Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion...
-
Upload
felix-trevor-robinson -
Category
Documents
-
view
220 -
download
0
Transcript of Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion...
![Page 1: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/1.jpg)
Introduction to Animals
![Page 2: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/2.jpg)
To be an animal means
1. Multicellular – humans have ~ 50 - 100 trillion cells
2. Ingestive heterotroph
3. Lacking a cell wall
4. Specialization of cells (except Porifera)
5. May involve movement & sexual reproduction (formation of a zygote)
![Page 3: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/3.jpg)
Phylogenetic tree of animal kingdomPhylogenetic tree of animal kingdom
• Based on:– Body symmetry– Patterns of embryo development– Comparing fossils– rRNA
![Page 4: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/4.jpg)
Symmetry
• Overall pattern of structure– Asymmetric - No symmetry as with the Porifera
– Radial symmetry – even cut along a diameter. Echinodermata and Cnidaria
– Bilateral symmetry – even cut along a central plane. Worms, Arthropods, Mollusks, Echinoderms, and Vertebrates
![Page 5: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/5.jpg)
Trends in Animal Evolution
• As you go up the phylogenetic tree, you will see a greater tendency towards bilateral symmetry.
• Also a concentration of nerves (sensory organs) towards the front of the organisms known as cephalization
![Page 6: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/6.jpg)
Body views
1. Dorsal – top/back
2. Ventral – belly/bottom
3. Anterior – front/head
4. Posterior – tail/rear
Ventral (bottom)
Dorsal (top)
Posterior (tail end)
Anterior (front)
![Page 7: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/7.jpg)
CleavageCleavage• A series of cell divisions that occurs
immediately following fertilization– Mitosis occurs but cells do not grow in size.
![Page 8: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/8.jpg)
Stages in CleavageStages in Cleavage
Morula
Solid ball stage
Zygote
Blastula
Hollow ball stage
Gastrula
Indented ball stage
During gastrulation, an indentation occurs.
A multi-layer embryo is formed with 3 germ layers
Blastopore – opening of indentation
![Page 9: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/9.jpg)
• Protostome– Blastopore developes into the oral opening
(mouth)– Mollusks, arthropods and annelids
• Deuterostomes– Blastopore developes into anus– Echinoderms and Chordates (that’s us)
![Page 10: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/10.jpg)
![Page 11: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/11.jpg)
Germ Layers
• Fundamental tissue types found in embryos of animals (but not sponges)
• Gives rise to every body feature, organs & tissues
• 2 germ layers in Cnidaria & 3 in all others– Endoderm – forms throat, gills, lungs and
digestive tract (with pancreas and liver)– Ectoderm – forms outer skin, hair, nails and
nervous system– Mesoderm – skeleton, muscles, inner skin layer,
circulatory system and lining of the body cavity
![Page 12: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/12.jpg)
![Page 13: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/13.jpg)
Body Cavities • Acoelomates – Body cavity is absent. As in Flatworms .
Endoderm is connected solidly to mesodermal tissue• Pseudocoelomates – Body cavity contains three distinct
layers but endoderm is not connected to mesoderm. Free floating in fluid. Found in roundworms.
• Coelomates – True body cavity. Mesoderm lines body cavity while supporting endodermic. Mollusks, annelids,
arthropods, chordates and echinoderms
![Page 14: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/14.jpg)
Systems through the Phyla
Circulatory systems•
Closed Circulatory System– One in which blood is always contained within a
vessel. Heart serves as a pump. Found in annelids, chordates
Open Circulatory System– Pumps blood into spaces around the body tissues.
From there the blood makes its way back to vessels that will carry it back to the heart, or possibly to holes in the heart itself. Found in Arthropods and some mollusks
![Page 15: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/15.jpg)
SkeletonsExoskeleton – Rigid, outer
covering protecting soft internal tissue. Found in Arthropods and mollusks. Needs to be shed (molt) as animal grows.
Endoskeleton – Internal skeleton. Best for larger organism. Found in echinoderms and vertebrates. Grows as animal grows.
![Page 16: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/16.jpg)
Reproduction:• Asexually by budding
(Porifera, Cnidarians) or regeneration (Porifera, Planaria, Sea stars)
• Sexually – Hermaphroditic – contains
both sexes (but not self fertilization necessarily). Think of your earthworm
– Separate sexes – as you go up the phylogenetic tree
![Page 17: Introduction to Animals. To be an animal means 1.Multicellular – humans have ~ 50 - 100 trillion cells 2.Ingestive heterotroph 3.Lacking a cell wall 4.Specialization.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649de45503460f94adb629/html5/thumbnails/17.jpg)
DevelopmentIncomplete
metamorphosis – Direct development – young animal is born or hatched looking like adult but smaller. No larval stage. Mantids, Grasshoppers, us
Complete metamorphosis – Indirect development – intermediate larval stages appearing different from adult.Butterfly, flies, moths