Download DNA Technology - Loyalsock Township School District

Ch. 32
Nutritional Mode
Heterotrophic by Ingestion
• Eat other living organisms
• Eating nonliving organic material
Enzymes
• Used within the body to digest the
food ingested
Cell Structure and Specialization
• Eukaryotes
• Multicellular
• Extracellular matrix
– Collagen
• Muscle and nervous cells
unique to animals
– Organized into tissue
– Movement
– Conduct impulses
Reproduction and Development
• Sexually reproducing
–Diploid organism is dominant
• Gametes
–Produced by meiosis; haploid
–Sperm small and flagellated
–Egg large and nonmotile
• Fertilization results in a zygote
Reproduction and Development
Early Embryonic development in animals
Gastrula
Gastrulation
results in 3
tissue layers:
1. Ectoderm
2. Mesoderm
3. Endoderm
Reproduction and Development
Some animals have larval stages
• Sexually immature form of a n animal that is
morphologically different from the adult
• Eat different foods; live in different habitats
Metamorphosis
• Developmental transformation that turns the animal
into a juvenile that resembles an adult but is not yet
sexually mature
Reproduction and Development
Homeoboxes
• Developmental genes that
regulate the expression of
other genes
• Found in all animals
Hox genes
• Important role in embryo
development
• Arose from duplication of
homeobox genes
History of Animals…More Than Half
a Billion Years
Neoproterozoic Era (1 billion – 542 mya)
• Ediacaran Biota
Paleozoic Era (542-251 mya)
• Cambrian explosion
Mesozoic Era (251-65.5 mya)
Cenozoic Era (65.5 mya – present)
Animals can be Characterized by
“Body Plans”
Body Plan
• Particular set of morphological and
developmental traits, integrated into
a functional whole
Symmetry
Absent
• sponges
Radial
• Has a top and bottom
• No left or right/front or back
Bilateral
• Two axes  front to back; top to
bottom
• Dorsal/ventral; anterior/posterior
• Cephalization
– The concentration of sensory
equipment at the anterior end and a
central nervous system in the head
Tissues
Metazoans
• Lack true tissues
• Phylum Porifera (sponges)
– early branch of animal kingdom
Eumetazoans
• Contain true tissues
• Germ layers
Tissues
Diploblastic
• Ectoderm
– Germ layering covering the surface of the embryo
– Gives rise to outer covering and central nervous
system
• Endoderm
– Innermost germ layer
– Lines the archenteron during gastrulation
– Gives rise to lining of the digestive tract/cavity as
well as liver and lungs of vertebrates
– Found in liver, pancreas, thyroid, parathyroid,
thymus
Tissues
Triploblastic
• Ectoderm, Ectoderm
Mesoderm
•
Forms the muscles and most organs
located between the digestive tract and
outer covering of the animal
Located between endoderm and ectoderm
•
Can be found in
•
Connective tissues
•
Circulatory system, muscles and
bones
•
Notochord, Dermis of skin
•
Kidneys, Gonads
Body Cavities
A fluid or air filled space
located between the
digestive tract and the
outer body wall
Cushions body organs,
prevents internal injury,
may act as a
hydroskeleton, allows
organs to move
independently
• Acoelomate
• Pseudocoelomate
• Coelomate
Acoelomate
No body cavity develops between
the digestive tract and the
outer body wall
Gastrovascular cavity
• Single opening for
digestive system and
circulation
• No vascular system exists
Outer wall filled with cells
• No specialized
compartment
Ex – Phylum Platyhelminthes
(flatworms)
Pseudocoelomate
• Not really “pseudo”
b/c coelom is
functional
• Pseudocoelom is not
completely lined with
tissue derived from
the mesoderm
• Ex – Phylum
Nematoda
(roundworms) and
Phylum Rotifera
Coelomate
• Fluid-filled body cavity completely
lined with cells from the mesoderm
(coelom) that separates digestive tract
from the outer body wall
• Mesoderm completely lines the body
cavity
• Two openings for digestive system
• Mesenteries suspend internal organs
• Fluid-filled cavities
– cushion organs
– Internal organs can grow and move
– Serve as a hydrostatic skeleton
• Annelids, Mollusks, Arthropods,
Echinoderms, and Chordates
Coelomate Split
Protostomes
• coelom formed from
cell masses
• mollusks, annelids,
arthropods
Coelomate Split
Deuterostomes
• coelom formed from
digestive tube
(archenteron)
• echinoderms and
chordates
Cleavage
Spiral Cleavage
• Protostome development
• Planes of cell division are
diagonal to the vertical axis of
the embryo
• Determinate cleavage
Radial Cleavage
• Deuterostome development
• Planes are parallel or
perpendicular to the vertical axis
of the embryo
• Interdeterminate cleavage
Body Plans
Coelom Formation
• Archenteron
– Blind pouch formed from an
embryo’s developing digestive
tube
Fate of the Blastopore
• Indentation that during
gastrulation leads to the
formation of the archenteron
Animal Phylogeny…Molecular Data
1. All animals share a
common ancestor
2. Sponges are basal
animals
3. Eumetazoa is a clade of
animals with true tissues
4. Most animal phyla
belong to the clade
Bilateria
5. Chordates and some
other phyla belong to
the clade Deuterostomia