Theory Flashcards
What did Earth’s Atmosphere consist of:
- Water Vapor
- Hydrogen Gas
- Ammonia
- C02
- Methane
- limited free Oxygen
What was mixed in the Milley-Urey Experiment
Water, hydrogen, methane, and ammonia.
Result: 15% of the C mixture was converted into organic compounds such as: amino acids, urea, and fatty acids
Why couldn’t life start on earth again?
Because present atmosphere is strongly oxidizing. Molecules necessary for life can’t be synthesized outside of the cell: unstable in the presence of O2.
5 theories of Darwin
1) Perpetual Change
2) Common Descent
3) Multiplication of Species
4) Gradualism
5) Natural Selection
* First 3 are widely accepted
Difference between fragmentation and budding
Each fragment from fragmentation grows into new independent parts and regenerates unlike budding.
3 types of sexual reproduction
1) Bisexual reproduction
2) Hermaphroditism
3) Parthenogenesis
What is the evidence for common descent?
Developmental Homologies.
Describes the comparison of pharyngeal arches of four different embryos at the early stages of development.
What is Cleavage?
When the embryo divides repeatedly without growth (skips G-phase of mitosis). The zygote subdivides.
Zygote -> Blastula
Which pole of the egg has the most yolk?
The vegetal pole
4 types of Yolk Placement:
1) Isolecithal: Very little yolk, evenly distributed
2) Mesolecithal: moderate amount of yolk concentrated at vegetal pole.
3) Telolecithal: abundance of yolk deeply concentrated at the vegetal pole.
4) Centrolecithal: Large centrally located mass of yolk.
What developmental pattern is associated with large amount of yolk?
Direct development. Goes straight from embryo to mature adult.
EXPECTION IN MAMMALS
What yolk placement patterns are associated with Holoblastic cleavage patterns?
Isolecithal and Mesolecithal
What is the name of the process of which the blastula bends inwards?
Invagination
Which organisms have only 1 germ layer
Sponges
Which organisms have two germ layers (Diploblastic)
sea sponges, sea anemones, corals, and comb jellies
What is the first event in organogenesis
Formation of the nervous system (formed from the ectoderm)
What is the first functional organ
The heart (formed from the mesoderm)
What are the different ways to categorize metazoans?
1) Fate of Blastopore
2) Cleavage Patterns
3) Fate of Cells
4) Mesoderm Formation
How is the coelom formed during Schizocoely
Mesodermal cell division (mesoderm are formed first)
How does the coelom form during Enterocoely
Mesoderm and coelom form at the same time. Archenteron elongates and the sides push out outward and expand into a pouch-like coelomic compartment. Pouch-like compartment pinches off.
What body plan(s) does Enterocoely form
Only coelomate
Can cells grow when separated from mosaic development
No, they require positional information from neighbouring cells.
Conditional Specification is associated with that type of development
Regulative Development
How are species named?
Genus (first letter capitalized) + Species (all lower case)
What is the Hierarchy of Taxonomy
1) Domain
2) Kingdom
3) Phylum
4) Class
5) Order
6) Family
7) Genus
8) Species
What fall under the domain of Prokaryota
Bacteria and Archea (no nuclear membrane)
What are the 6 Kingdoms?
1) Animalia
2) Plantae
3) Fungi
4) Protista
5) Bacteria
6) Archea
What are Protozoa
Unicellular eukaryotes (used to be considered a Phylum, but no longer are). Paraphyletic group
Which organisms possess a trochophore larvae
Platyhelminthes, Annelida, Mollusca (Lophotrochozoan Protostomes)
Which organisms shed their cuticle as they grow
Nematoda and Arthropoda (Ecdysozoan Protostomes)
Where is the mouth formed in Protostomes
Where the blastopore was
What type of cleavage pattern do Deuterostomes exhibit
Radial cleavage (in most instances)
What type of development is seen in Lophotrochozoan Protostomes
Mosaic Development
How is the coelom formed in Deuterostomes
By enterocoely
Disadvantages of being unicellular
Limited size, Shorter life span, No division of labour
Modes of locomotion in Uni. Eukaryotes
Flagella (whiplike organelle)
Cilia (hair like organelle that moves particles along the cell surface)
What are cilia and flagella collectively referred as
Pseudopodia (locomotion and engulfing food)
How do Amoebas travel
using pseudopodia
How do Heterotrophs get energy
By consuming other life
What do Saprozoic feeders ingest
Food in soluble form (not visible)
What is the cell mouth in unicellular eukaryotes called
Cytostome
What is the site where indigestible matter is expelled called
Cytoproct
How do paramecium reproduce sexually
Bu conjugation (the exchange of chromosomal material via cytoplasmic bridges between bacteria).
