Biology 2 Exam 2

Niche

Niche

job role, function that an organism takes in an environment

Extinction

animals will change to fit empty roles

Mass extinctions cause

mass change in behavior

R-selective

• many young

• very little parental care

• generalists tendency

• ex: weeds

R-selective are

more likely to survive a mass extinction

K-selective

• few young

• more parental care

• more specific

Ecological selection after a mass extinction

1st colonization→ R selective → K selective

Adaptive radiation

opens niches; adapt/occupy them

• often with founders affect; need for niche fulfillment

Nicholas Steno

• older fossils are simple at the bottom

• younger fossils are complex at the top

Radio isotopes

• undergo radioactive decay

• addition of neutrons

1/2 life

lose 1/2 of radioactivity

Continental Drift

the plates experience rifts and divergence

• plates float on a liquid mantle

During the continental drift there is a

redistribution of air/water flow, temperature, and humidity

Coreolis Effect

• result of spinning

  • everything spins on the equator

Precambrian Era

• pro-karyote→ eukaryotes → colony, specialized tissue

Eukaryotes

• nucleated cells

• much bigger

Cyanobacteria

no O2 → higher O2

• photosynthetic bacteria (nutrients from light)

• planet needed to be oxidized for free oxygen

• oxygen was toxic; makes toxic by-products

O2 radical (O2.-)

picks up an extra electron and wants to give it away

• bounce around; creates mutation

Anti-O2 radical (O2.-)

make ATP

• neutralizes oxygen; detoxifies it

• provides the energy to get big

Paleozoic Era Cambrian Period

• all animal phyla increased

  • more phyla than present day due to mass extinction

Photosynthetic eukaryotes

• can occur because O2 levels are high and O3 zones are accumulated

O3 (ozone)

protects from UV rays

Paleozoic Era Ordovician Period

marine diversity

• mass extinction (lost 75%)

  • result of glacierization (decrease of sea level)

• Volcanic activity

  • air→ particulates to the sulfur

    • reflects heat away

Paleozoic Era Silurian Period

• H2O jawless fish→ jawed fish

• colonization → land

• nonvascular plants → vascular plants

• enough O3 (arthropods and insects appear)

Paleozoic Era Devonian Period

• larger insects

  • more insects

• some animals

• fish→ amphibians (vertebrates with lobed fins)

• 75% extinction

  • meteorite hit

Paleozoic Era Carboniferous Period

• coal deposits

  • ferns dominated (large forests, humid/swampy environment")

• big amphibians→ reptiles

• cooling at the end

Paleozoic Era Permian Period

• reptile diversity

  • 95% of planet goes extinct

• 50% more oxygen here than present day

• Permian burp

Permian Burp

• more gas pressure than water lid pressure

• the bottom rotting organic matter gas escapes the water

  • CH2 and CO2

  • organic snow: everything above that dies; decays and flaked in water

Mesozoic Era Triassic Period

• lots of room for niche filling

  • develop early dinosaurs (better at adaptive radiation)

    • occupy empty niches

  • first mammals occur/ some flowering plants (not many)

  • conifer plants dominated (gymnosperms- evergreens)

    • herbivore dinosaurs ate

Mesozoic Era Jurassic Period

• dinosaurs increased diversity

• fish also went through major diversity stage

  • continents split, opened up more fish niches

Mesozoic Era Cretaceous Period

• super advanced dinosaurs

  • sophistication (modifications)

• increase flowering plants (angiosperms)

  • changes diet for dinosaurs

• mammals presence is greater

  • diversify a little more

• Yucatan Meteorite Strikes

Yucatan Meteorite Strike

• 75% mass extinction

Cenozoic Era Tertiary Period

• any dinosaurs that survived the strike became birds

• mammals made it through

  • occupy niches left

• flowering plants make it

  • begin to diversify

• insect diversify increases due to pollination

Cenozoic Era Quaternary Period

• glaciation events (numerous)

  • large mammals start to go extinct

  • hominids → Homo sapiens

    • frees up hands (easy manipulation) HUGE SPECIATION EVENT

Animals are

• multicellular; not a colony

  • cells have a relationship (organization)

    • tissues

• heterotrophs

  • food from a source and break it down

• homeostasis= constant internal environment

• most animals have motion

• particular developmental patterns

  • specific way an animals grows

2 embryonic tissues

• diploblastic

  • ectoderm

  • endoderm

3 embryonic tissues

• triploblastic

  • ectoderm

  • mesoderm

  • endoderm

Ectoderm

• epidermis and nervous system

  • outside layer

Mesoderm

• muscle, bone, cardiovascular system, kidney, renal system

Endoderm

• form GI tract, form respiratory system, and glands

Layer formation

• zygote→ morula→ blastocyst

Morula

solid mass

Blastocyst

• cells are undifferentiated

• gastrulation

  • pushing your hand into a beachball (invaginate)

  • protostome: mouth first

  • deuterostome: anus first

Symmetry

• radial

• bilateral

  • cephalization: sensory information and processor on one end

    • have a brain

Acoelomate

solid mesoderm

Pseudocoelomate

one sided mesoderm

Coelomate

split mesoderm

Heterotrophs

• filter feeders: trap food from air or water

  • sponge: sessile (settled in one spot)

  • whale (not sessile): baleen (modified teeth)

Herbivores

• plant eaters→ cellulose

  • animals don’t break down cellulose

    1. must break down cellulose

       • multi chambered sweatpants

    2. eat lots of plants (abundance)

