Unit 4 Flashcards

Unit 3 Terms and Concepts 📚

Chapter 32: General Characteristics of Animals

  • General characteristics of animals

    • Animals are multicellular eukaryotes that are heterotrophic, obtaining their nutrients from other organisms.

    • They are characterized by the presence of a nervous system (in most), specialized muscle tissue, and the ability to move.

  • Tissues

    • Animals are organized into different types of tissues, including epithelial, connective, muscle, and nervous tissues.

  • Fungi vs. Animal Nutrition

    • Fungi digest food externally and then absorb nutrients, whereas animals typically ingest food and digest it internally.

  • Collagen

    • A structural protein that is the primary constituent of connective tissues, such as skin, cartilage, and bone.

  • Nervous and Muscle Tissue

    • Nervous tissue is responsible for transmitting signals throughout the body, while muscle tissue facilitates movement.

  • Diploid

    • The organism’s cells contain two complete sets of chromosomes, one inherited from each parent.

  • Symmetry

    • Characteristics based on body structure:

    • Asymmetrical: No symmetry; example includes sponges.

    • Bilateral: Symmetrical along a single plane; examples include humans and dogs.

    • Radial: Symmetrical along multiple planes; examples include jellyfish and sea urchins.

  • Germ Layers

    • Layers that form the various tissues and organs of animals:

    • Endoderm: The innermost layer, forming the gut lining.

    • Mesoderm: The middle layer, forming muscles and most internal organs.

    • Ectoderm: The outermost layer, forming the skin and nervous system.

  • Diploblastic vs. Triploblastic

    • Diploblastic organisms have two germ layers (ecto and endoderm).

    • Triploblastic organisms have all three germ layers (ecto, meso, endoderm).

  • Body Cavity Types

    • Coelom: A true body cavity lined with mesoderm; found in animals such as annelids.

    • Hemocoel: A blood-filled cavity; found in arthropods.

  • Organs

    • Specialized structures composed of different tissues working together to perform specific functions.

  • Cleavage

    • The series of rapid cell divisions that occur immediately after fertilization.

  • Blastula and Gastrula

    • Blastula: An early stage in embryonic development, characterized by a hollow ball of cells.

    • Gastrula: A later stage where the blastula folds inwards to form germ layers.

  • Larva

    • An immature form of an animal that undergoes metamorphosis to reach adulthood.

  • Metamorphosis

    • The process of transformation from larval stage to adult form.

  • Hox Genes

    • A group of regulatory genes that control body plan development and segmentation.

  • Protostome vs. Deuterostome

    • Protostomes: The mouth develops from the blastopore; includes arthropods and mollusks.

    • Deuterostomes: The anus develops from the blastopore; includes echinoderms and chordates.

  • Spiral vs. Radial Cleavage

    • Spiral Cleavage: Cells divide at an angle relative to the axis of the embryo, typical of protostomes.

    • Radial Cleavage: Cells divide parallel or perpendicular to the axis, typical of deuterostomes.

  • Determinant vs. Indeterminate Cleavage

    • Determinant Cleavage: The fate of the cells is determined early in division.

    • Indeterminate Cleavage: Cells can develop into a complete organism; typically seen in deuterostomes.

  • Blastopore - Mouth vs. Butt

    • In protostomes, the blastopore becomes the mouth; in deuterostomes, it becomes the anus.

  • Choanoflagellate Protist

    • Single-celled organisms considered the closest living relatives of animals.

  • Choanocyte

    • Specialized cells in sponges responsible for creating water currents and capturing food particles.

  • Cadherin

    • A type of cell adhesion molecule important in the formation of tissues.

  • Ediacaran Fossils

    • Fossils from the Ediacaran period that represent some of the earliest multicellular life.

  • Neoproterozoic Era of Animals

    • Period before the Cambrian, showing early multicellular life and simple animals.

  • Paleozoic Era of Animals

    • Followed the Neoproterozoic; diversification of marine life and emergence of terrestrial organisms.

  • Cambrian Explosion

    • Rapid diversification of life forms that occurred around 541 million years ago.

  • Mesozoic Era of Animals

    • Age of reptiles, including dinosaurs; saw emergence of mammals and birds.

  • Cenozoic Era of Animals

    • Current geological era; characterized by the dominance of mammals and birds.

Chapter 33: Invertebrates Overview

  • Ubiquity of Invertebrates

    • Invertebrates make up a significant majority of all animal species on Earth, representing diverse forms and adaptations.

  • Sponges (Porifera)

    • Simplest multicellular organisms; characterized by pores.