How do micronuclei divide
Mitotically
What is amitotic cell division
When the nucleus and cytoplasm divide without forming a spindle or condensation of chromosomes
What does not occur inside an Intermediate host
Maturation and sexual reproduction
What is the difference between sporogony and schizogony
Schizogony (multiple fission): sporozoite (n) -> many merozoites (n)
Sporogony (special case of schizogony): Zygote (2n) -> Many sporozoites (n)
What makes up the cell wall in fungi
Chitin
What are some examples of Photoheterotrophs
purple and green non-sulfur bacteria
What type of digestion do fungi use
Extrecellular digestion
What type of symmetry do Porifera exhibit
Radial or no symmetry
What are ostia
Pores which allow the flow of water in Porifera
What are oscula
Water outlets
What are the three forms of porifera
Asconoid (flagellated spongocoel)
Syconoid (flagellated canals)
Leuconoid (flagellated chambers)
Where does the water flow to before reaching the radial canals in Porifera
Prosopyles
Where does the water flow to before reaching the spongocoel in Porifera
Apopyles
What are spongocoel
The large central cavity of sponges where water enters
What are Pinacocyte
Epithelial type cell (thin tissue forming the outer layer).
What are Choanocyte
Flagellated collar cells. Move water, collect food particles and consume via phagocytosis.
What are Archeocyte
Ameboid cells. Transport food and oxygen to other cells
What is the major structural protein for metazoans
Collagen
What is a form of collagen secreted by Class Demospongiae
Spongin
What is used to classify sponges (based on shape)
Spicules
What are the types of asexual reproduction in sponges
Fragmentation
Budding
Gemmulation
What do sperm and oocytes develop from
Choanocytes (sometimes archeocytes)
How do sponges carry the sperm from the choanocyte to the oocytes
Via the mesohyl
What does spherical symmetry aid in
floating and rolling
What exhibits radial symmetry
Sponges, jellyishes, and sea urchins
What exhibits biradial symmetry
com jellies (Ctenophora)
What does the posterior end display
The back side (tail end)
What does distal direction mean
parts further from the middle of the body
What is the habitat of cnidaria
mostly marine, some freshwater, no terrestial
What are the classes of Phylum Cnidaria
1) Hydrozoa (hydroids, fire corals)
2) Scyphozoa (true jellyfish)
3) Cubozoa (Box jellyfish)
4) Anthozoa (sea anemones and corals)
What are the 2 forms of Cnidaria
polyp (asexual or sexual, sessile or sedentary)
medusa (sexual, free moving)
What type of gut do Cnidarians have
“Blind gut” only one opening
What is a Cnida
Stinging organelle
What is the most common type of Cnida
Nematocyst
What is a Cnidocil
Triggers the nematocyst to fire
What classes exhibit both medusa and polyp stages
Hydrozoa
Scyphozoa
What class only exhibits a medusa stage
Cubozoa
What type of symmetry do Ctenophores exhibit
Biradial symmetry
What organism do Ctenophores form symbiotic relationship with
Anemones (protect anemone from getting eaten while anemonefish provide nitrogen to their hosts)
What is the outcome when zooxanthellae die
Coral begins to bleach (lose pigmentation and become brittle)
What are the 3 body plans seen in worms
Coelomate (body cavity develops entirely from the mesoderm)
Pseudocoelomate (internal body cavity surrounding the gut but not completely lined with the mesoderm)
Acoelomate (no coelom but digestive cavity still exists)
What type of body plan and cell organization do Platyhelminthes (flatworms) exhibit
Acoelomate and Tissue-Organ
Class Turbellaria: Monoecious or Diocieous
Mostly monoecious
What are the main body parts of Class Cestoda
Scolex (attachment to the host)
Strobila (the main body composed of a chain of proglottids)
What is the reproductive unit of Cestoda
Proglottids (monoecious)
What organism undergoes Transverse fission
Planaria and Paramecium
What type of body plan and cell organization do Nematoda (Roundworms) exhibit
Pseudocoelomate and Organ-system
Are Annelida Lophotrochozoans or Ecydozoans
Lophotrochozoans
What are the 3 sub-groups of Annelida
Polycheata (marine worms)
Oligochaeta (freshwater worms, earthworms)
Hirudinida (Leeches)
What is the group called when combining Hirudinida + Oligochaeta
Clitellat
What is seta
Needlelike chitinous structures of the integument of annelids, arthropods, and others
What organisms exhibit metamerism
All members of annelids, arthropods and chordata
What class exhibits psuedometamerism
Class Cestoda
What holds the ventral surfaces together during mating of Earthworms
Mucus
Where does the worm secrete around
Clitellum
What are mixed inside the cocoon
Eggs from oviducts (from genital pore)
Albumin (from skin glands)
Where does fertilization of eggs and embryonic development occur in
In the cocoon
How do polychaeta differ from other annelids
Well differentiated heads Specialized sense organs Paired paddlelike appendages (parapodia Many chatea on each parapodium No clitellum
What are found in the parapodia of polychaete
Chaetae
What do Hirudinida lack
No parapodia or setae
What type of circulatory system is seen in Mollusca
Mostly open-circulatory system. Closed in cephalopods
What are the classes of Mollusca
Gastropoda (Snails, slugs, sea slugs, sea butterflies, limpets, whelks)
Bivalvia (Mussels, clams, scallops, oysters, and shipworms)
Cephalopoda (squids, octupuses, nautiluses, cuttlefish)
What are the habitats of Cephalopods
they are exclusively marine (squids cannot live on land)
What are the body parts in Mollusc
Head-foot. EXCEPTION IN BIVALVES (feeding, cephalic, sensory, locomotor organs) Visceral Mass (Digestive, circulatory, respiratory, and reproductive organs)
What is the mantle
A sheath of skin extending dorsally from the visceral mass that wraps around each side of the body. Secretes a protective sheet in molluscs which protects soft parts.
