Upload
william-nash
View
213
Download
1
Embed Size (px)
Citation preview
Chapter 25-27By: Stacy Mckinney
Andrew Strawther
Mikayla Brown
Jared Rudd
Chapter 25 Animals
Animals are eukaryotic, multicellular, heterotrophic organisms.
The first animals evolved in water.Digestion for animals takes place in a
internal cavity.Animals have special cells that help it
seek out food and mates, it also allows them to protect themselves from predators.
Chapter 25 Animals
The process of a baby forming inside a animal is the same inside of a human.
Chapter 26 Section 1&2
Sponges are very simple animals that live permanently attached to a location in the water , they are sessile as adults.
Most sponges are hermaphrodites (an be male or female) fertilization is external sponges release sperm that floats till it finds another sponge. Sponges can break off and attach to rocks and grow as a clone of the first sponge.
Chapter 26 Section 2 Cnidarians are a diverse group of aquatic
animals, more than 9000 species are part of the phylum cnidarian, and all species are aquatic , cnidarians are widespread in marine habitats and less common in fresh water.
Cnidarians come in two forms polyp, medusa.
Polyps- stationary sponges for life
Medusa-freemoving , true jelly fish are meduas.
Classes of cnidarians
AnthozoaScxphozaHydrozoacubozoa
Unsegmented Worms
CHAPTER 26, section 3 and 4
FLATWORMS
Belongs to the phylum (plat=flat)
3 classes:
-turbellaria
-trematoda
-cestoda
CHARACTERISTICS
Acoelomates – (no body cavities) They have bilateral symmetry Respiration through skin
Class Turbellaria
spade shaped head and 2 eyespotsScavengersFlame cells remove wasteHermaphrodites (have male and
female parts) Reproduce by regeneration
Class Trematoda
Parasitic flukes Have suckers on both ends of the
bodyCan live inside or outside of hostHermaphrodites Have complex life cycles
LIFE CYCLES
EggMiracidium(free living in water)Sporocyst (in snail)Redia (in snail) Cercaria (free living in water/snail)Metacercaria (in second intermediate
host) adult
Class Cestoda
ParasiticTapewormsLong bodiesAbsorbs nutrients from hosthermaphrodites
ROUNDWORMS
Roundworms
belong to phylum NematodaSlender bodies that taper on both
ends Have mouth and anusCan be free living or parasitic
Pinworms live in human intestines
Trichinosis is a disease from eating infected pork
Rotifers
known as wheel animalsFree swimming, transparentFreshwater and marineHave a ring of cilia around mouth that
brings in foodFeed on unicellular algae and bacteriaHave a muscular organ that chops food
Chapter 27
What is a mollusk?
-slugs, snails, squids, and some animals that live in shells in the ocean or on the beachMollusks have bilateral symmetry, a
coelom, a digestive tract with two openings, a muscular foot, and a mantle
Chapter 27
Mollusks use a rasping structure called radula to obtain food
-radula can be used to drill, scrape, grate, or cut out foodThey reproduce sexually
Chapter 27
Have simple nervous systems that control their movement and behavior
Have well-developed circulatory system that usually includes a two or three-chambered heart
Chapter 27
Most mollusks have an open circulatory system; the blood moves through vessels and into open spaces around the body organs
Some move nutrients and oxygen through a closed circulatory system; blood moves through the body enclosed entirely in a series of blood vessels
Most have respiratory structures called gills
Chapter 27
Three classes
-Gastropoda; one-shelled
-Bivalvia; two-shelled
-Cephalopoda; head-footed
Chapter 27
What is a segmented worm?
-leeches, bristleworms, earth wormsBilaterally symmetrical and have
coelom and two body openings
Chapter 27
Food is taken in by the mouthHave simple nervous systems,
organs have become modified for sensing the environment
Have closed circulatory systems
Chapter 27
Earthworms and leeches are hermaphnodites
Bristleworms reproduce sexually
Chapter 27
Three classes
-Oligochaeta; earthworms
-Polychaeta; brislteworms
-Hirudinea; leeches