Biology Chapter 40: Physical Laws and Animal Form - Prof. Thomas Abbott, Study notes of Biology

Download Biology Chapter 40: Physical Laws and Animal Form - Prof. Thomas Abbott and more Study notes Biology in PDF only on Docsity! Biology Chapter 40 Concept 40.1- Physical Laws and the Environment Constrain Animal Size and Shape Anatomy: study of biological form of organism Physiology: study of biological functions an organism performs Physical Laws and Animal Form:  Physical requirements constrain what natural selection can invent, including shape and size  For example, sharks, penguins, and dolphins are fast swimmers because of their streamlined body form. o These similar shapes are an example of convergent evolution. Convergence occurs because natural selection shapes similar adaptations when diverse organisms face the same environmental challenge Exchange with the Environment:  Animal’s size and shape have a direct effect on how the animal exchanges energy and materials with its surroundings  Animal’s body plan must allow all of its living cells to be bathed in aqueous medium for integrity of plasma membrane o Exchange occurs through diffusion o Surface area to volume ration plays an important role in diffusion o Single cell has sufficient SA to volume o Animal cell has numerous cells Shape is important  Flat shapes help with surface area, but do not provide complex internal organization  Complex bodies have distinct benefits: o Specialized outer covering to protect against predators o Large muscles for rapid movement o Internal digestive organs to break down food, controlling energy release o Cells immediate environment is in body fluid, allowing internal control for stability Concept 40.2: Animal form and function are correlated at all levels of organization Living things exhibit hierarchical levels of organization, each with emergent properties. Tissue structure and Function:  Tissues - Groups of cells with a common structure and function. Different types have different structures suited for function. Ex. Weaves, extracellular matrix  Four Categories: Epithelial, Connective, Muscle, Nervous  Epithelial: o Epithelial Tissue - Occurs in sheets of tightly packed cells, covers outside of body and lines organs and cavities within body. Functions as barrier against injury, microbes, and fluid loss. o Glandular Tissue- Absorb or secrete chemical solutions, for example, ones that line the lumen form mucous membrane.  Mucous Membrane - Secret mucus that lubricates surface and keeps moist o Two criteria for classifying epithelial: Number of cell layers and shape of cells  Simple Epithelial: Single layer of cells  Stratified Epithelial: Multiple tiers of cells  Pseudostratified: Single layered but appears stratified because cells vary in length  Cuboidal shape: Dice like  Columnar - Like bricks standing on end  Squamous : Floor like tiles  Connective Tissue: o Connective Tissue: Functions mainly to bind and support other tissues. Sparse population of cells scattered through extracellular matrix. o Connective Fibers: Made of protein, and have three kinds  Collagenous fibers, elastic fibers, and reticular fibers  Collagenous- Made of collagen, most abundant protein. Nonelastic, does not tear easily.  Elastic Fibers: Long threads made of protein called elastic. Rubbery quality that complements collagen fiber.  Reticular Fiber : Think and branched. Composed of collagen and continuous with collagenous fibers, form tightly woven fabric that joins tissues  Vertebrates : Major tissue include loose connective tissue, adipose tissue, fibrous connective, cartilage, bone, and blood  Loose Connective- Binds epithelial to tissue and holds organs in place  Cartilage: Strong flexible support material  Fibrous: Found in tendons which attach muscle to bone, ligaments  Adipose- Fat for insulation  Blood- Composed of blood cells and cell fragments in plasma  Bone: Mineralized and forms skeleton o Fibroblasts: secrete the protein ingredients of the extracellular fibers o Macrophages : Amoeboid cells that engulf foreign particles.  Muscle Tissue: o Composed of long cells called muscle fibers that are capable of contracting. Large units of myofibrils made of actin and myosin. o Vertebrates have skeletal muscle, cardiac muscle, and smooth muscle  Skeletal muscle: Striated muscle responsible for voluntary movement  Smooth Muscle: Involuntary movement  Cardiac muscle: Contraction of heart  Nervous Tissue: o Senses stimuli and transmits signal in the form of nerve impulses from one part to another. o Functional unit is neuron, or nerve cell.