BIOL 206: Form and Function in Animals Quiz

A body plan describes the general structure, arrangement of organ systems, and how functional parts interact within an organism.

Radial symmetry means the organism can be divided into identical halves by many planes passing through the central axis. Think of a pie or wheel.

Bilateral symmetry means the organism can be divided into two identical mirror images by a single plane down the midline. Think of a human.

Cephalization refers to the development of a distinct head region with concentrated sensory organs and a brain.

A coelom is a fluid-filled body cavity that surrounds and cushions the internal organs, allowing for more complex movement.

Acoelomates are animals that lack a coelom (body cavity).

Pseudocoelomates have a body cavity partially lined with mesodermally derived tissue. It's not a true coelom, but a fluid-filled space surrounding organs.

Coelomates have a body cavity completely lined with mesodermally derived tissue, providing a true coelom that houses organs and supports movement.

Triploblastic animals develop three germ layers during embryonic development: ectoderm, mesoderm, and endoderm.

The ectoderm is the outermost germ layer, forming the epidermis and nervous system.

The mesoderm is the middle germ layer, forming muscles, skeleton, connective tissues, and some organs.

The endoderm is the innermost germ layer, forming the gut tube and most other internal organs.

Totipotent cells can develop into all cell types of the organism, including new embryos.

Pluripotent cells can develop into most cell types but cannot form new embryos.

Multipotent cells are partially differentiated and can become several, related cell types.

Unipotent cells can only self-renew and become one specific cell type.

Segmentation is the division of the body into a series of repeating units, like segments. This allows for specialization of body parts and complex movement.

Appendages are movable extensions of the body that are under voluntary control. They enable locomotion and various other functions.

A hydrostatic skeleton uses fluid pressure within a body cavity and muscle contraction to provide locomotion.

An endoskeleton is a hard, internal support structure within an organism. Think of bones in vertebrates.

An exoskeleton is a hard, protective outer covering that provides support. Think of the shell of a crab or the cuticle of an insect.

Epithelial tissue is composed of sheets of tightly connected cells that create boundaries between the inside and outside of the body, lining organs and controlling material transport.

Connective tissue is composed of cells that secrete an extracellular matrix, providing support and structure to other tissues and organs. Examples include cartilage, bone, blood.

Nervous tissue transmits long-range signals throughout the body, coordinating movement, secretion, and responses to sensory information. It's composed of neurons and glia.

Muscle tissue generates force for body movement and movement of material within internal organs. It's composed of three types: skeletal, smooth, and cardiac.

Organs are structures composed of different tissues that work together to perform a specific function. Every organ is made up of all four tissue types.

Physiology is the study of how an organism functions, including energy acquisition, nutrient distribution, reproduction, and internal regulation.

Homeostasis is the maintenance of a stable internal environment within a narrow range, regardless of external changes. Think of it as keeping your body in a comfortable state.

The set point is the normal range of values for a particular controlled variable within the body. It's genetically determined.

Feedback is a regulatory mechanism where the output or end-product of a process affects the process itself. There are two main types: negative and positive.

Thermoregulation is the process of maintaining a stable internal body temperature, regardless of external temperature changes.

Homeotherms are animals that regulate their body temperature internally to stay within a narrow range, regardless of external conditions. Think of mammals and birds.

Poikilotherms are animals whose body temperature fluctuates with the environment. Think of reptiles and amphibians.

Endotherms generate heat internally from their own metabolism. Think of mammals and birds.

Ectotherms obtain heat from external sources like the sun or warm water. Think of reptiles and amphibians.

Countercurrent exchange is a mechanism where heat is transferred between fluids flowing in opposite directions. Think of it like a heat exchanger.