Chapter 17 Evolution Of Animals Part 1 Flashcards
In 2003, anthropologists discovers bones of some highly unusual people from where?
Dating back to when?
Indonesian island of Flores
Dating back to 18,000 years
What made the unusual people on the Indonesian islands different?
Shorter,
Would stand about waist high to a woman
Skeptical scientists suggested that the bones were from _________ with diseases that caused ___________
Homo sapiens
Skeletal malformations
This amazing diversity arose through hundreds of millions of years of evolution as ________ shaped animal adaptations to earths many environments.
Natural Selection
Animals are what?
Eukaryotic
Multicellular
Heterotropic
Organisms that obtain nutrients by eating and are able to digest food with their bodies
Animals
Animal cells _____ that provide strong support in bodies of plants and fungi
Lack cell wallls
Most animals have
Muscle and nerve cells
These cells are used for movement
Muscle cells
These cells are used to control the muscles
Nerve cells
Most animals are ___ and reproduce __
Diploid and reproduce sexually
In the life cycle of a sea star, the ____ undergoes a major change of body form called ____
Larva
Metamorphosis
Scientist hypothesize that animals evolved from a
Colonial flagellates protist
What suggests a much earlier origin for animals?
Molecular data
Cambrian explosion may have been ignited by
Complex predator-pre relationships
Atmospheric oxygen
A set of master control genes
Genetic framework
Historically biologist have categorized animals by ___ general features of body structures
Body plan
Allowed evolutionary biologists to modify and refine groups
Genetic data
Lack true tissues
Sponges
Refers To animals that are identical all around the central axis
Radical symmetry
Exist where there is only one way to split the animal into equal halves
Bilateral symmetry
What helped lead to more complex animals?
Evolution of body cavities
A fluid filled space separating the digestive tract from outer body wall
Body cavity
Animals without backbones
Invertebrates
95% of the animal kingdom
Invertebrates
Stationary animals
Sponges
Sponges evolved very early from
colonial protists
The body of a sponge resembles
Sac perforated with holes
Move water through the pores into a central cavity and then out of the sponge through a larger opening
Choanocyte cells
Characterized by the presence of body tissues, radical symmetry, tentacles with stinging cells
Cnidarians
The basic body plan of a cnidarian is a sac with a central digestive compartment
Gastrovascular cavity
The body plan of Cnidarians has two variations
Stationary ____ and floating ___
Polyp and Medusa
Cnidarians are
Carnivores
Cnidarians are carnivores that use ___ arranges in a ring ____ to capture prey and push into the ____,where digestion begins
Tentacles
Around the mouth
Gastrovascular cavity
Stinging cells are
Cnidocytes
Cnidocytes our stinging cells function
Defense
Prey capture
Soft body animals usually protected by a hard shell
Molluscs
Many molluscs feed by extending a file like organ called
Radula
To scrape up food
Radula
Molluscs are mostly
Marine animals
Molluscs have a similar body plan with three main parts
Muscular foot
Visceral mass
Mantle
Molluscs usually used for movement
Muscular foot
Molluscs have this which contains most of the internal organs
Visceral mass
Molluscs have a fold of tissue that secretes the s present
Mantle
There are 3 main groups of molluscs
Gastropods
Bivalves
Cephalopods
Includes snails
Gastropods
Includes clams, oysters, mussels, and scallops
Bivalves
She’ll divided into two halves hundred together
Bivalves
Head+foot
Cephalopods
Include squids and octopus and are all marine animals
Cephalopods
Their bodies are fast and while
Cephalopods
Large brains and sophisticated sense organs
Cephalopods
Few species with large, heavy shells, but in most the shell is small and internal
Cephalopods
Flat worms phylum
Playyhelminthes
Simplest animals with bilateral symmetry
Flatworms
Ribbon like
Flatworms
Range from about 1mm to 20mm
Flatworms
Flatworms include forms that are
Parasites