BIO 114 EXAM 3

movement of water in plants 

from the roots (+) to the leaves (-)

movement of sugar in plants 

from the leaves (+) to the roots (-)

casparian strip

waxy substance that makes up the outer layer of the endoderm, forces water to stop moving through the cell wall and into the cytoplasm

plasmodesmata

small opening between the endoderm and cortex cells which allow entry of water through the cytoplasm of adjacent endoderm cells (**are also attached to ER and allow for fast transport)

capillarity

the adhesion (attraction) of water molecules to the sides of the tubes which act as a driving force for water moving up the xylem

guttation

a “necklace” of water droplets that collect on a leaf at night when photosythesis stops and excess water is secreted from the stomata

translocation

movement of sugars up and down the phloem 

positive pressure flow hypothesis

(regarding translocation) the movement of sugars from the source cell to the sink cell

phloem loading

• occurs at the leaf

• from pallisade parenchyma cells —> sieve tube cells of the leaf phloem

• active transport of moderate concentrations of sucrose from the leaf and into the sink cell

• diffusion to the sieve cells of the phloem

phloem unloading 

• movement of sugar into the root phloem to the root companion cells and then to the cortex cells of where sugar is stored 

• membranes between the phloem and xylem are not permeable to sugar which is why sugar diffuses into the companion cells and then actively transported to storage areas in the root cortex 

movement of sugars in the springtime

sugars are actively transported from the root cortex to the companion cells and then by diffusion pass into the root phloem

choanoflagellate protists

closest living relatives of the animals

phylum porifera

• sea sponges!

• most ancient animal phylum with living representatives

• similarities between the feeding cell members of the choanoflagellate and choanocyte cells of the sponges

microfeeders

flagellated collar cells that evolved to help sponges survive by allowing them to consume the smallest organisms suspended in water (i.e., bacteria and protists)

germ layers

responsible for producing a characteristic subset of structures and organs in the adult animal

no primary germ layer

sea sponges (porifera)

diploblastic

creates two major germ layers in which structures develop

1) ectoderm

2) endoderm

triploblastic 

creates two major germ layers in which structures develop

1) ectoderm

2) endoderm

3) mesoderm 

ectoderm

(a germ layer)

the outer layer that gives rise to the skin and nervous system structures

endoderm 

(a germ layer) 

the inner layer that gives rise to the lining of the digestive tract 

mesoderm

(a germ layer) 

the middle layer that gives rise to muscle, bones, and most organ systems

cephalization

the development of a head where sense organs and nervous tissues are concentrated at the leading edge of movement

asymmetry

the animal cannot be divided into equal halves, but rather opposite halves (i.e., sponges)

radial symmetry 

an animal that can be divided into multiple planes 

bilateral symmetry

the animal can be divided into two equal halves 

body cavity

separates the internal organs from the body wall

**only for animals with a mesoderm layer

acoelomate

no body cavity exists (i.e., flatworms)

pseudocoelomate

body cavity but without the mesodermal lining of organs

allowing for better diffusion of substances inside an organism and maneuverability

**note: a certain amount of rubbing between the organs and body wall occur in these animals (i.e., nematodes)

eucoelomate 

animal has a body cavity and internal organs covered with a membrane derived from the mesoderm

provides protection from rubbing and antigens entering the coelom from a wound

blastopores

a cluster of cells that originated from a zygote undergoing cleavage (dividing repeatedly)

protostome 

a blastopore in which the mouth is formed first

deuterostome

a blastopore in which the anus is formed first

phylum porifera

• sea sponges

• asymmetric

• no germ layers

• did not give rise to any existing phyla

phylum cnidaria 

• jellyfish, sea anemones, corals 

• diploblastic 

• radial symmetry 

• use nematocysts (stinging cells) in cnidocyte cells to capture prey or use it for defense

lophotrocozoa and ecydozoa 

two distinct superphyla in the animal kingdom that distinguish INVERTEBRATES by structural features 

lophotrocozoan protostomes

• triploblastic animals with bilateral symmetry

• blastopore becoming a mouth (protostome)

• growth by incremental additions (they do not have to shed in order to grow)

• includes phylum platyhelminthes, annelida, and mollusca

ecydozoan protostomes

• triploblastic animals with bilateral symmetry

• blastopore becoming a mouth (protostome)

