Unit 4 Study Guide (bio1108)

Chemoheterotrophs

Organisms that obtain energy from organic compounds.

Choanoflagellates

Closest living relatives of animals.

Porifera

Phylum of sponges, lacking symmetry and mobility.

Cnidaria

Phylum including jellyfish and sea anemones.They are characterized by the presence of specialized cells called cnidocytes. Have radial symmetry and are typically aquatic organisms.

Bilateria

Animals with bilateral symmetry and organ systems.

Radial Symmetry

Multiple planes of symmetry, suited for slow movement.

Bilateral Symmetry

Single plane of symmetry, allows directional movement.

Cephalization

Concentration of nervous system at the head. (e.g. brain, eyes)

Segmented Body Plan

Body structure divided into repeated sections.

Blastula

Early embryonic stage forming a sphere of cells (blastomeres).

Diploblastic

Embryos with two germ layers: ectoderm and endoderm.

Triploblastic

Embryos with three germ layers: ectoderm, mesoderm, endoderm.

Choanocytes

Cells in sponges that facilitate feeding by water flow.

Gastric Cavity

Digestive cavity with one opening in Cnidarians.

Protostomes

Blastopore develops into mouth during embryonic development.

Deuterostomes

Blastopore develops into anus during embryonic development.

Lophotrochozoans

Protostome subgroup with tentacle-lined feeding organs.

Ecdysozoans

Group of animals that molt their exoskeleton.

Arthropods

Joint-legged animals with segmented bodies.

Echinoderms

Deuterostome group including starfish and sea urchins.

Chordates

Animals with a notochord, dorsal nerve cord, and gill slits.

Mesophyll

Support cells in sponges maintaining structural integrity.

Spicules

Structural elements in sponges providing support.

Head region of segmented animals

Develops into feeding structures and specialized body regions.

Chordate characteristics

Pharynx, notochord, neural tube, tail

Pharynx in humans

Develops into face and neck structures.

Notochord in humans

Replaced by vertebral column during development.

Neural tube

Forms brain and spinal cord in vertebrates.

Tail in humans

Internally present as a reduced tailbone.

Vertebrate groups

Include jawless, cartilaginous, bony fishes, tetrapods.

Amniotic egg

Allows reproduction away from water environments.

Marsupials

Offspring born early, develop in a pouch.

Placental mammals

Develop placenta for nutrient transfer before birth.

Primate characteristics

Binocular vision, opposable thumbs, bipedalism, fingerprints.

Uniquely human traits

Bipedalism and increased cranial capacity.

Animal tissues

Four types: epithelial, connective, muscle, nervous.

Epithelial tissue

Lines body surfaces, controls movement in/out.

Connective tissue

Provides support, nutrients for epithelial, and extracellular matrix.

Muscle tissue

Cells contract for movement; types include skeletal.

Nervous tissue

Processes sensory information and sends signals.

Homeostasis

Regulation of internal environment through feedback mechanisms.

Stimulus

Change that triggers a response in an organism.

Sensor

Detects stimulus and communicates with effectors.

Effector

Produces response to restore homeostasis after stimulus.

Negative feedback

Opposes change to maintain stable internal conditions.

Macromolecules in diets

Animals consume carbohydrates, fats, and proteins.

Nutritional needs

Fuel, organic materials, and essential nutrients required.

Digestion in sponges

Intracellular digestion without a digestive system.

Cnidarian digestion

Simple system with one opening for food intake.

Bilaterian digestion

Extracellular digestion in specialized body compartments.

Surface area importance

Increased area enhances nutrient absorption efficiency.

Diffusion in animals

Key for gas exchange in organisms without lungs.

Diffusion

Process of gas exchange in respiration.

Ventilation

Movement of air/water past respiratory surfaces.

Respiratory surface

Specialized area for gas exchange.

Oxygen transport

Circulatory system carries O2 to tissues.

Mitochondria

Cell organelles where ATP is produced.

Gills

Aquatic structures for extracting O2 from water.

Gill arches

Support structures for gill filaments.

Gill filaments

Thin structures increasing surface area for gas exchange. (in fish)

Lamellae

Small plates on gill filaments enhancing surface area.

Countercurrent exchange

Opposing fluid flow maintaining concentration gradients.

Unidirectional airflow

Continuous air movement in bird lungs.

Air sacs

Storage areas for air in birds' respiratory system.

Tracheal tubes

Insect structures for direct air delivery to tissues.

Spiracles

Openings in insects for air entry.

Hemolymph

Insect fluid analogous to blood.

Alveoli

Tiny lung sacs maximizing gas exchange surface area.

Homeostasis in breathing

Regulating oxygen and CO2 levels during activity.

Hemoglobin

Protein in blood binding O2 for transport.

Myoglobin

Muscle protein storing oxygen for energy.

Arteries

Blood vessels carrying oxygenated blood from heart.

Veins

Blood vessels returning deoxygenated blood to heart.

Capillary bed

Network where arteries and veins exchange substances.

Heart structure comparison

Differences in heart anatomy across animal groups.

Fish Heart

2 chambers; pumps deoxygenated blood to gills.

Amphibian Heart

3 chambers; mixes oxygenated and deoxygenated blood.

Mammalian Heart

4 chambers; separates oxygenated and deoxygenated blood.

Leukocytes

White blood cells involved in immune response.

Innate Immune System

First defense; nonspecific immune response.

Adaptive Immune System

Second defense; specific immune response.

Endocrine System

Uses hormones for long-term regulation.

Nervous System

Uses nerve impulses for quick responses.

Sponges

Lack nerve cells; simplest animal group.

Cnidarians

Have a decentralized nervous system.

Fight-or-Flight Response

Body's reaction to stressors for survival.

Sympathetic Nervous System

Activates fight-or-flight response.

Hormonal Conservation

Basic hormone structures maintained through evolution.

Sexual Reproduction

Combines genetic material from two parents.

Asexual Reproduction

Single parent produces genetically identical offspring.

Parthenogenesis

Asexual reproduction from unfertilized eggs.

Meiosis

Cell division reducing chromosome number by half.

Fertilization

Sperm and egg fusion creates a zygote.

Gametes

Haploid reproductive cells; sperm and egg.

Sperm

Male gamete; small and motile.

Egg

Female gamete; larger and stationary.

Zygote

Single cell formed post-fertilization.

Embryo

Early developmental stage post-zygote.