Animal Biology: Form, Function, Nutrition, and Feedback Mechanisms

What are the three subtopics of Animal Biology?

Animal Form and Function, Animal Nutrition and Transport, Feedback Mechanisms in Animals.

What is morphoanatomy?

The study of anatomical forms and structures with emphasis on characteristics useful in distinguishing species.

What is bilateral symmetry?

A body plan that divides an organism into mirror image halves.

What is radial symmetry?

A body plan where an organism can be divided into similar halves by passing a plane at any angle along a central axis.

What is asymmetry in animals?

When an organism is not identical on both sides of a central line; it is unsymmetrical.

What are the three main parts of a sponge?

Ostia, osculum, and spongocoel.

What is a spongocoel?

The large, central cavity of sponges where water enters through ostia and exits through the osculum.

What are spicules?

Small needlelike or sharp-pointed structures that make up the skeleton of a sponge.

What characterizes Class Sclerospongiae?

Soft body covered by a skeleton.

What distinguishes Class Demospongiae?

It is the most diverse class of sponges, with spicules made of spongin or silica.

What is unique about Class Hexactinellida?

Commonly known as glass sponges, with spicules made of silica.

What are the main characteristics of Phylum Cnidaria?

Includes 10,000 species, found exclusively in aquatic environments, and exhibits radial symmetry.

What are the two life stages of Cnidarians?

The polyp form and the medusa form.

What are cnidocytes?

Specialized cells in Cnidarians, also known as 'stinging cells', used to stun and capture prey.

What are the three major worm phyla?

Phylum Platyhelminthes (flatworms), Phylum Nematoda (roundworms), Phylum Annelida (segmented worms).

What is a defining feature of Phylum Platyhelminthes?

They have a flattened body and may be free-living or parasitic.

What is the body structure of Phylum Nematoda?

Long, smooth, unsegmented bodies that are cylindrical and tapered at both ends.

What is a characteristic of Phylum Annelida?

They have segmented bodies both internally and externally, with a complete digestive system.

What are the main characteristics of Phylum Mollusca?

Soft, unsegmented bodies with a strong muscular foot; shells can be external or internal.

What is the defining feature of Phylum Echinodermata?

Body covered with spiny surfaces and an internal skeleton, using tube feet for movement.

What distinguishes Phylum Arthropoda?

It is the largest phylum in Animalia, including insects, crustaceans, and arachnids.

What are the three main parts of an insect's body?

Head, thorax, and abdomen.

What are the characteristics of Phylum Chordata?

Includes a single hollow nerve cord, notochord, pharyngeal slits, postanal tail, and segmentation.

What animals are included in Class Chondrichthyes?

Cartilaginous fish, including sharks and rays.

What defines Class Osteichthyes?

Bony fish, including typical marine and freshwater fish.

What animals are classified under Class Amphibia?

Includes salamanders, newts, frogs, toads, and caecilians.

What are the defining characteristics of amphibians?

Moist, scaleless skin; cold-blooded; undergo metamorphosis.

Name some examples of amphibians.

Salamanders, newts, frogs, toads, caecilians.

What is the primary characteristic of reptiles?

Cold-blooded; can regulate body temperature to match the environment.

What type of skin do reptiles have?

Scaly skin, developed from surface cells filled with keratin.

What are the common characteristics of birds?

Feathers, wings, lightweight skeleton, endothermic, lungs with air sacs, beak.

What are the shared characteristics of mammals?

Mammary glands, hair, jaw and ear bones, 4-chambered heart, diaphragm, complex brain functions.

What is asexual reproduction?

Reproduction where individuals are exact clones of the parent with identical genetic makeup.

What is sexual reproduction?

Reproduction involving the combination of gametes to form genetically unique offspring.

What are the types of asexual reproduction?

Regeneration, budding, parthenogenesis.

What is regeneration in asexual reproduction?

Production of new tissues to replace missing or damaged parts, involving mitosis and differentiation.

Describe budding in asexual reproduction.

Formation of a new individual from an outgrowth on the parent's body; common in Hydra.

What is parthenogenesis?

Development of an activated unfertilized egg into an organism, as seen in some insects and reptiles.

What is the difference between dioecious and monoecious organisms?

Dioecious have male and female reproductive organs in separate individuals; monoecious have both in one individual.

What is self-fertilization?

Fertilization involving the union of egg and sperm from the same individual.

What is cross-fertilization?

Fertilization involving gametes produced by separate individuals.

What is protandry in animal reproductive development?

A reproductive strategy where an individual starts as male and can change to female.

What is protogyny in animal reproductive development?

A reproductive strategy where an individual starts as female and can change to male.

What is indirect development in animals?

Development involving one or more intermediate larval forms before reaching adulthood.

What is direct development in animals?

Offspring hatch or are born in miniature adult form, with no metamorphosis.

What are gonads?

Sex organs that produce hormones regulating the development of gametes and secondary sex characteristics.

What is spermatogenesis?

The process of producing spermatozoa from primordial germ cells in the testes.

What is oogenesis?

The process of producing oocytes from primordial germ cells in the ovaries.

What is the function of the nervous system?

