Midterm 3 Flashcards
Opistokonts
Holozoa (Animal-Like), Holomycota (Fungus-like)
Or just Animals and Fungi.
Fungi are:
Heterotrophs
Decomposers
Choanoflagellates
Closest relatives of animals.
Animals are:
Monophyletic
Multicellular
Heterotrophic
The Major Animal Groups
Porifera | Sponges.
Ctenophores | “comb jellies”.
Cnidaria | Jellies, Corals, and others.
Bilateral | Insects, Vertebrates, Worms, Crustaceans, Mollusks.
Plaquazoa | NA
Cambrian Explosion
From 505-542 mya
Most major groups/forms of animals appear at the same time in the fossil record, which makes it hard to identify key adaptations over time.
Porifera
“Sponges”
Porocytes: Holes
Choanocytes: Generate current with flagella
Osculum: Opening
Amoebocyte: Digest food INTRAcellularly
50k species
Asymmetric
Ctenophora
“Comb Jellies”
Colloblasts: Sticky cells on tentacles to capture prey.
Move by beating cilia.
About 186 species.
Rotationally symmetric
Cnidaria
Polyp Stage: Sedentary and asexual
Medusa Stage: Mobile and sexual
Hydrostatic Skeleton
- Class Scyphozoa
- Class Anthozoa
Cell Division in Animals
- Cleavage: Partitions the cytoplasm of one large cell into many smaller cells called ‘blastomeres’.
- Blastula: Early state of mitotic division, forming 128+ cells that form a hollow sphere.
- Gastrulation
Gastrulation
Infolding of the blastula, producing a 2-3 layered embryo, with an opening to the outside.
1. Endoderm
2. Mesoderm
3. Ectoderm
Diploblasts
Develop two germ layers.
Radially symmetric.
Triploblasts
Develop three germ layers.
Bilaterally symmetric.
Class Scyphozoa (phylum cnidaria)
Jellies, Sea Nettles
Marine
Lack Polyp
Class Anthozoa (phylum cnidaria)
Sea Anemones, Most Corals
Marine, sessile
Only sexual polyp stage.
Deuterostomes
‘Anus first’
Echinoderms (sea stars, sea anemones)
Chordates:
- Vertebrates
5-3-2
5: major animal groups
- Porifera
- Ctenophores
- Placazoa
- Cnidaria
- Bilateral
3: major bilateral groups
- Deuterostomes
- Protostomes : Lophotrochozoa
- Protostomes : Ecdysozoa
2: groups in each.
- Ecdysozoa: Arthropods | Nematodes
- Lophotrochozoa: Molluscs | Plathyhilmethes
- Deuterostomes: Echinoderms | Vertebrates
Placozoa
4 species
Asymmetric
Bilateria
Protostomes:
- Ecdysozoa
- Lophotrochozoa
Deuterostomes:
Ecdysozoa
Arthropods
Nematodes
Lophotrochozoa
Mollusca
Platyhelmenthis
Mollusk Features
Visceral Mass
Mantle
Foot
Radula
Platsyhelminthes Features
Ganglia
Pharynx
Eye Spots
Ventral nerve cords
gastrovascular cavity
Nematoda
Roundworms
Arthropoda Features
Segmentation
Hard Exoskeleton
Jointed Appendates
Coelom
Body cavity that forms during early development
True Coelom
Coelom develops in the middle of the mesoderm
Pseudocoelom
Coelom develops between germ layers
Acoelom
No Coelom
Functions of Coelomic Cavity
Circulation:
- Digestion / Excretion
Reproduction:
- Can allow more gametes to be exchanged at once.
Support:
- hydrostatic skeleton
Hemimetabolous
Partial-Trasforation / Metamorphasis
Holometabolous
Complete Metamophasis
Types of parental care
None
Maternal
Biparental
Paternal
Alloparental care
- Relatives
- Mon-relatives
Diet Types
Carnivore
Herbivore
Omnivore
Parasite
Types of Movement
Active
Passive
- for marine organisms carried by currents
Cessile
- attached to the substrate
Skeleton Types
Internal
External
Hydrostatic
- cavities filled with water
Social Types
Solitary
Social
Division of labor
Eusocial
- queen societies where a single female monopolizes reproduction
Sexuality Types
Obligate sexuality
Obligate asexuality
Facultative sexuality
- sex occurs once per year
- sex occurs once per cycle through a parasite’s host
- sex occurs when environmental conditions degrade
Types of Reproduction
Broadcast spawning
External fertilization
- male individual and female individual meet, deposit gametes
Internal fertilization
- fertilization takes place within the female body
Internal fertilization with viviparity
- egg hatches within the female
- has evolved many times
Types of Sex Distribution
Dioecious: separate sexes
Hermaphroditism
- both male and female sex functions in the same individual
- simultaneous: egg and sperm production
- sequential: egg first, then sperm later, or vice versa.
Are invertebrates monophyletic?
No
Vertebrates are within invertebrates.
Are diploblasts monophyletic?
No
Are worms monophyletic?
No
The ‘worm form’ has evolved many times.
Are animals monophyletic?
Yes
Animals have only evolved once, and don’t have any other distinct groups inside.
Are multicellular organisms monophyletic?
No
Multicellularity has evolved many times.
What is the major shared feature of Ecdysozoa?
Ecdysis, or molting.
What is the difference between protostomes and deuterostomes?
Protostomes: Mouth First
Deuterostomes: Anus First
Two examples of groups with hydrostatic skeletons.
- Cnidaria
- Nematodes
- Analids
Two examples of groups with exoskeletons.
- Hexapods
- Crustaceans
One example of a group with an internal skeleton.
Vertebrates
(Mammalia?)
Diploblasts vs. Triploblasts?
Diploblastic: 2 germ layers
Triploblastic: 3 germ layers
Which major group is triploblastic?
Bilateria
Which major group accounts for the most animal species?
Bilateria
Which group of bilateria accounts for the most species?
Arthropoda
Which group of arthropods accounts for the most species?
Hexopods
What are the three major groups of multicellular organisms?
Plants, Animals, and Fungi
Which kingdom contains 2/3 of the major multicellular groups?
Plants
Which multicellular group is primarily saprobes?
Fungi
Which multicellular group contains species with multinucleate cells?
Fungi
The closest living relative to multicellular animals?
Chaoanophlagellates
Four ways bilateral animals are unique?
Bilateral Symetrical
Segmentation
Triploblast
True Tissues
Which two major groups of animals lack true tissues?
Porifera
Placazoa
What is a Coelom and what is its significance?
A hollow, fluid-filled cavity that is found in many organisms.
What is the evidence of the benefits of holometabolous insects?
Prevents parental competition.