Diversity of Life Flashcards
Gram-positive bacteria
- Stain dark purple
- Thick peptidoglycan layer in cell wall
- No outer (second) membrane
- Relatively small periplasm
- No (endotoxins) lipopolycaccharide (LPS)
- Secrete exotoxins
- Contain teichoic acids (acidic polysaccharide connecting peptidoglycan layer and plasma membrane for rigidity and structure
Gram-negative bacteria:
- Stain pink (due to counterstain)
- Thin peptidoglycan layer in the cell wall
- Contains periplasm between inner and outer membrane
- Outer (second) membrane present
- LPS present (an endotoxin release when bacteria is destroyed)
- Secrete exotoxins
- No teichoic acids
Cell wall of archea
No peptidoglycan present in cell wall, instead they contain some pseudomurein (a molecule that is analogous to peptidoglycan but with different peptide cross bridges)
Cell walls are also composed of sugars, proteins and inorganic molecules
Cell wall of eubacteria
Peptidoglycan present (a carbohydrate and protein polymer), encompassing the entire bacterial cell wall and allows for anchoring
The peptide and carbohydrate cross bridge linkages have D-amino acids that provide structural integrity
DNA organization of archea
- Circular
- Utilize histones and introns
DNA organization in eubacteria
- Circular
- Lack histones and introns
Endospores
- Produced by some bacteria
- A tough, non-reproductive structure that allows bacteria to enter a dormant state
- In the dormant state, the cell’s genetic material is preserved, allowing the cell to survive during times of extreme environmental stress
Fungus-like protists
- Lack a cell wall made of chitin
- Can move with flagella and cilia
- Saprophytic: feed on decaying matter
- Most live in moist soil
- Ingest food via phagocytosis
- Asexual reproduction and sporulation (spores produced have thick and strong cell walls allowing to resist environmental conditions
Plant-like protists
(algae-like protists)
* Among the most important primary consumers
* Photosynthetic autotrophs: produce organic matter from inorganic molecules using photosynthesis
* Examples: diatoms, euglenoids and dinoflagellates —> unicellular, photosynthetic autotrophs that reproduce asexually and are found in aquatic environments
Dinoflagellates
Responsible for red tide (toxins build up, oxygen in water is depleted)
Posses 2 flagella (find food in the absence of light)
Can parasitically infect certain animals (heterotrophic)
Animal-like protists
- Known as protozoa
- Eukaryotic (membrane-bound organelles)
- Unicellular
- Heterotrophic
- Move via flagella and cilia
- Often parasitic pathogens that infect and feed off a host organism (consume living cells or dead organic matter
- Contain food vacuole to store food
- Ingest food via phagocytosis
Kingdom fungi key features
- Heterotrophic sporophytes: feed on decaying/dead matter
- Posses a cell wall contain the polysaccharide glucan
- Have a predominantly haploid life cycle
Nonfilamentous fungi
- Yeast
- unicellular
- Reproduce asexually by budding
- Facultatively anaerobic: utilize fermentation in absence of oxygen to convert glucose to carbon dioxide and ethanol
Filamentous fungi
- Molds
- Multicellular and multinucleate
- Undergo aerobic respiration (require oxygen to gain energy from food)
- Reproduce sexually
- Form hyphae
Hyphae
Long, branching filaments that extend out to form a network of fungi (mycelium) with nearby fungi
› Collectivley all the hyphae are known as mycelium, which includes all connected spores
Septate hyphae
- Have septum dividing hyphae into multiple sections/compartments
- Causes the mycelium to look segmented
- Cell division occurs with cytokinesis which generates the individual septa as the cell grows
- Each compartment has a single nucleus
- Septa can close if injured and septa increases structural stability
Coenocytic hyphae
No septa present
One long continuous multinucleate cell (coenocyte)
Cell division occurs without cytokinesis
No septa allows for rapid nutrient diffusion
Phylum Platyhelminthes general characteristics and examples
- Reproduce sexually (hermaphrodites) or asexually (regeneration)
- Mainly aquatic habitats
- Parasitic lifestyle
- Most primitive of triploblasts
- Have organs
- Ex: tapeworms, flukes, planarian and flatworms (The Flat Planet Failed)
Phylum platyhelminthes body symmetry
Bilateral symmetry (can be split into equal right and left halves down the mid-sagittal plane) with cephalization (concentration of nervous/central organs in the brain/head)
Phylum Platyhelminthes tissue organization
Triploblastic (derived from three embryonic germ layers)
Eumetazoa
Phylum Platyhelminthes digestive system:
Gastrovascular cavity (one opening with two way digestion), except for tapeworms (they absorb food from surroundings)