    3. eat w/o killing the plant

       • eat strategically so the plant can grow back

Predators

• kill and eat something else

  • have morphology to capture and kill prey

  • DANGER: animals fight back

Parasite

• harm to host (can modify behaviors)

  • must evade host immune system (self vs. non self cell)

• Reproduction

  • hermaphrodite: male + female

    • produce lots of offspring

      • lay lots of eggs

Endoparasite

inside the host

• ascaris (flatworm): crawl into parts of the body

Ectoparasite

outside the host

• leech, flea

Intermediate hosts

• host juvenile form of parasite

  • not the final stage for the parasite

Detritovore

• aid in decay and breaking down of matter

  • get rid of dead and decaying matter

  • ex. earthworms

Diploblasts (2 layers; endoderm and ectoderm)

• 3 phyla

  1. Porifera: sponges

  2. Placozoa: found in deepwater trenches

     • have an endoderm and an ectoderm

     • also have fused cells (multi-nucleated)

  3. Cnidaria: jellys, corals, sea anemones

Phyla Porifera

• sponges and they are diploblastic (edo and ecto derm)

  • not colonial, have distinct tissues

  • can be broken apart, find each other again: reassemble

• Simplest sponge

  • sessile

  • filter feeder (have pores)

  • choanocytes (endoderm)

  • pull water in (gastrovascular cavity)

  • filter feed

  • ostium (mouth)

Amoeboid cells

• undifferentiated

  • distribute food

  • change into another cell

  • turn into gametes (sexual reproduction)

  • bud (asexual)- good living conditions

Spicule

some are calcium/ some are silicon (glass)

• can break skin

Phyla Cnidaria

• 2 way gastrovascular cavities

• Cnidocytes (cell)

  • stinging cells

• Nematocyst

  • will burst if triggered (touched, chemicals)

  • sends out sticky/barbed filament

    • releases a toxin

• Medula and Polyp stage

Cnidaria life cycle

polyp stage→ colony bud→ medusa stage →planula

Phyla Cnidaria- Class Scyphozoa

sperm and egg→ planula→ polyp (bud and strobula)→ medusa (ephrya)→ adult jellyfish

• have to be able to coordinate

  • have a neural network/ nerve net

  • can be photosensitive

    • ocelli: eyespots (light for dark)

    • move towards or away from light

Class hydrozoa

• polyp dominant

  • have a medusa stage for reproduction

• budding medusa→ planula→ polyp

• gastrozoid: catch food

  • have tentacles to trap and pull into GVC

• gonadozoid/gonozad: reproduce (budding medusa)

Class anthozoa (sea anemones and coral)

• all coral, no real medusa stage

• sea anemones

  • tentacles

  • Acontia: internal tentacles that have stinging cells to kill food if it is not dead in the GVC

• Coral

  • calcium carbonate base

  • symbiotic relationship with algae (zooxanthella)

    • dies when bleached

Phyla Placozoa

• found in deepwater trenches

• links porifera and cnidarians

• flat-worm like

  • planula

• Have an:

  • ectoderm: flagellated

  • syncytium

  • endoderm: glandular cells (have vesicles)

Syncytium

• one large cell with lots of nucleotides; multinuclear large cell (slime mold)

  • causes question as to whether or not a placozoa is diploblastic

Triploblasts

• ectoderm, mesoderm, endoderm

• Protostomes or deuterostomes

Protostomes

• form mouth first

• Lophotrochozoans

  • skeleton grows by adding to it

• Ecydozoans

  • molting exoskeleton (made of chitin)

Deuterostomes

• form anus first

Phyla Platyhelminthes

• acoelomates (absent body cavity)

  • solid mesoderm (depends on gas exchange)

• brains are a cluster of ganglia

• ladder-like nerve networks

• eyespots= ocelli

• chemoreceptors

• flame cells

Platyhelminthes are flat

so they can handle simple diffusion

Brain in Platyhelminthes

• brain: cluster of ganglia

  • nerves; not a true brain

  • on one end of the body; cephalization

• ladder-like nerve network

  • 2 spinal nerves coming down

    • communicating nerves

• eyespots are ocelli

• chemoreceptors: special sensory around the brain

Platyhelminthes shape and function

• flat so they can handle simple diffusion

  • flame cells: get rid of waste

    • filter everything; put back what they need

    • beginning of a kidney

• typically hermaphrodites

  • testis and ovaries in one worm

Phyla Platyhelminthes Class Turbellarian

• free living flatworms (planaria)

Phyla Platyhelminthes Class Trematoda

• flukeworms (parasitic)

  • ectoparasites

  • endoparasites

• suckers/hooks

  • attach themselves to host

• egg hatches→ intermediate hosts (snail)

• Juvenile forms

  • fish

  • animals

  • clams

Phyla Platyhelminthes Class Cestoda

• tapeworms

• No gastrovascular cavity

  • live in GI tract

  • take nutrients from the host

Mature proglottid

• male and female reproductive organs

  • budding

Gravid proglottid

• breaks off

• contains fertilized eggs

Phylum Nematoda

• roundworms

• pseudocoelomate

  • filled w/ fluid

  • hydrostatic pressure

    • pushes outward

  • creates hydro skeleton

• ungulates to move and to move things through the GI

  • 1 way gastrovascular cavity

• mesoderm is muscle

• cuticle is a

  • protective layer

  • rigid

Ascaris (Phylum Nematoda)

• male is hooked

• females are straight

  • will look for the male hook to mate with if they are not hermaphrodites