    • Sessile: Sponges do not move; they are fixed in one location.

    • Sequential Hermaphroditism: Can change sex during their lifetime.

    • Filter Feeding: Method of nutrition where sponges filter food particles from water passing through their bodies.

  • Comb Jelly (Ctenophora)

    • Marine invertebrates with eight rows of cilia for swimming; a unique form of symmetry.

  • Cnidaria

    • Includes jellyfish, corals, and anemones;

    • Mouth-butt: Cnidarians have a single opening that serves for both ingestion and expulsion of waste.

    • Medusozoa: Class of cnidarians that includes jellyfish.

    • Anthozoa: Class containing corals and sea anemones.

    • Hydra: A freshwater representative of Cnidarian.

    • Polyp: A sessile stage in the life cycle of cnidarians.

    • Cnidocytes and Nematocysts: Specialized cells containing stinging structures used for defense and capturing prey.

  • Acoela

    • A group of flatworms that are more simplistic than typical flatworms.

  • Lophotrocozoa

    • A clade that includes several animal phyla such as annelids and mollusks.

  • Flatworms (Platyhelminthes)

    • Fluke and Tapeworm: Parasitic flatworms with complex life cycles.

    • Fission: Asexual reproduction by splitting.

    • Simultaneous Hermaphroditism: Contain both male and female reproductive organs simultaneously.

  • Rotifer (Syndermata)

    • Tiny animals with a crown of cilia used for feeding, known for their resilience.

    • Trophi: Specialized jaw structure for feeding.

    • Parthenogenesis: A type of asexual reproduction where females produce offspring without male fertilization.

  • Bryozoan (Ectoprocta)

    • Aquatic invertebrates that live in colonies and are identified by their lophophore (feeding structure).

  • Lophophore

    • A crown of ciliated tentacles surrounding the mouth, used for feeding in certain invertebrate groups.

    • Colony: Many individuals living together, often connected by a tissue layer.

  • Brachiopods (Lamp Shell)

    • Marine animals with two shells similar to clams; prevalent in the fossil record.

  • Mollusca

    • Diverse group of animals characterized by a soft body and often a hard shell.

    • Foot: A muscular structure used for movement and attachment.

    • Visceral Mass: The part of the body containing internal organs.

  • Polyplacophora (Chiton)

    • Mollusks with eight overlapping shell plates on their dorsal side.

  • Radula

    • A toothed, chitinous ribbon used by mollusks to scrape food.

  • Dorsal Plates

    • Protective plates located on the back of some mollusks such as chitons.

  • Gastropoda

    • Largest class of mollusks, includes snails and slugs with a distinct coiled shell or no shell at all.

    • Foot Cilia: Cilia found on the foot of some gastropods aiding in locomotion.

  • Bivalvia

    • Mollusks with two hinged shells; important ecological cleaners via filter feeding.

    • Hinged Valves: Shells that open and close to allow feeding and movement.

  • Cephalopoda

    • Highly intelligent mollusks, including squids and octopuses.

    • Siphon: A structure used for propulsion and respiration.

    • Variable Shell of Cephalopods: Can range from reduced to absent in some species; important for adaptation.

    • Social Learning: Notable behavior seen in cephalopods, emphasizing their intelligence.

    • Tool Use: Evidence suggests some cephalopods can use objects in their environment for problem-solving.

  • Annelida

    • Segmented worms with a complex body structure that includes a coelom.

    • Segmented: Body divided into repeated segments allowing specialization.

    • Deposit Feeder: Obtain nutrients from soil or sediment.

    • Suspension Feeder: Filter food particles from water.

  • Ecdysozoa

    • A group characterized by molting or shedding of their outer layer (cuticle).

    • Cuticle: A hard outer covering found in groups like arthropods and nematodes.

    • Molting: The process of shedding the old exoskeleton or cuticle.

  • Tardigrada

    • Known as water bears, small segmented animals known for their resilience to extreme environments.

  • Nematoda (Roundworm)

    • A diverse group of roundworms; many are important as model organisms in biological research.

  • Arthropoda

    • The largest phylum in the animal kingdom, characterized by an exoskeleton, segmented bodies, and jointed appendages.

    • Exoskeleton: A hard outer covering made of chitin providing structural support and protection.

    • Paired Jointed Appendages: Limbs that allow for complex movement and adaptation to various environments.

    • Trilobites: Extinct marine arthropods serving as important fossils.

    • Chitin: The main component of the exoskeleton of arthropods.

    • Chelicerates: A group within arthropods; commonly includes spiders and horseshoe crabs.