Use a combination of extracellular (enzymes secreted into gastrovascular cavity, food particles breakdown) and intracellular (food particles engulfed and digested in food vacuoles) digestion
Phylum Platyhelminthes circulatory system
None- diffusion
Phylum Platyhelminthes respiratory system
None- diffusion
Phylum Platyhelminthes nervous system
Utilize two nerve cords (dense nerve bundle running along the length of invertebrates) and anterior centralized ganglia (brain)
Some planarians have eyespots
Phylum Platyhelminthes excretory system
Utilize protonephridia: bundle of flame cell that are involved in osmoregulation and filtering harmful substances from the body (function similarly to a kidney)
Phylum Platyhelminthes reproduction
Sexual reproduction: hermaphtodites (have both male and female sex organs
Asexual reproduction: regeneration
Phylum Nematoda general characteristics and examples
- Some utilize cuticles: flexible exoskeleton that prevents degradation by host digestive system
- longitudinal muscles (no circular muscles)
- Parasitic
- Not segmented
- Primarily reproduce sexually but some reproduce asexually through parthenogenesis
- Ex: round worms, hook worms and C. elegans, trichinella and ascaris
Phylum Nematoda body symmetry
Bilateral
Phylum Nematoda tissue organization
Triploblastic: derived from three embryonic germ layers
Pseudocoelomates: possessing a “pseudo” (fake) coelom —> utilized as a hydrostatic skeleton which allows for their locomotion (along with their longitudinal muscles)
Phylum Nematoda digestive system
Alimentary canal: complete, one-way digestive system from the mouth to the anus, including the esophagus, stomach and intestines
Phylum Nematoda circularity system
None- diffusion
Phylum Nematoda respiratory system
None- diffusion
Phylum Nematoda excretory system
None- diffusion
Phylum Nematoda nervous system
Utilize nerve cord and nerve ring (wraps around the esophagus)
Phylum Rotifera general characteristics and examples
- Not truly segmented
- Can reproduce sexually or parthenogenetically
- Small aquatic invertebrates organisms, mostly freshwater environments
- Draw food and water into mouth by beating motile cilia
- Feed on particular organic matter, protozoans, and dead algae
- Contribute greatly to nutrient recycling and are often used in cleaning fish tanks water
- Ex: Rotifer
Phylum Rotifera body symmetry
Bilateral
Phylum Rotifera digestive system
Alimentary canal: complete, one way digestive system from the mouth to the anus
Phylum Rotifera circulatory system
None-diffusion
Phylum Rotifera respiratory system
None- diffusion
Phylum Rotifera excretory system
Utilize protonephridia with flame cells (also use cilia to help with the filtering process)
Phylum Rotifera nervous system
Utilize a cerebral ganglia (brain) with some nerves extending through the body
Phylum Rotifera reproduction
Sexual reproduction
Asexual reproduction: parthenogenesis (virgin birth) where an underutilized egg develops into an offspring
Phylum Annelida general characteristics and examples
- The first phyla to develop segmentation
- Segmented bodies
- Coelom is divided by septa
- Longitudinal and circular muscles
- Ex: Earthworm, Leech, polychaete
Phylum Annelida body symmetry
Bilateral
Phylum Annelida tissue organization
Triploblastic
Coelomate: possessing a true coelom
Phylum Annelida digestive system
Alimentary canal: complete, one way digestive system with gizzard —> mechanical digestion of food before going to the intestines
Earthworms use crop for food storage, gizzard to grind food and intestine that contains typhlosole to increase surface area for absorption
Phylum Annelida circulatory system
(First phyla to posses a true circularly system)
Closed circulatory system: (blood always found in a vessel and never fills the body cavities) blood is pumped through vessels by the heart, multiple pairs of aortic arches and distinct arteries and veins
Phylum Annelida nervous system
Utilize ventral nerve cord and anterior ganglia (brain)
Phylum Annelida excretory system
Most have metanephridia: excretory glands for osmoregulation that make up the back bone of the excretory system. They are a series of tubes with cilia that move fluid, which then empty into coelom and eventually brought to the exterior via ducts
Phylum Annelida reproduction
Asexual: regeneration
Sexual: hermaphrodites
Phylum Annelida embryonic development
Protostome: blastopore forms the mouth
Determinant cleavage: fate of the cell is determined early on
Phylum Mollusca general characteristics and examples
- Visceral mass (mantle): thin tissue layer found within the shell and holds the bulk of organs, secrete calcium carbonate (can be used to make shells for a snail)
- Aquatic or land (terrestrial) habitats