• growth occurs via repeated shedding of the outer body exoskeleton (ecdysis)

• includes phylum nematoda, arthropoda, echinodermata 

phylum platyhelminthes

• flatworms, parasitic flukes, and tapeworms

• most primitive groups have bilateral symmetry, cephalization, and tube-within-a-tube design

• flat body maximizes surface area for the diffusion of gases (they have no respiratory system)

• bottom-dwelling, flat, slow-moving scavengers

phylum annelida

• evolved from a free-living flatworm and includes earthworms, predatory marine worms, and leeches

• marine worms were the first annelids and eventually evolved to live in freshwater

• hydrostatic (liquid-inflated) skeleton and gripping setae (bristle hairs essential for movement)

• segmentation (repetition of body parts along the body axis)

phylum mollusca 

• chitons, snails, clams, squids, octopus

• the second largest phylum after arthropods 

• adaptive radiation due to several innovations including a mantle, protective shell, muscular foot, and scraping radula, all of which allowed them to feed on suspended and attached algae near shore 

• only snails moved to land

phylum nematoda

• evolved from a flatworm ancestor

• tolerant of a variety of extreme conditions including drought, freezing, and boiling, O2 depletion, and low pH

• evolved a cuticle (dehydration resistant body covering that is shed to permit growth)

• disgusting freaks that can give other animals trichinosis and elephantiasis

phylum arthropoda

• insects, crustaceans (crabs, lobster, shrimp) and spiders (mites, ticks, scorpions, etc)

• the largest phyla in the animal kingdom

• evolved from an annelid ancestor

• chitinous exoskeleton helped them move from water and out onto land

• evolved a tracheae system (small breathing tubes to the inner body parts) and a compound eye (to spot food from a distance)

deuterostome phyla

• the “second mouth” (because the anus developed first)

• bilateral symmetry, triploblastic germ layer, eucoelomate body cavities

phylum echinodermata

• starfish, sea stars, sea urchins, and sea cucumbers

• the closest non-chordata relatives to the chordates based on genetic info and larval type (although the common ancestor is unknown)

• slow-moving, omni-directional, heterotrophs

• gripping suction cups for locomotion and predation

phylum chordata 

• ALL WITH A NOTOCHORD (an embryonic structure that later disintegrates into development)

• more mobile and rigid-bodied heterotrophs

• increase in cephalization 

• pharyngeal gill slits, dorsal hollow nerve chord, post anal tail 

• fish, lizards, snakes, sharks, mammals (humans)

• has 3 subphyla: urochordata, cephalochordata, verebrata

6 major classes of verebrata

• Condrichthyes (cartaliginous fish such as sharks and rays, the first chordates with jaws)

• Osteichthyes (bony fishes—includes all feeding modes)

• Amphibia (frogs, toads, and salamanders, first chordates to invade land)

• Reptila (lizards, snakes, turtles, and crocodiles) 

• Aves (birds—first chordates adapted for flight)  

• Mammalia (mammals) 

3 subgroups in mammalia

• monotremes

• marsupials

• placentals

monotremes

egg laying mammals (mammalia)

marsupials

pouched mammals (mammalia)

placentals 

animals that have a placenta (mammalia) 

plasticity

ability to change under environmental conditions

generalists

• good in everything, master of nothing

• WILL EAT ANYTHING!!!!!!!!!

• more competition, but no scarcity of food sources (if something were to happen such that one of their food sources is gone, they’d be fine)

• ex) the jungle crow (will eat fruits, insects, and garbage)

specialists 

• picky eaters of the animal kingdom 

• less competition for food source, however if something were to happen such that the food source is gone, could be detrimental to the animal

• ex) hummingbirds only consuming a particular nectar 

energy source variability

different energy sources demand different (mostly incompatible) adaptations to access them

ex) the evolutionary design of plants makes it such that they cannot eat other organisms since they can only make their own food

endotherms

animals that use internally generated heat to maintain body temperature. (i.e., humans, bears, prairie dogs, birds)

body temperature will tend to stay steady regardless of environment

ectotherms

depend mainly on external heat sources and their body temperature changes with the temperature of the environment (i.e. iguanas, rattlesnakes, frogs, fish and DAPHNIA magna!!)

using energy

will differ across all animals. octopi will “live fast die young” whereas the Galapagos giant tortosises can live up to 100 years

