23-1 Chapter 23 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes

23-1

Chapter 23

Lecture Outline

See PowerPoint Image Slides

for all figures and tables pre-inserted into

PowerPoint without notes.

Homework for Ch 22(In case you missed it when I wrote it on the board ) This does need to be turned in..

Concept Review 2, 3, 5, 6, 7, 8,10,12,14,15

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.23-2

Things to know from Chapter 23(Note: you do not have to turn this in)

What are characteristics shared by all animals? How are invertebrates and vertebrates different? What is difference between body forms with asymmetry, radial

symmetry, and bilateral symmetry? What are poikilotherms (ectotherms)? homeotherms

(endotherms)? How so plankton and nekton organisms differ? What are differences between polyp stage and medusa stage? List 3 characteristics shared by chordates. List problems chordates have had to overcome to adapt to a

terrestrial environment.


Things to know cont...

Characteristics of amphibians. Need water for what? Characteristics of reptiles. Importance of shelled egg in

evolution of reptile. Characteristic of mammals. 3 types of mammals. Differences

between the 3 types. Characteristics of arthropods. Note that they are the most

successful group. Characteristics of Echinodermata.



What is an animal?

Eukaryotic Multicellular

– Have specialized cells– Many have sensory cells that detect changes in

the environment. Lack cell walls Heterotrophic Most can move Most reproduce sexually

invertebrates

http://www.youtube.com/watch?v=hIXu9ZjUtsY


Mimic octopus

http://www.youtube.com/watch?v=ygh1-ul6E94



The Evolution of Animals

Early animals were all aquatic.– The first animals were likely small organisms that

floated/swam in the ocean or worms that lived on the ocean floor.

– These animals didn’t need to Deal with rapid or extreme environmental changes Deal with dehydration Expend energy to keep cells in osmotic balance

Terrestrial animals appeared relatively recently.– Arthropods and vertebrates have been the most successful.

99.9% of all animals are invertebrates.– Invertebrates lack a backbone.– Vertebrates have a backbone.


Animal Evolution

Figure 23.2


Temperature Regulation

Body temperature impacts the rate of metabolic activity.

Poikilotherms– Body temperature varies with environmental temperature– Metabolic rate decreases as temperature decreases– Also called ectotherms– Regulate body temperature behaviorally (sunning, moving)– Insects, worms, reptiles


Temperature Regulation

Homeotherms– Maintain a constant body temperature– Body temperature usually higher than

environmental temperature– Have high metabolic rates– Have higher energy needs than poikilotherms– Also called endotherms


Symmetry

Asymmetry– No pattern to individual parts– Only occurs in sponges

Radial symmetry– Body constructed across a central axis– Dividing the body in any plane along that axis results in two

identical parts– These animals do not have a “head”– Starfish, jellyfish

Bilateral symmetry– Both sides of a single plane are mirror images– These animals have a head– Move head-first (cephalization)


Marine Lifestyles: Zooplankton

A mixture of different kinds of small animals Drift with currents Feed on phytoplankton and other

zooplankton 70% are crustaceans

– Copepods, krill, etc.


Marine Lifestyles: Nekton

Includes many kinds of aquatic animals that can swim against the current– Go where they want to

Carnivores – Feed on plankton or other nekton

Jellyfish, squid, cuttlefish, shrimp, sharks, bony fish, turtles, sea snakes, aquatic birds and mammals


Marine Lifestyles: Benthic Animals

Bottom-dwelling animals Includes

– Segmented worms, clams, snails, lobsters, crabs, shrimp, starfish, sea urchins, several kinds of fish

Two types– Those that move to find food– Filter feeders

Attached to objects Are sessile Create currents with cilia or use appendages to draw food to

them


Marine Lifestyles: Benthic animals

Reproduction is difficult for sessile animals because they cannot move.– Sperm swim to the eggs.– Fertilized egg develops into mobile larva

Enables sessile animals to disperse Uses a different source of food from adults to minimize

competition


Primitive Marine Animals: Porifera

Similar to colonial protozoa Have two layers of cells

– All cells come in contact with the environment.– Each individual cell gets its nutrition directly from the water.

