Bio 2 Vertebrates & Invertebrates

What are the 2 invertebrate clades without HOX genes?

Ctenophora & Porifera

Why do Ctenophora & Porifera have no HOX genes?

They are the oldest type of invertebrates and considered basal lines

What determines an animal's body plan?

Homeobox Genes aka HOX genes

In an animal's zygote cleavage how many mitotic divisions occur?

3

In an animals zygote cleavage how many blastomeres are made?

8

Diploblastic

2 Germs Layers: Ectoderm & Endoderm

Triploblastic

3 Germ Layers: Ectoderm, Mesoderm, Endoderm

Ectoderm

Outer most germ layer that covers surface of the animal

Endoderm

Innermost germ layer that forms the digestive track

Mesoderm

Middle germ layer that develops into muscles, veins, and other structures in animals

Which invertebrates lack true tissues (aka an ectoderm, mesoderm, & endoderm)?

Placozoa & Porifera

How many tissue types are present in placozoa?

4

How many tissue types are present in porifera?

12

Which invertebrate types exhibit radial symmetry?

Cnidarians & Ctenophores

What are the types of triploblasts?

pseudocoelomates, eucoelomates, & acoelomates

Pseudocoelomates

Triploblastic animals with a coelom that is lined partly with the ectoderm

Eucoelomates

Triploblastic animals with a coelom that is completely surrounded by the mesoderm

Acoelomates

Triploblastic animals with no coelom & a mesoderm filled completely with tissue

Which triploblastic type has no body cavity?

Acoelomates

Archenteron

the primitive gastric cavity of an embryo / beginning of the gut

Protostome

Blastopore becomes mouth

Deuterostome

Blastopore becomes the anus

Which is considered more primitive? Protostomes or Deuterostomes?

Protosomes

Protostome Invertebrates

Arthropoda, Mollusca, & Annelida

Deuterostomes Invertebrates

Echinoderms & Chordates

Exoskeleton

Hard covering / shell that protects an animal's body as well as acts as an attachment site for muscles

Apodemes

Ingrowths / sites of muscle attachment

What is the main disadvantage of an exoskeleton?

Extremely heavy & limits movement & size of animals with it

Endoskeleton

An internal support structure of cartilage or bone

Which better facilitates movement? An exoskeleton or endoskeleton?

Endoskeleton

Endothermic Animals

The use of a metabolism to maintain temperature and homeostasis

Types of Endothermic Animals

Homeothermic & Poikilothermic

Homeothermic Animals

Maintains constant temperature

Poikilothermic Animals

Temperature fluctuates depending on the environment / uses environment to maintain constant temperature

Ectothermic Animals

Does not need to maintain temperature or homeostasis via metabolism

What are the 2 main examples of animals who are both poikilothermic & homeothermic?

Lions & Bats (both situationally dependent)

Hibernation

Sleeping during extreme cold / coldest part of the day

Estivation

Sleep during drought & extreme heat / hottest part of the day

Torpor

Decreased activity & metabolism (usually on a daily basis) to conserve energy during the hottest / coldest part of the day

Types of Asexual Reproduction in Animals

Binary Fission, Budding, Fragmentation, & Parthenogenesis

Binary Fission

An organism splits into 2 equally sized organisms

Budding

An adult produces an outgrowth that separates & grows separately

Fragmentation

When a part of an adult animal is broken off and regenerates to form a new organism

Parthenogenesis

Adult female combines 2 eggs to produce new organism

Which form of asexual reproduction is the most common in invertebrates?

Parthenogenesis

Protogyny

The changing of sex from female to male

Protandry

The changing of sex from male to female

Types of Sexual Reproduction

Monoecious, External Fertilization, & Internal Fertilization

Monoecious Reproduction

Male and female reproductive organelles present in a single individual

External Fertilization

Eggs fertilized by sperm outside of the female's body

Types of External Fertilization

Broadcast Spawning & Courtship Spawning

Broadcast Spawning

Environmentally triggered reproduction in which gametes released into the water

Courtship Spawning

Behavior / location triggered reproduction

Internal Fertilization

Eggs fertilized by sperm inside of the female's body

Which form of reproduction in invertebrates is mostly in aquatic environments?

External

Which type of fertilization resulting in large numbers of offspring with low survival?

External

Types of Internal Fertilization

Oviparous, Viviparous, & Ovoviviparous

Oviparous

Lays eggs that hatch outside of the mom

Viviparous

Live birth

Ovoviviparous

Eggs produced in the mother who later gives live birthed

What are the main animals in which ovoviviparous internal fertilizations occur?

Sharks, Reptiles, & Sea Horses

Spermatogenesis

Production of sperm in the testes

Spermatogonia

1 spermatogonium goes through mitosis to produce to diploid cells. 1 to continue the process & 1 to become the sperm

Oogenesis

Production of eggs in the ovaries

Invertebrate Monophyletic Groups

Porifera, Cnidaria, Mollusca, Annelida, Arthropoda, Echinodermata, Platyhelminthes, & Nematoda

Porifera contain what type of animal?

Sponges

Porifera Characteristics

No true tissue (12 cells), flagellated larvae, sessile adults, & sexual and asexual reproduction

Porifera Morphology

Asymmetrical cylinders, spongocoel, choanocyte cells, osculum, and no digestive, nervous, respiratory, or circulatory system

Spongocoel

Central cavity of a sponge responsible for replacing nervous, respiratory, & circulatory system

Which invertebrate group digests intracellularly?

Porifera

Cnidaria contains what types of animals?

Jelly Fish & Anemones

Cnidaria Characteristics

Radial, diploblastic, & cnidocytes with nematocysts

Cnidaria Morphology

specialized cells instead of organs, nerve cells but no system, incomplete digestive (singular opening)

Polp

Sessile Cnidaria Adults

Medusa

Motile Cnidaria Adults

Cnidocytes

Special stinging structures / tenticales

Nematocysts

Stinging organelles / cells / barbs

Classes of Cnidaria

Anthozoa, Scyphozoa, Cubozoa, & Hydrozoa

Anthozoa

Sessile polyps (coral, sea fans, anemones)

Scyphoza

Medusa jelly fish

Cubozoa

Box jelly fish

Hydrozoa

Sessile & Medusa, contains hydra and portuguese man o' war

Platyhelminthes contains what types of animals?

Flatworms

Platyhelminthes Characteristics

Bilateral, triploblastic acoelomates, simple cephalization, free living or parasites

Platyhelminthes Morphology

Incomplete digestive system, combo mouth anus, waste disposed through pores in epidermis, monoecious

Cephalization

Nerves and sensory organs condensed within the head of an organism

Mollusca contains what types of animals?

Snails, mussels, octopi, etc

Mollusca Characteristics

Bilateral, triploblastic eucoelomates, protosomes, muscular foot for locomotion

Mollusca Morphology

Respiration through gills & complete digestive system

Which group of invertebrates is 2nd greatest in number?

Mollusca

Why did some invertebrates in Mollusca not have a visible muscular foot?

It is an automorphic trait they retroactively lost. It developed in mussels to the structures used to open and close shells

Classes of Mollusca

Bivalvia, Gastropoda, Cephalopoda

Bivalia contains what Mollusca?

Oysters & Clams

Bivalia Traits & Morphology

Enclosed shell, filter feed with gills, lost foot, sexual broadcast to make larvae

Gastropoda contains what Mollusca?

Snails & Slugs

Gastropoda Traits & Morphology

Marine & Terrestrial, open circulatory, true cephalization, predators & herbivores, wasted handled with nephridia, varied sexual reproduction

Cephalopoda contains what Mollusca?

Nautiluses, Squid, Octopi, Cuttlefish

Cephalopoda Traits & Morphology

Carnivorous beaked predators, respiration through gills, closed circulation, sexual reproduction muscular foot developed into tentacles, water jet for locomotion

Annelida contains what types of animals?

Segmented Worms

Annelida Characteristics

bilateral, triploblastic eucoelmates, protostomes, marine & terrestrial, contains filter feeders, parasites & predators