    • Myriapods: Includes centipedes and millipedes; characterized by many body segments and legs.

    • Millipedes vs. Centipedes: Millipedes are primarily detritivores, while centipedes are predators.

    • Pancrustaceans: Includes crustaceans and hexapods (insects).

    • Barnacle Sex: Unique reproductive methods among barnacles due to their sessile nature.

    • Insects: The most diverse group of arthropods; adaptations include wings.

    • Insect Wings: Evolved structures allowing for flight; crucial for dispersal and survival.

    • Evolution of Insects Following Evolution of Plant Groups: Insect diversity closely linked with flowering plant evolution.

    • Metamorphosis: Dramatic transformation that occurs in some insects between stages.

  • Echinoderms

    • Marine invertebrates with a unique water vascular system and pentaradial symmetry.

    • Endoskeleton: Internal skeleton made of calcareous plates.

    • Calcareous Plates: Provide structure and support.

    • Water Vascular System: A network of canals crucial for locomotion and feeding.

    • Tube Feet: Extensions used for movement and feeding.

    • Bilateral à Quasi-Radial: Developmental transition from bilateral symmetry to radial in Echinoderms during maturation.

    • Sea Cucumber Predator Defense Strategy: A method involving expelling internal organs to distract predators.

  • Hemichordates

    • A group of marine animals that share characteristics with both echinoderms and chordates.

Chapter 34: Chordates Overview

  • Derived Characteristics of Chordates

    • Traits unique to chordates including:

    • Notochord: A flexible rod-like structure providing support.

    • Dorsal, Hollow Nerve Cord: Develops into the spinal cord and brain in vertebrates.

    • Pharyngeal Slits or Clefts: Openings that lead from the pharynx to the outside; serve various functions in different species.

    • Muscular, Post-Anal Tail: Structure used for movement in many species.

  • Lancelets (Cephalochordata)

    • Small, fish-like invertebrates; demonstrate the chordate body plan.

  • Tunicates (Urochordata)

    • Marine animals that exhibit chordate characteristics in the larval stage but lose them in the adult stage.

  • Hox Genes

    • Genes that regulate the development of body structures; critical in determining the anatomy of the organism.

  • Neural Crest

    • A group of cells that develop from the ectodermal layer and contribute to the formation of various structures including facial features.

  • Vertebrates and Cambrian Explosion

    • Vertebrates appeared during the Cambrian explosion, leading to increased diversity and complexity in aquatic life.

  • Haikouella and Myllokunmingia

    • Early chordate fossils providing insights into the evolution of vertebrates.

  • Conodont

    • Extinct jawless vertebrates known from their tooth-like structures; representative of early vertebrate evolution.

  • Agnatha

    • Jawless fish category including:

    • Hagfish: Known for their slime production and scavenging behavior.

    • Lamprey: Parasitic or free-living; have sucker-like mouths.

  • Vertebrae

    • Bony or cartilaginous structures forming the backbone of vertebrates.

  • Backbone

    • Provides structural support and houses the spinal cord.

  • Scales

    • Protective coverings of fish and reptiles; formed of keratin and provide advantages in survival.

  • Cartilage

    • A flexible connective tissue found in various parts of the body, including the skeletal system of many vertebrates.

  • Gnathostomes

    • Jawed vertebrates that represent a major evolutionary event in chordates.

  • Lateral Line System

    • A system of sensory organs found in aquatic vertebrates that detects water movements and vibrations.

  • Placoderms

    • Extinct armored fish showing early signs of jaws.

  • Cartilaginous Fishes (Chondrichthyes)

    • Include sharks and rays; possess a skeleton made predominantly of cartilage rather than bone.

    • Bone Within Cartilaginous Fishes: Some species have bony structures for buoyancy or defense.

    • Electrical Field Detection: Ability to sense electrical signals in the water, crucial for hunting.

    • Oviparous: Egg-laying species;

    • Ovoviviparous: Eggs hatch inside the female; live births occur.

    • Viviparous: Species that give live birth without producing eggs.

  • Ray-finned Fish (Actinopterygii)

    • A diverse group of fish characterized by bony rays supporting their fins.

    • Operculum: A bony flap covering the gills.

    • Swim Bladder: A gas-filled organ that helps regulate buoyancy.

  • Lobe-finned Fish (Sarcopterygii)

    • Fish with fleshy, lobed fins; ancestors of tetrapods.

    • Coelacanth (Actinistia): Living fossil with a unique lineage.

    • Lungfish (Dipnoi): Can breathe air using lungs and survive in low-oxygen water.

  • Tetrapod

    • Vertebrates that have four limbs, including amphibians, reptiles, birds, and mammals.

  • Derived Characteristics of Tetrapods

    • Adaptations for life on land include modifications of limbs and respiratory systems among others.

  • Tiktaalik

    • A fossil fish-tetrapod transition; exhibits features of both fish and early tetrapods, providing insights into evolutionary history.

  • Qikiqtania

    • Another transitional fossil with characteristics between fish and early tetrapods.

  • Amphibian

    • Class of tetrapods (e.g., frogs, salamanders) typically requiring moist environments for reproduction.

    • Moist Skin Lungs: Amphibians breathe through both lungs and their skin.

  • Tadpole

    • The larval form of amphibians, usually aquatic and herbivorous.

  • Non-amniotic Egg

    • Eggs that must remain moist and are laid in water, common in amphibians.

  • Salamander (Urodela)

    • A type of amphibian characterized by a slender body and long tail.

  • Frog (Anura)

    • A class of amphibians with a short body and long hind legs suitable for jumping.

  • Caecillian (Apoda)

    • Limbless amphibians that resemble worms or snakes.

  • Amniote

    • A clade of animals that lay eggs with specialized membranes, enabling reproduction in terrestrial environments.

    • Advantage of Amniote Egg: Allows for reproduction in dry habitats, minimizing the risk of desiccation.

  • Reptiles

    • A diverse group of amniotes characterized by scales and the ability to lay amniotic eggs.

  • Squamates

    • Includes snakes and lizards; characterized by their distinctive scale patterns.

  • Birds

    • Feathers, endothermic (warm-blooded), and modifications for flight distinguish birds.

  • Ectothermic vs. Endothermic

    • Ectothermic: Cold-blooded; rely on external sources for body heat.

    • Endothermic: Warm-blooded; ability to regulate body temperature internally.

  • Scales

    • Protective layers on the skin of reptiles, providing waterproof properties.

  • Diapsid Skull

    • A skull type with two temporal fenestrae; characteristic of reptiles excluding turtles.

  • Turtles

    • Unique reptiles characterized by a hard shell made of bony plates.

    • Turtle Shell: Composed of a carapace (upper) and plastron (lower).

  • Crocodilians

    • A group of reptiles that includes crocodiles and alligators, known for their semi-aquatic adaptations.

  • Dinosaurs

    • Dominant terrestrial reptiles during the Mesozoic era, leading to birds.

    • Theropod: A group of bipedal dinosaurs that are the ancestors of modern birds.

    • Pterosaurus: Flying reptiles closely related to dinosaurs.

  • Exaptation

    • A feature that evolved for one purpose but later adapted for different uses, such as feathers in birds.

  • Archaeopteryx

    • A transitional fossil showcasing both dinosaur and avian characteristics, critical for understanding the evolution of flight.

  • Flight Adaptations

    • Features developed for enabling flight, such as lightweight bones, feathers, and specialized muscles.

  • Homeothermic

    • Refers to the ability to maintain a constant internal body temperature.

  • Snake Adaptations

    • Various anatomical adaptations allowing for diverse ecological niches, including limbless locomotion and special feeding mechanisms.

  • Mammals

    • A class of endothermic vertebrates characterized by hair and mammary glands.

  • Synapsid Skull

    • A skull type with one temporal fenestra; ancestors of mammals.

    • Mammary Glands: Glands that produce milk to nourish offspring.

    • Hair: Provides insulation and is a characteristic feature of mammals.

    • Fat: Important for insulation and energy storage in mammals.

    • Kidneys: Specialized organs for excretion and osmoregulation in terrestrial environments.

    • Parental Care: Behaviors ensuring the survival of offspring; common in mammals.

    • Middle Ear: Unique structure allowing for better hearing in mammals.

  • Mammals in the Permian, Triassic, Jurassic, and Cretaceous

    • Evolutionary history of mammals revealing their development and diversification through geological eras.

  • Monotreme

    • Egg-laying mammals, examples include the echidna and platypus.

  • Echidna and Platypus

    • Unique among mammals due to their reproductive methods, highlighting early mammalian characteristics.

  • Marsupials

    • Mammals that give birth to relatively undeveloped young which continue to develop in a pouch (marsupium).

  • Placenta

    • An organ that develops in the uterus during pregnancy; supports nutrient and gas exchange between the mother and fetus.

  • Marsupium

    • A pouch-like structure in marsupials for carrying and nursing young.

  • Eutherians

    • Also known as placental mammals; give birth to fully developed young after a longer gestation period.