To respond quickly to environmental changes by gathering, processing, and transmitting information.

What is the structure of the nervous system in Hydra?

Nerve nets are diffused throughout the body to control contraction of the gastrovascular cavity.

What is cephalization?

The development of a central nervous system and brain in more complex organisms.

What are the two regions of the nervous system in annelids and arthropods?

Central Nervous System (CNS) and Peripheral Nervous System (PNS).

What are the two divisions of the autonomic nervous system?

Sympathetic nervous system (stress response) and parasympathetic nervous system (resting state).

What is the role of the immune system?

To defend organisms from pathogens such as viruses, bacteria, fungi, and cancer cells.

What are the two major lines of defense in the immune system?

Innate immunity and acquired/adaptive immunity.

What is innate immunity?

A nonspecific response to a broad range of microbes.

What are the two lines of defense under innate immunity?

First line: skin and mucous membranes; Second line: phagocytosis by phagocytes.

What role does the skin play in innate immunity?

Acts as a barrier to invading pathogens and has an acidic pH (~3.5) that kills microorganisms.

What are phagocytes?

Cells responsible for engulfing and destroying pathogens through phagocytosis.

What triggers the inflammatory response?

The presence of pathogens that escape the first and second lines of innate immunity.

What is the function of histamine in the inflammatory response?

It dilates blood vessels to allow more blood flow to the affected area.

What is acquired immunity?

A specific defense mechanism against pathogens provided by lymphocytes.

What are the two types of cells involved in acquired immunity?

B cells and T cells.

What do B cells do?

Produce antibodies that attach to antigens.

What are the three types of T cells?

Killer T cells, Helper T cells, and Suppressor T cells.

What is the role of Killer T cells?

They attack infected cells by injecting chemicals to destroy pathogens.

What is the function of Helper T cells?

They assist B cells in antibody production.

What is the purpose of Suppressor T cells?

They stop B and T cells after the infection has been cleared.

What is a hydrostatic skeleton?

A fluid-filled compartment within the body that supports organs, found in soft-bodied animals.

What is an exoskeleton?

An external hard encasement on the surface of an organism, providing defense and support.

What is chitin?

A polysaccharide that makes up a significant portion of exoskeletons in arthropods.

What is an endoskeleton?

A skeletal structure located within the soft tissues of organisms, providing support and protection.

What are the main functions of the human skeleton?

Support the body, store minerals and lipids, produce blood cells, protect internal organs, and allow movement.

What are the two divisions of the vertebrate skeletal system?

Axial skeleton and appendicular skeleton.

What bones make up the axial skeleton?

The skull, vertebral column, and rib cage (total of 80 bones).

What bones are included in the appendicular skeleton?

Shoulders, limb bones, pectoral girdle, and pelvic girdle (total of 126 bones).

What is skeletal muscle tissue?

Muscle that attaches to the skeletal system, controls movement, and is under voluntary control.

What is the morphology of skeletal myocytes?

Elongated, tubular, striated, and contain multiple peripheral nuclei.

How do skeletal muscles assist in movement?

By contracting and pulling on bones to create movement.

What is the role of the lymphatic system in immunity?

It stores B cells and memory B cells, and is activated during an immune response.

What happens during phagocytosis?

Phagocytes engulf pathogens, forming a vacuole that fuses with lysosomes to destroy the pathogen.

What is the significance of the acidic environment of sweat, tears, and saliva?

It helps kill bacteria and provides a chemical defense against pathogens.

Where is cardiac muscle tissue found?

Only in the heart.

What is the primary function of cardiac muscle tissue?

To pump blood throughout the body and maintain blood pressure.

How is cardiac muscle classified in terms of control?

It is involuntary and not consciously controlled.

What unique structure differentiates cardiac muscle from skeletal muscle?

Intercalated discs.

How do cardiac myocytes compare in size and nucleus count to skeletal muscle cells?

Cardiac myocytes are shorter and typically contain one or two centrally located nuclei.

What role does smooth muscle tissue play in the body?

It regulates flow in various organ systems, such as aiding food movement through the digestive system via peristalsis.

How is smooth muscle tissue characterized?

It is non-striated and involuntary.

What is the shape and nucleus arrangement of smooth muscle myocytes?

Spindle-shaped with a single centrally located nucleus.

What are the two classifications of animals based on their digestive systems?

Invertebrates and vertebrates.

What is the function of the digestive system in animals?

To break down large, complex molecules into smaller, absorbable molecules.

What type of digestive system do animals with gastrovascular cavities have?

A single opening that serves as both mouth and anus.

Name an example of an animal with a gastrovascular cavity.

Hydra or any member of Cnidaria.

What is an alimentary canal?

A pathway that receives food through the mouth and eliminates waste through the anus.

Which invertebrates have an alimentary canal?

Earthworms (Annelida) and insects (Arthropoda).

What are the four types of digestive systems found in vertebrates?

Monogastric, avian, ruminant, and pseudo-ruminant.

What is a monogastric digestive system?

A system that consists of a single stomach chamber.

What is the process of ingestion?

The process by which animals take in food using their mouth.

What role does saliva play in digestion?

It contains enzymes that help break down carbohydrates in food.