Adults are sessile (non-motile). Most are asymmetrical. Have spicules in a jelly-like material

– Spicules are made of calcium carbonate, silicon dioxide, or protein. Reproduce asexually by fragmentation or budding Reproduce sexually by external fertilization

– Sperm and egg unite in the water– Fertilized egg develops into free-swimming ciliated larva


Sponge Structure and Function

Figure 23.10


Primitive Marine Animals: Cnidaria

Jellyfish, corals, and sea anemones Have two layers of cells

– Jelly-like material in between cell layers Show radial symmetry Have a single opening that leads to digestive

cavity– Opening surrounded by tentacles

Contain specialized cells called nematocytes that can sting and paralyze

The cells that produce nematocytes are called cnidocytes.


Phylum Cnidaria

Figure 23.11


Cnidaria

Exhibit alternation of generations

– Have both sexual and asexual reproduction

– Medusa is the free-swimming adult stage that reproduces sexually.

– Polyp is a sessile larval stage that reproduces asexually.

Figure 23.12 in a column, small ok


Arthropoda

Most successful type of animals Have exoskeletons made of chitin

– Must shed to grow Have segmented bodies

– Segments are highly modified.– Most segments have paired appendages.– Body and appendages are segmented.

Have well-developed nervous, muscular, digestive, respiratory, circulatory, and reproductive systems


Types of Arthropods

Crustaceans– All aquatic– Omnivores

Millipedes and centipedes– Long bodies with many legs

Arachnids– Spiders, mites, and ticks

Insects– Have a head, thorax, and abdomen– Have 3 pairs of legs– Most have wings


Echinodermata

Spines on surface Radial symmetry Marine habitats only Tube feet Water vascular systems


Types of Echinoderms

Starfish– Some are carnivores

that eat clams

Sea cucumbers– Sausage-shaped

organisms– Lie on the bottom or

burrow in mud– Some are detrivores,

others are filter-feeders.

Crinoids– Sessile and stalked– Have five arms– Called sea lilies– Filter feeders

Brittlestars Sea urchins


Chordata

Have a hollow nerve cord down the back of the body

Have a flexible rod just beneath the nerve cord– Called the notochord

Have a tail that extends beyond the anus Have a pharynx Most are vertebrates

– Notochord only present during embryonic stage


Adaptations to Terrestrial Life

Animals that live on land have to overcome certain problems.– A moist membrane for gas exchange– Means of support and locomotion on land– Methods to conserve water– Means of reproduction and embryonic

development that doesn’t require water– Methods to survive rapid and extreme climate

changes


Amphibians

Lungs– Allow for the exchange of oxygen and carbon

dioxide from the air– Amphibians also breathe through their skin.

Skin must remain moist

External reproduction in water Frogs and salamanders


Amphibians

Moist skin, no scales, external fertilization typical, metamorphosis common, lungs in adult form, three-chambered heart


Reptiles

Have internal lungs Have waterproof skin Have water-conserving

kidneys Reproduce via internal

fertilization– Fertilized egg is encased

in an amniotic egg– Protects the young from

dehydration and injury Young need water to

develop.

Figure 23.34


Birds

Skin, lungs, and kidneys reduce water loss Reproduction involves internal fertilization.

– Produces a shelled amniotic egg

Are homeothermic and have feathers– Have high metabolic rates– Feathers insulate and enable flight.– Must incubate eggs

Flight allows – Movement with less expenditure of energy– Quick escape from predators– Ability to cross barriers


Mammals

Homeotherms – High, constant body temperature– High metabolic rate

Have waterproof skin, water-conserving lungs and kidneys

Have hair as insulation Provide milk to their young


Types of Mammals

Monotremes– Egg-laying mammals– Young lap milk from mother’s fur

Marsupials– Internal development of young– Young complete development in mother’s pouch

In pouch, young drink milk from nipple

Placental– Internal development of young

Stay in mother longer Embryo attached to uterus via a placenta

– Young are born in a more advanced stage Still rely on mother’s milk

Documents

23-1 Chapter 23 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes