Develops from trochophore- No veliger stage in chitons
- Single conical shell- Uncommon- Mantle cavity located in space between foot and shell, surrounding entire foot.
"Chitons"- Means "many shells"- Suction to rocks to trap water in mantle cavity when the tide goes down. This allows the gills access to water.- Mantle cavity surrounds entire foot.
- Variable shell types- Twisted shell in species with shells + In these species, mantle cavity and anus located at anterior + Undergo "torsion"- 80% of all mollusk species- Aquatic species possess gills- Terrestrial species use diffusion of oxygen to exchange gas through mantle cavity and mantle wall.
The rotation of the visceral mass, mantle, and shell 180˚ with respect to the head and foot of the gastropod.
Shell types of gastropods
- Planospiral + Shell is flattened on both sides and coiled.- Heliospiral + Contain a helix and a spiral - E.g., conch- Shell-less + Mantle cavity at posterior - E.g., nudibranch
Mantle cavity is located at the ___ during the larval stage.
Terrestrial gastropods use ___ fertilization.
Marine gastropods use ___ fertilization.
- Dioeceous- Lack a radula- Complete digestive system- Siphons located in mantle cavity + Incurrent + Excurrent- "Umbo"- "Hinge ligament"- "Abductor muscles"- "Protractor/retractor muscles"
Raised bump at anterior of bivalve.
Opens shell slowly.
Close shell quickly.
Push foot out.
Bring foot in.
Characteristic of scallops able to detect light.
Bivalve that lacks a significant shell and burrows in wood.
Bivalve that attracts fish with a lure resembling another fish. Releases its parasitic larvae which then attach to the gills of the fish to draw blood.
Bivalve feeding mechanism
Filter feeders. Mucus on gills moves food particles to mouth, and waste is excreted via the anus near the excurrent siphon.
"Tusk shells"- Single, tusk-shaped shell- Burrowing
- Walk on their heads ("foot-head")- Shell absent, reduced, or spiraled- Tentacles/arms with suckers- Single siphon + Able to close and trap water- Closed circulatory system- Well developed eyes/eyesight- Intelligent- Beak- "Pen"- Ink gland- Chromatophores- E.g., cuttlefish, squid, nautilus, octopus
Modified, reduced shell.
The tube of the squid is the ___.
Mating in squids
Male uses his tentacle to retrieve sperm and injects it into the female in the form of a sperm sac. Male then makes a quick getaway.
Cells that contain pigment and are able to contract or expand in order to change the color of the organism. Surrounded by muscle that controls contractions.
- Oldest cephalopods- Only live in last shell chamber- Possess a chambered shell with siphuncle.
Tube that passes through the shell of nautiluses regulate gas flow and control buoyancy.
Octopi have no ___ body parts.
During this time there was an abundance of crinoids, nautiloids, and trilobites.