- Hemocoel
- Ex: Clams, snails, slugs, squid, octopus, cephalopod, gastropod
Phylum Mollusca body symmetry
Bilateral
Phylum Mollusca tissue organization
Triploblastic coelomate
Phylum Mollusca digestive system
Alimentary canal
Radula: “tongue” covered in tiny teeth
Phylum Mollusca circulatory system
Open circulatory system
Blood goes to the hemocoel: space (separate from the coelom) within an organism where blood can flow freely around the internal organs
Phylum Mollusca respiratory system
Utilize gills
Phylum Mollusca nervous system
Utilize ventral nerve cords and central ganglia (brain)
Phylum Mollusca excretory system
Utilize nephridia: pair of osmoregulatory “kidneys”
Phylum Mollusca embryonic development
Protostomes: blastopore develops into the mouth
Spiral and determinant cleavage
Phylum Anthropoda general characteristics (all)
- Most diverse phylum with the highest number of different species
- three classes: class insecta, class arachnida, and class crustacea
- Arhtro- joint, poda- feet
- chitinous exoskeleton: complex carbohydrate exoskeleton outside of the body
- Segmented body
Phylum Anthropoda body symmetry (all)
Bilateral symmetry
Phylum Anthropoda tissue organization (all)
Triploblastic coelomate
Phylum Arthropoda embryonic development (all)
Protostomes: a shizocoelom formed by schizocoely
Phylum Arthropoda digestive system (all)
Alimentary canal
Some have salivary glands to help breakdown food and a jaw to mechanically breakdown food
Phylum Arthropoda circulatory system (all)
Open circulatory system: hemolymph
Phylum Arthropoda nervous system (all)
Utilize fused ganglia land ventral nerve cord
Class insecta general characteristics and examples
- Exoskeleton made of chitin
- Jointed appendages
- 3 pairs of legs
- One pair of antennae
- Many have wings
- More species than any other phylum combined
- Metamorphosis: distinct stages, altered appearance as insect matures
- Ex: ants, grasshopper and honeybees
Class insecta respiratory system
Utilize spiracles (small openings in the exoskeleton where air enters) and teacheal tubes (site of gas exchange) for respiration
Class insecta excretory system
Utilize malpighian tubes: small tubes found on the abdomen, function similarly to nephridia and kidneys, excrete uric acid
Class arachnida general characteristics and examples
- Four pairs of legs
- Chelicerae: specialized jaw structures that are used for eating
- Pedipalps: specialized arms used for a variety of different things (ex: defense and mating)
- terrestrial habitats
- Exoskeleton
- Jointed appendages
- Ex: spider, scorpion
Class arachnida respiratory system
Some utilize a trachael respiratory system
Some utilize book lungs: series of hemolymph filled plate-like structures (vascularized tissue) on either side to increase surface area for gas exchange
Class arachnida excretory system
Some utilize malpighian tubes
Some utilize coxal glands: osmoregulatory and excretory structures of nitrogenous waste
Excrete uric acid
Class Crustacea general characteristics and examples
- Aquatic and terrestrial habitats
- Jointed appendages (variable number)
- Exoskeleton
- 2 pairs of antennae
- Segmented bodies
- Ex: Lobsters, crayfish and crab, shrimp, barnacles
Class Crustacea respiratory system
Utilize gills
Class Crustacea excretory system
Aquatic: utilize green glands - osmoregulatory and excretory structures for nitrogenous wastes
Terrestrial: utilize malpighian tubes
Phylum Platyhelminthes coelom
Acoelomate (lacking a coelom, no body cavity present)
Diploblastic organisms
Have two cell layers: endoderm and ectoderm
no mesoderm
Nephridia
Pairs of osmoregulatory ‘kidneys’ found in invertebrates —> protonephridia and metanephridia are specific types of nephridia
What is the earliest phylum that is considered to be a coelomate?
Annelida
Mycelium
Network of fungi connected by hyphae
Schizocoelom
Type of coelom forms due to the separation of mesodermal cells during development
Organisms with this type of coelom formation undergo schizoely: a process in the embryonic development of protostomes
Enterocoelome
Type of coelom arises as a result of an out pocketing of the embryonic gut into the mesodermal space
Organisms that have enterocoeloms undergo enterocoely, a process in the embryonic development of deuterostomes
Endospores
Tough, non-reproductive structures bacterial species form to withstand desiccation, starvation, extreme temperatures, enzymatic destruction and chemical changes
It is a dormant state that allows bacteria to survive until they can energy from this state and become viable bacteria
First phyla to have an alimentary canal with one-way digestion
Nematoda
What is the first phyla to have accessory organs in addition to an alimentary canal?