Radula
Rasping, protrusible, tonguelike organ found in most molluscs
What is the modification seen in Bivalves
Laterally compressed foot
What is the funnel
For jet propulsion in cephalopods
What is the mantle cavity
Houses the respiratory organs (gills or a lung)
What type of reproduction is seen in Molluscs
Sexual reproduction only (mostly dioecious)
Some gastropods are monoecious
What organisms have a Trocophore Larvae
Molluscs and annelids
What are veliger larvae
Free swimming larva of most marine snails and bivalves. Develops from a trocophore.
What does the circulatory system of molluscs transport
Gases
Nutrients
Waste
Hormones
What organisms undergo diffusion
Protozoans, porifera, Platyhelminthes, Cnidaria, Nematoda
Which organisms have a closed circulatory system
Annelids, cephalopods
What is the fluid found in open circulatory systems
Hemolymph (flows through vessels in some parts of the body into open sinuses of others
Why are some Gastropoda considered asymmetrical
Because of torsion in the visceral mass is asymmetrical
What reduces the effects of fouling in gastropods
The loss of the right gill. Water flows one-way in the left side, over the gill and the right side, clearing waste from the rectum.
What is the only mollusc to exploit terrestrial environments
Molluscs
What do Bivalves lack
No head and no radula. Very little cephalization.
What is ovelli
A simple eye or eyespot in many types of invertebrates
How do octupuses and cuttlefishes capture there pray
Use salivary glands that secrete a venom for immobilizing prey
What is the internal shell of cuttlefish and squid
Pen
What are chromatophores
Special pigment cells used as camouflage. Associated with alarm or courtship
What are the subphylums in Arthropoda
Chelicerata
Myriapoda
Crustacea
Hexapoda
What are characteristics found in all Arthropoda
Triploblastic Hard exoskeleton Coelomate Ecdysozoan Protostomes Complete Gut Mostly sexual reproduction Bilateral body symmetry
Why are arthropods so diverse and abundant
Versatile Exoskeleton Segmentation and specialized appendages Air piped directly into cell Highly developed sensory organs Complex behaviour pattern Trophic breadth through metamorphosis
Why do arthropods molt
To increase body size
What is Ecdysis
shedding of outer cuticle as in insects or crustaceans
What is a Tagmata
compound body section of an arthropod resulting from embryonic fusion of two or more segments. Appendages are also differentiated
What is insight learning
Adapting and learning from situations via memorization in order to construct a new response.
How many tagmata do Hexapoda have
Head + thorax + abdomen
What are the classes of Hexapoda
Entognatha
Insecta
How many tagmata do Chelicerata have
Cephalothorax + abdomen
What are the appendages of Chelicerata
1 pair of chelicerae
1 pair of pedipalps
4 pair of walking legs
What are some examples of Chelicerata
horseshoe crabs, spiders, ticks, scorpions, and mites
What are the tagmata in Crustacea
Cephalothorax + abdomen
How many antennae do crustacea have
2
What arthropod subphylum is only aquatic
Crustacea
How many tagmata do Myriapoda
Head + trunk
What do arthropods use for gas exchange
Tracheae (No Hemolymph in vertebrates)
What type of development does not include a larval stage
Ametabolous. Young and juveniles are similar to adults except in size and maturity.
What is an indirect form of development
Hemimetabolous or Holometabolous. Passes through the larval stage.
What is the difference between Hemimetabolous and Holometabolous metamorphosis
Hemimetabolous includes the nymph stage, Holometabolous include a larval stage.
What is a nymph
Resembles the adult in form and eating habits. In between egg and adult in terms of development.