Unit 2: How does animal structure enable life functions? Anatomy is the study of the biological form of an organism Physiology is the study of the biological functions an organism performs Form and function are closely correlated

Hierarchical Organization of Animal Bodies Cells form a functional animal body through emergent properties that arise from levels of structural and functional organization Cells are organized into – Tissues, groups of cells with similar appearance and common function – Organs, different types of tissues organized into functional units – Organ systems, groups of organs that work together

How do living life forms (active) compare with non-living life forms (inactive)?

Life Processes Circulation (Intra- and Extracellular Transport) Regulation (Endocrine and Nervous) Reproduction (asexual and sexual) Nutrition (Ingestion, Digestion, Absorption, Egestion) Excretion (Metabolic) Respiration (aerobic and/or anaerobic) Growth (Mitosis) Synthesis (Biochemistry)

Objective: For each life process, describe the anatomical structures that enable physiological function throughout the animal kingdom. How have these structures evolved throughout evolutionary history? Evaluate examples of disruptions to homeostasis for each life process.

Table 32.1

PoriferaCnidaria Ctenophora Phoronida Ectoprocta Brachiopoda Echinodermata Chordata Platyhelminthes Mollusca Annelida Arthropoda Rotifera Nemertea Nematoda Radiata Deuterostomia Protostomia Bilateria Eumetazoa Metazoa Ancestral colonial flagellate Parazoa

Kingdom Animalia contains the Metazoans. How are the metazoans different from other organisms (i.e.. plants, fungi, protists, bacteria)

In evolutionary history, life began in the oceans with simple, organic, free- living cells. Organisms became more complex as life transitioned from water to land. Comparative anatomy and physiology explores the evolution of tissue differentiation, organs, and organ systems over time.

Characteristics of the Animal Kingdom Tissue Organization (1) – True tissue or absence of true tissue Embryonic Development (2) – Diploblastic or Triploblastic – Protostome or Deuterostome Symmetry – Asymmetrical, Radial, Bilateral Cephalization (3) Body Plan – Sac plan, Tube-in-a-tube Coelom (4) – Acoelomate, Pseudocoelomate, Coelomate Segmentation (5) – Segmented or Non-segmented

Characteristics of the Animal Kingdom Tissue Organization (1) – True tissue or absence of true tissue Embryonic Development (2) – Diploblastic or Triploblastic – Protostome or Deuterostome Symmetry – Asymmetrical, Radial, Bilateral Cephalization (3) Body Plan – Sac plan, Tube-in-a-tube Coelom (4) – Acoelomate, Pseudocoelomate, Coelomate Segmentation (5) – Segmented or Non-segmented

How is a zygote formed?

Embryonic development

Embryonic Germ Layers Diploblastic- 2 layers -ectoderm and endoderm -no mesoderm -ex. Cnidarians, Porifera (sponges) Triploblastic- 3 layers -ectoderm, mesoderm and endoderm -all animals with bilateral symmetry

Why is germ layer differentiation an evolutionary advantage for animals?

Archenteron Blastopore Mesoderm Coelom Blastopore Mesoderm Coelom ectoderm -outer layer -forms animal’s outer covering, in some phyla central nervous system endoderm -inner layer -forms lining of digestive tract, in vertebrates forms liver, lungs mesoderm -between ectoderm/endoderm in triploblast -forms muscles between digestive tract and animal’s outer covering Embryonic Germ Layers

During gastrulation, the blastopore is a structure to pay attention to.

Embryonic development

If the blastopore becomes a mouth, then the animal is characterized as a protostome. If the blastopore becomes the opening of an anus, the animal is characterized as a deuterostome.

Embryonic Cleavage: Determinate (Protostomes) vs. Indeterminate (Deuterostome) e.g. In humans, the first few divisions are indeterminate. If cells in the embryo separate within the first divisions, the result is identical twins.

Characteristics of the Animal Kingdom Tissue Organization (1) – True tissue or absence of true tissue Embryonic Development (2) – Diploblastic or Triploblastic – Protostome or Deuterostome Symmetry – Asymmetrical, Radial, Bilateral Cephalization (3) Body Plan – Sac plan, Tube-in-a-tube Coelom (4) – Acoelomate, Pseudocoelomate, Coelomate Segmentation (5) – Segmented or Non-segmented

Label objects as having radial, bilateral, or asymmetrical lines of symmetry.

Body symmetry and degrees of cephalization co-evolved in the animal kingdom (see Echninoderms and see if this statement holds).

Characteristics of the Animal Kingdom Tissue Organization (1) – True tissue or absence of true tissue Embryonic Development (2) – Diploblastic or Triploblastic – Protostome or Deuterostome Symmetry – Asymmetrical, Radial, Bilateral Cephalization (3) Body Plan – Sac plan, Tube-in-a-tube Coelom (4) – Acoelomate, Pseudocoelomate, Coelomate Segmentation (5) – Segmented or Non-segmented

Why do the highlighted organisms demonstrate higher degrees of cephalization compared to the un- highlighted?

Characteristics of the Animal Kingdom Tissue Organization (1) – True tissue or absence of true tissue Embryonic Development (2) – Diploblastic or Triploblastic – Protostome or Deuterostome Symmetry – Asymmetrical, Radial, Bilateral Cephalization (3) Body Plan – Sac plan, Tube-in-a-tube Coelom (4) – Acoelomate, Pseudocoelomate, Coelomate Segmentation (5) – Segmented or Non-segmented

Alimentary Canal Two-way digestive planOne-way digestive plan

Characteristics of the Animal Kingdom Tissue Organization (1) – True tissue or absence of true tissue Embryonic Development (2) – Diploblastic or Triploblastic – Protostome or Deuterostome Symmetry – Asymmetrical, Radial, Bilateral Cephalization (3) Body Plan – Sac plan, Tube-in-a-tube Coelom (4) – Acoelomate, Pseudocoelomate, Coelomate Segmentation (5) – Segmented or Non-segmented

A coelom is a fluid-filled body cavity. What is the advantage of having a cavity with fluid, in regards to organ system organization?

How is a pseudocoelomate different from a coelomate?

Characteristics of the Animal Kingdom Tissue Organization (1) – True tissue or absence of true tissue Embryonic Development (2) – Diploblastic or Triploblastic – Protostome or Deuterostome Symmetry – Asymmetrical, Radial, Bilateral Cephalization (3) Body Plan – Sac plan, Tube-in-a-tube Coelom (4) – Acoelomate, Pseudocoelomate, Coelomate Segmentation (5) – Segmented or Non-segmented

Define segmentation using these examples.

Justify why we would expect to see evidence of segmentation in organisms with higher degrees of cephalization?

Summary: How has the animal kingdom evolved over time, with respect to complexity of systems and habitat?