Mollusca
Phylum Echinodermata general characteristics and examples
- Utilize a water vascular system: contain a central ring canal at center of body, radial canals going down their appendages, a madreporite where water can enter into the canals and tube feet found on ventral surfaces (can be expanded or contracted by the use of hydrostatic pressure, very rigid movement for walking and obtaining food)
- Water vascular system assists in gas exchange, nutrient exchange and waste exchange because water is being circulated throughout their body
- Closest related major phyla to chordates
- Only found in marine habitats (water)
- Ex: Starfish, sea urchin, sea cucumber
Phylum Echinodermata body symmetry
Adult: five fold radial symmetry
Larvae: bilateral
Phylum Echinodermata tissue organization
Triploblasic, coelomate, eumetazoa
Phylum Echinodermata digestive system
Alimentary canal: Complete, one-way digestive system (with an anus and mouth)
Phylum Echinodermata circulatory system
Open circulatory system with no heart
Phylum Echinodermata respiratory system
None- diffusion
Phylum Echinodermata excretory system
None- diffusion
Phylum Echinodermata reproduction
Asexual reproduction: regeneration
Sexual reproduction
Phylum Echinodermata embryonic development
Dueterostomes: blastopore forms the anus
Radial cleavage
Indeterminant cleavage: cell date isn’t determined early on
Phylum Echinodermata nervous system
Nerve ring and radial nerves
Phylum Chordata body symmetry
Bilateral
Phylum Chordata tissue organization
Triploblastic, eumetazoans (animals with true tissues, organs and digestive cavity), coelomate
Phylum Chordata embryonic development
Deuterostomes: blastopore forms the anus
Which phyla are protostomes
Annelida
Mollusca
Antrhopoda
Platyhelminthes
Nematoda
Rotifera
Which phyla are deuterostomes
Echinodermata
Chordata
Which phyla are neither protostomes or deuterostomes
Porifera
Cnidaria
Notochord
Shared trait of all chordates
Cartilaginous rod that supports the body during embryonic development and forms the primitive axis (most lose the notochord as they mature and is replaced by bone to form the spinal bones not the spinal cord)
what is the notochord derived from
The mesoderm
Dorsal hollow nerve cord
Shared trait of all chordates
Forms the spinal cord - develops into the central nervous system and brain
Pharyngeal slits
Shared trait of all chordates
Forms the pharynx, gills or other feeding structures and provides channels from the pharynx to other structures (or to the outside of the body)
In humans —> the pharyngeal slits forms the eustachian tubes and other head and neck structures
Muscular post-Anal-tail
Shared trait of all chordates
Lost during embryonic development in humans and many other chordates
Lancelets
(Also known as amphioxus or cephalochordata)
* Lack vertebrae: they keep the notochord through adulthood for structural support
* Marine organisms that occupy the benthic habitat (bottom of water)
Lancelets circulatory system
Closed circulatory system, lack a heart, and contain contractile blood vessels
Lancelets respiratory system
Diffusion through body walls
Tunicates
(Also known as urochordata)
* Sessile: immobile
* Filter feeders
* Live in benthic habitats
* Only have a notochord as larvae
Tunicates reproduction
Sexual: hermaphroditic
Asexual: budding
Tunicates circulatory system
Utilize both open and closed, contain a heart capable of changing direction of blood flow
Tunicates respiratory system
Respire through gills
jawless fish examples
(Also known as Agnatha)
* lamprey
* hagfish
Jawless fish circulatory system
2-chambered heart
jawless fish respiratory system
Gills
Countercurrent exchange within gills: blood flows opposite to water, allows for gas exchange through the entire length
Cartilaginous fish general characteristics and examples
(Also known as Chondrichthyes)
* Have jaws and teeth
* Skeleton made up of cartilage
* Ex: sharks and rays
Cartilaginous fish circulatory system
Two-chambered heart
Cartilaginous fish respiratory system
Gills
Countercurrent exchange
Bony fish general characteristics and examples
(Also known as Osteichthyes)
* Bony skeleton (skeleton made of bone tissue)
* Ex: salmon and halibut
* Include ray-finned fish (actinopterygii) and lobe-finned fish (sarcopterygii)
Bony fish circulatory system
Two-chambered heart
Bony fish respiratory system
Gills
Countercurrent exchange
Actinopterygii
Bony-fish: ray-finned fish
Most extant fish
Sarcopterygii
Bony fish: lobe-finned fish, lung fish, coelacanth
Amphibians general characteristics and examples
