Bio II Exam II

multicellular

are animals unicellular or multicellular

heterotrophs

are organisms that cannot produce their own food and rely on consuming other organisms for energy.

animals= heterotrophs

plants= autotrophs

plants, bacteria= cell wall

animals= no cell wall/flexible

animals= nervous system/muscle system allows movement

plants=stationary

animals= sexual reproduction

differences between animals and plants

body symmetry, # of germ layers, embryonic development

differences in animal phyla

radial

symmetry with infinite number of planes

no symmtery

the lack of any symmetry in an organism's body plan. Parazoans, like sponges, do not show any distinct shape or organization.

bilateral

symmetry that includes one plane, a left and right side; most phyla have this

blastula

hollow ball of cells formed when a zygote divides by mitosis

how do germ layers form

one side of the blastula folds in and the cells rearrange to form a gastrula with 3 embryonic layers

endoderm

innermost germ layer lining of the future digestive tract

ectoderm

outermost germ layer that will give rise to the skin and nervous system

mesoderm

middle layer of germ layers that will give rise to muscles and most internal organs

deuterosome

blastopore forms anus first then mouth later

protostome

mouth forms first from blastopore

gastrulation

first opening in embryo

triploblastic

three layers (most animals)

diploblastic

two layers (some animals)

blastopore

during the process of gastrulation, the endoderm forms an opening called___

body cavity

space that houses internal organs

coelom

fluid filled body cavity

coelomates

bilateria where it contains a true body cavity

pseudocoelomate

bilateria where coelom is not completely lined with tissue

acoelomate

bilateria that lacks a fluid filled cavity

false

plants have segmentation

segmentation

body is divided into regions called segments

allows for specialization of body regions

backbone

segmentation in fish

appendages for eating, walking, swimming

segmentation in lobsters

chordata

only phylum that includes vertebrates

vertebrates

animals with a backbone

invertebrates

animals that lack a backbone, 96% of animals

phylum porifera

sponges

phylum porifera

no true germ layers or tissues

draw water in through pores

spongocoel

central cavity in porifera where water is drawn in through pores

osculum

water flows out of this large opening at the top of porifera

sessile polyp

stationary body form of cnidaria; tubular body opening at top with tentacles (hair)

motile medusa

mobile body form of cnidaria; umbrella shaped body

cnidocytes

stinging cells in cnidaria which function in defense or capture of prey

nematocyst

powerful capsules with an inverted coiled and barned thread in cnidaria

platyhelminthes

Lophotrochozoa clade; flatworm, triploblastic, acoelomate, one opening, bilateral symmetry, reproduce sexual or asexual

rotifera

pseudocoelomates, separate opening for mouth and anus, mastax for breaking up food, parthenogenesis for reproduction

parthenogenesis

Unfertilized diploid eggs develop into females, females can reproduce with no male, embryo develops from an unfertilized egg

mollusca

have a soft body under protective external shell

muscular foot for moving

visceral mass with internal organs

mantle that secretes a shell

coelomate, open circulatory system (has hemolymph), metanephridia, radula

metanephridia

excretory organ in mollusca that removes nitrogenous and other wastes

radula

mollusca have a tongue like organ that is used for eating plants or breaking shells of other species

annelida

segmented worms (marine worms, tube worms, earthworms, leeches)

closed circulatory system—> respire through skin= most environment

1. components of body are repeated in each segment— if component fails, other segments will still function

2. Coelom acts as a hydrostatic skeleton

3. specialized functions based on segment (movement, etc.)

nematoda

small, thin worms (roundworms)

all types of habitats, can be parasitic

pseudocoelomates

complete digestive system (mouth, pharynx, intestine, anus)

sexual reproduction

arthropoda

most diverse phylum, exoskeleton, segmentation, joint appendages

have exoskeleton—> conserve water and colonize land

open circulatory system

require specialized organs for gas exchange (feathery gills, tracheal system)

complex digestive system

echinodermata

modified radial symmetry (5 parts)

no brain, only simple nervous system

Radial= adults

Bilateral= larvae

coelomate

EX: starfish

chordata

1. Notochord—> flexible rod in between digestive tract and nerve cord, provides skeletal support

2. dorsal hollow nerve cord—> tube that develops into the brain and spinal cord (vertebrates)

3. pharyngeal slits—> slits close to mouth where water enter through mouth and exits through slits—> feedings, gas exchange

4. postanal tail—> locomotion

vertebrates

similar to chordates, have vertebral column, cranium, endoskeleton or cartilage/bone

vertebral column

notochord is replaced by a bony or cartilaginous column of interlocking vertebrae

cranium

nerve cord forms brain enclosed in protective bony or cartilaginous cranium

endoskeleton of cartilage or bone

provides structural support for vertebrates, made of bone or cartilage

cyclostomes

eel like fish that do not possess jaws, “circle mouths”

hag fish

marine cyclostomes that lack eyes, jaws, fins, and vertebrae

lampreys

similar to hagfish, lack a hinged jaw and true appendages, have a notochord

cyclostomata

jawless fish

gnathostomes

jawed vertebrates

chondrichthyans

cartilaginous fish that have a skeleton composed of flexible cartilage (Sharks, skates, rays)

2 chambered heart (atrium and ventricle)

single circulation:heart—>capillaries—> gills—> heart

osteichthyans

bony fish

actinopterygii

ray-finned fish, fins supported by thin, bony rays, moved by interior muscles

EX: lionfish, moray eels, sea dragons, cod and salmon

sarcoptergii

lobed finned fishes, fins supported by skeletal extensions moved by muscles in fins

tetrapods

transition from water to land animals; represents immediate state between ancestral form and descendants

amphibians

can live on land but must return to water to reproduce

buccal pumping—> close and raise floor of mouth

have thin skin to absorb oxygen directly through

3 chambered heart

external fertilization—> female lays eggs, male fertilized with sperm

metamorphisis

amniotes

desiccation (drying out) resistant eggs

allows animals to lay eggs in dry places

4 separate membranes

amnion

innermost membrane which protects developing embryo in amniotic egg

yolk sack

contains nutrients in the form of ___ for amniotic egg

allantois

disposal sac for metabolic waste in amniotic egg

chorion

gas exchange between embryo and surrounding air for amniotic eggs

adaptations for amniotes

1. dessication resistant skin—> thick and water-resistant skin

2. thoracic breathing—> coordinated muscle contractions in rib cage sucks air in and forced out

3. water conserving kidneys—> concentrate waste prior to elimination conserves large amounts of water

   1. internal fertilization—> sperm is deposited into body of female fusing with egg and forming zygote

reptiles

lizards, snakes, turtles, crocodilians

ectothermic (can’t regulate body temp) —> must absorb external heat

birds

part of reptile lineage with modifications that traded scales for wings/feathers

endothermic—> use heat generated by metabolism to maintain body temp

lay eggs and take care

have lightweight bones

have reduced in size or lacking organs

9 air sacs that expand and contract during inhalation and exhalation

mammals

1. mammary glands for secreting milk

2. hair—> endothermic and acts as an insulator

3. specialized teeth—> for different diets

4. enlarged skulls—> enlarged brain

monotremes

egg laying mammals

marsupials

brief gestation, give birth to tiny embryonic offspring, complete development while attached to mother’s nipples

eutherians

mammals that bear fully live young; placental mammals

EX: kangaroo, dog, horse

tissue

association of many cells that have a similar structure and function

1. muscle

2. nervous

3. epithelial

4. connective tissue

muscle tissue

cells specialized to shorten/contract generating the mechanical forces that may produce body movement

nervous tissue

A complex network of cells called neurons that receive, generate, and conduct electrical signals from one part of an animal’s body to another

epithelial tissue

sheets of densely packed cells that cover the body or individual organs and line the interiors of various cavities inside the body

connective tissue

connect, surround, anchor, and support structures of animal’s body

• blood

• adipose tissue

• bone cartilage

• loose and dense connective tissue

organ

composed of two or more kinds of tissues arranged in various proportions and patterns

homeostasis

a dynamic process as variables within the body are constantly fluctuating in response to external environmental conditions

regulating body temperature in mammals

neurons/skin=sensors; effectors= muscles; if body temp decreases, muscles contract which leads to shivering

negative feedback loop

mechanism that moves a variable back to set point

EX: drop in blood pressure due to an injury and loss of blood—> prevents from getting too high

osmoregulators

maintain stable cellular levels of ions and water, requires a lot of energy

osmoconformers

animals that are able to match the osmolarity of extracellular and intracellular fluids to the fluid environments they live in

use less energy

neuron

basic building block of the nervous system

nerves

bundles neurons in groups

dendrites

receive signals from neighboring neurons and carry them back to cell body

cell body

contains cell nucelus; relays information down to the axon

axon

a thin, long structure that transmits signals from the cell body to the axon terminal

axon terminal

last step for the relay of information inside the neuron

central nervous system

brain and spinal cord

peripheral nervous system

cranial and spinal nerves

myelin sheath

covers the axon of some neurons to insulate and help speed neural impulses

terminal buttons

axon from junctions with other cells and release neurotransmitters

action potential

an electrical current sent down the axon

electrical activity causes neurons to fire

synapse

space between neurons