Animal Diversity and Homeostasis

Vocabulary flashcards covering key concepts from the lecture notes on animal diversity, tissue types, homeostasis, and more.

Unique Characteristics of Animals

Multicellular, heterotrophic eukaryotes that lack cell walls and have organized tissues.

Closest Living Relatives of Animals

Choanoflagellates, unicellular or colonial flagellates, are the closest living relatives.

Porifera

Simplest animals with a porous body plan; lack true tissues, organs, and a nervous system.

Cnidaria

Diploblastic animals with radial symmetry, a nerve net, and specialized stinging cells.

Bilateria

Triploblastic animals with bilateral symmetry allowing for cephalization and active movement.

Radial Symmetry

Body parts arranged around a central axis, common in organisms like cnidarians.

Bilateral Symmetry

Distinct left and right sides, allowing for cephalization and defined head region.

Cephalization

Concentration of sensory organs at the anterior end of an animal, aiding in navigation.

Diploblastic

Organisms developing two germ layers: ectoderm and endoderm, e.g., cnidarians.

Triploblastic

Organisms developing three germ layers: ectoderm, mesoderm, and endoderm.

Blastula

An early embryonic stage consisting of a hollow ball of cells.

Choanocytes

Collar cells in sponges that create water flow for feeding and digestion.

Cnidocytes

Specialized stinging cells in cnidarians for capturing prey.

Gastric Cavity

A gastrovascular cavity in cnidarians acting as both mouth and anus.

Protostomes

Group in which the blastopore becomes the mouth during embryological development.

Deuterostomes

Group in which the blastopore becomes the anus, with the mouth forming secondarily.

Lophotrochozoans

A clade within protostomes that includes mollusks and annelids.

Ecdysozoans

Animals that must molt their exoskeleton as they grow, including arthropods.

Notochord

A flexible rod present during the development of chordates; replaced by the vertebral column in humans.

Dorsal Hollow Nerve Cord

The nerve cord that develops into the spinal cord and brain in chordates.

Pharyngeal Slits/Pouches

Structures in human embryos that contribute to head and neck structures.

Amniotic Egg

An egg that contains membranes providing a self-contained aquatic environment for the embryo.

Marsupials

Mammals that give birth to undeveloped young that continue to develop in a pouch.

Placental Mammals

Mammals with a complex placenta facilitating longer gestation periods.

Epithelial Tissue

Tissue that covers body surfaces, involved in protection and absorption.

Connective Tissue

Tissue providing structural support and binding tissues together.

Muscle Tissue

Tissue facilitating movement; includes skeletal, cardiac, and smooth muscle.

Nervous Tissue

Tissue that transmits electrical signals for communication and control.

Stimulus

Any change in the environment that triggers a physiological response.

Sensor

A receptor detecting the stimulus.

Effector

Organ or tissue acting to counteract a change in homeostasis.

Response

Action taken by the effector to return the system to its set point.

Negative Feedback

Control mechanism that reverses deviation from a set point to maintain stability.

Endotherms

Organisms that generate their own heat, such as mammals.

Ectotherms

Organisms that rely on environmental heat sources, like reptiles.

Macromolecules

Large molecules consisting of carbohydrates, proteins, and lipids essential for nutrition.

Gas Exchange

Process of oxygen uptake and carbon dioxide removal in animals.

Diffusion

Movement of gases across cell membranes or respiratory surfaces.

Countercurrent Exchange

Blood flows in the opposite direction to air or water over gills, enhancing gas exchange.

Hemoglobin

Oxygen-carrying protein in red blood cells transporting oxygen to tissues.

Arteries vs. Veins

Arteries carry blood away from the heart; veins return blood to the heart.

Leukocytes

White blood cells crucial for immune response.

Innate Immune System

Non-specific and immediate response to pathogens.

Adaptive Immune System

Delayed and specific response involving B and T cells.

Meiosis

Cell division that produces haploid gametes and fosters genetic variation.

Fertilization

Union of sperm and egg to form a zygote.

Genetic Variation

Variability in traits resulting from processes like crossing over during meiosis.

Parthenogenesis

A form of asexual reproduction where an egg develops without fertilization.