- No scales
- Undergo metamorphosis
- Ex: frogs and salamanders
Amphibians circulatory system
Three-chambered heart: to atria and one ventricle
Amphibians respiratory system
Larvae: gills
Adult: lungs and skin
Mammalia general characteristics
- Have hair
- Have mammary glands
- Four-chambered heart
- Lungs
- Most are endothermic: generate their own body heat
- Divided into three groups: monotremes, marsupial and placental mammals
Monotreme mammals general characteristics and examples
- least diverse
- lay eggs
- they sweat their milk and the young lick it off the mother
- platypus
- spiny anteater
Marsupial mammals general characteristics and examples
- young are born poorly developed, nourished by mother in pouch until they are developed
- kangaroo
- opossum
Placental mammals general characteristics and examples
- homeotherms
- nourish young via placenta: vascular organ found in uterus, connect to developing young via umbilical cord
- ex: bats, whale, mouse, humans
Non-avian reptiles general characteristics and examples
- internal fertilization
- cold blooded (poikilothermic): have internal temperatures that vary in response to external environment
- ectotherms: do not produce their own heat
- ex: sea turtle, snake, crocodile, alligator, lizards
Non-avian reptiles circulatory system
three-chambered heart
exception: crocodiles and alligators utilize a four-chambered heart
Non-avian reptiles respiratory system
Lungs
Birds general characteristics and examples
- oviparous: egg laying
- have pneumatizied bones: bones that are hollow and filled with air, making flight much easier
- modified forelimbs (often wings)
- eagle, blue jay, penguins
Birds respiratory system
Lungs with air sacs surrounding the lungs (makes the respiratory system more efficient)
birds circulatory system
Four-chambered heart
Phylum Cnidaria general characteristics and examples
- Occupy aquatic habitats
- Some have cnidocytes(cells shooting poisonous barbs)
- Some have life-cycles with a polyp stage: non-motile, reproducing asexually
- Ex: Hydra, jellyfish, sea anemone, coral
phylum Cnidaria body symmetry
Radial (around central axis)
Homeothermic
Animals maintaining a stable internal temperature in response to various external temperatures
Cephalization
Refers to organisms with a head
The head of a cephalic organism contains various sensory structures that connect to the central nervous system (brain)
echinodermata no not develop cephalization
What is the earliest animal in the subphylum vertebra
Jawless fish
Circulatory system of cephaloochordates
Closed circulatory system without a heart: blood travels by contractile blood vessels
Teichoic acids
Acidic polysaccharides found only in gram-positive bacteria
They connect the cell wall peptidoglycan to the cell membrane providing rigidity and structure
Asexual reproduction of fungi steps:
1) A haploid mycelium grows a haploid spore-producing structure
2) Haploid spore (conidia) produced
3) Conidia grow by mitosis and form myecilium that is genetically identical to the parent myecilium
Alternatively, fungi (or hyphae) are also capable of fragmentation or budding (regeneration)
Under which conditions do fungi reproduce asexually?
Under favorable environmental conditions
What is a defining characteristic of Cnidaria?
The presence of cnidocytes: stinging cells that function in prey-capture and predator defense
Plasmogamy
A process that marks the beginning of sexual reproduction in fungi where two hyphae of a mycelium fuse their cytoplasm, putting the two haploid nuclei (pronuclei) into one cell
The mesoderm is a cavity that lies between:
The mesoderm and the endoderm
An organism is classified as a coelomate if:
The coelom is surrounded by the mesoderm on all sides
Example of animal-like protists
- Rhizopoda: amoebas that move via pseudopodia and ingest food via phagocytosis
- Foraminifera: have shells made of calcium carbonate
- Amoeba: shapeless, unicellular and move via pseudopods
- Paramecium: group of ciliates that have specialized mouths which help them consume food
- Apicomplexans: parasites of animals, no mortality, causes malaria
- Ciliates: a paramecium that utilize cilia for mobility, and is most complex of all cells
Example of fungus-like protists
- Slime molds: can cellular or plasmodia’s that release haploid chores which haploid amoeba cells emerge from
- Water molds: oomycetes that are coenocytic (lack septa) and contain many nuclei within a single cell
phylum cnidaria nervous system:
nerve net: collection of nerves that are spread out with no brain
