basic principles of animal form and function - quia · 2018-03-22 · biology, seventh edition neil...

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

PowerPoint Lectures for Biology, Seventh Edition

Neil Campbell and Jane Reece

Lectures by Chris Romero

Chapter 40

Basic Principles of Animal Form and Function


Big Ideas •  Physical laws and environment constrain size and shape.

•  Energy from food sustains form and function.

•  Thermoregulation contributes to homeostasis and involves anatomy, physiology, and behavior.


•  All animals face a similar set of problems (how to nourish themselves, obtain oxygen, get rid of waste, etc.)

•  Form and function are closely correlated.

•  Natural selection will favor individuals with the “best” traits.


Physical Laws and the Environment •  Physical laws and the need to

exchange materials with the environment place limits on the range of animal forms.

•  Ex: shape of fast-swimming fish and aquatic animals


•  Organisms with more complex body plans have highly folded internal surfaces specialized for exchanging materials.

More complex body plans…


•  Tissues – groups of cells with a common structure and function

Levels of Organization


•  Epithelial –  covers the outside

of body –  lines organs and

cavities



•  Connective –  binds and

supports other tissues

–  major types: loose connective, adipose (fat), fibrous connective, cartilage, bone and blood



•  Muscle –  3 types: skeletal,

smooth, and cardiac

•  Nervous



•  Different tissues are organized into organs.


Organs and Organ Systems •  Organs make up organ systems.


•  All organisms require energy for growth, repair, physiological processes, regulation, and reproduction.

•  Bioenergetics – the flow of energy through an animal

•  Energy ultimately limits the animal’s behavior, growth, and reproduction.

Bioenergetics


Energy Sources and Allocation •  Food is used to:

–  make ATP, which powers cellular work

–  biosynthesize (grow, repair, store fat, produce gametes)


•  Metabolic rate – amount of energy an animal uses in a unit of time

Quantifying Energy Use


•  Birds and mammals

–  are warmed mostly by heat generated by metabolism

–  typically have higher metabolic rates

Endotherms vs. Ectotherms

•  Amphibians and reptiles

–  gain their heat mostly from external sources

–  have lower metabolic rates


Size and Metabolic Rate •  Metabolic rate per gram is inversely related to body size

among similar animals.

•  Why?


•  The basal metabolic rate (BMR) – metabolic rate of an endotherm at rest

•  Maximum possible metabolic rate is inversely related to the duration of the activity.

Activity and Metabolic Rate


Homeostatic Control •  What is homeostasis?

•  Interstitial fluid

–  the internal environment of vertebrates

–  can be very different from the external environment

•  3 functional components: a receptor (detects levels), a control center (creates set point, assess), and an effector (create changes to set system back to set point)


•  NEGATIVE feedback – buildup of the end product shuts the system off

•  POSITIVE feedback – buildup of the end product amplifies the change


Thermoregulation •  Thermoregulation – process by which animals maintain an

internal temperature within a tolerable range


Thermoregulation in Animals

River otter (endotherm)

Largemouth bass (ectotherm)

Ambient (environmental) temperature (°C)

Bod

y te

mpe

ratu

re (°

C)

40

30

20

10

10 20 30 40 0


•  Endothermy

–  more energetically expensive than ectothermy

–  but buffers animals’ internal temperatures against external fluctuations

–  enables the animals to maintain a high level of aerobic metabolism


Modes of Heat Exchange •  Organisms exchange heat by four physical processes

Figure 40.13


Modes of Heat Exchange •  Organisms exchange

heat by four physical processes.

•  Many endotherms and ectotherms can alter blood flow.

•  Vasodilation – blood flow in the skin increases, facilitating heat loss

•  Vasoconstriction – blood flow in the skin decreases, lowering heat loss

Figure 40.13


Behavioral Responses


Torpor and Hibernation

•  Torpor – short-termed hibernation

•  Hibernation – long-termed

•  Estivation – summer topor

•  Daily torpor

basic principles of animal form and function - quia · 2018-03-22 · biology, seventh edition neil...

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