SA:V ratio

smaller for big animals, but bigger for smaller animals

things that decrease with an animals size (decrease in SA:V ratio)

• heat loss decreases

• dehydration rate decreases

• number of predators decreases

• number of shelter options decrease

• the only thing that INCREASES is teh absolute amount of food and water (remember though!! 200,000 mice with the same amount. of weight as one elephant will need more food because their metabolic rates are much faster due to higher SA:v ratio)

aposematic coloration

a physical warning to predators, often bright colors aimed at making prey stand out, but these animals will often be distasteful when consumed (nausea inducing, or event toxic)

ex) the poison dart frog

unrelated distasteful species who use similar a coloration/evolve to look alike is known as Müllerian mimicry

Batesian mimicry

a non-distasteful/non-toxic species will evolve to look like a distatseful species in order to escape predation

cryptic

camouflage

ex) the Oldfield mouse

Gulf toadfish and bottlenose dolphins

dolphins produce sounds when foraging, including low frequency “pops” that can be heard by the toadfish.

toadfish exposed to these “pop” sounds will reduce their call rate by 50%

flight initiation distance

how close a predator can approach before the prey can flee

prey condition

body size, reproductive state, sex, age, temperature, group size, crypsis, hunger, morphological defenses

predator condition

speed, size, directness, attack, predator type, starting distance, number of predators, predator intent

refuge

distance to refuge, light, time of day, habitat type, patch quality

finding a mate

1. visual (i.e, male bowerbirds build a structure to attract females, decorated with sticks and brightly colored objects)

2. auditory (ex birdsong)

3. chemical (ex pheromones are chemical substances produced and released into the environment, male silk moths can detect them with their antennae to find unmated females)

4. tactile (water striders produce ripples on the surface of the water in different patterns including specific signals for calling mates)

monogamous

mating with only one male or female

polygamous 👯‍♀

mating with more than one FEMALE

polyandrous 🤼‍♂

mating with more than one MALE

maximizing reproductive stress

animals are evolved for this to occur, this results in a trade-off in quality vs quantity of offspring

ex) red-tailed hawk laying two eggs

even though only one chick will survive a majority of the time and this might seem like something maladaptive, if there happen to be plenty of food resources at the time of the hatch, then both chickens survive. this shows us that trait evolution involves GOOD COMPROMISES NOT PERFECTION!

Bergmann’s Law

smaller animals are found near the equator and bigger animals are found in colder climates

bigger animals have better heat retention and smaller bodied animals have higher heat dissipation

logistic population growth

• exponential growth 📈

• stops once it hits (K) the carrying capacity

• comes closer to predicting real populations than the exponential model does

demography

the study of factors that determine the size and structure of a population over time

life tables

summarizes the probabilities that an individual age class will survive and reproduce in any given year over an individuals lifetime

cohort

individuals all born at the same time and represented by an age class

fecundity

the number of offspring an individual can have in its lifetime (more specifically the number of female offspring)

life history

how an organism allocates energy and effort into the processes of growing, reproducing, and maintaining its body

the balancing of these processes is called life history trade-off

populations with high fecundity

• low survivorship (mustard plant)

populations with high fecundity

higher survivorship (coconut palm)

caribou case study

• populations on St. Paul island crashed (exponential model) and species went extinct

• populations on St. George island remained more stable

assumptions of the exponential growth model

everybody in the population is the same (same r value)

ex) the bacteria that just divided seconds ago and the bacteria that divided hours ago have the same r value

intrinsic components of the logistic growth model

• (rN)

• mainly about the growth rate, birth and death of individuals in a population

extrinsic components of the logistic growth model

• (k-n)/k

• mainly about the environment, carrying capacity

density independent growth

• (in the logistic model)

• the population before it reaches the inflection point

density dependent growth

• (in the logistic model)

• the population after it reaches the inflection point and hits the carrying capacity (K)

population inertia

existence of a population beyond the carrying capacity for a long period of time

endangered

a species that is still in the early exponential growth phase of a logistic model

threatened

a species very close to the inflection point

delisting level

• a species that has now reached the inflection point

• federal gov no longer has control over conservation efforts, it is now in the hands of the state  

management goal

• a species is basically at its carrying capacity

• the state has to monitor the species to ensure theres no major crash in its population

fundamental niche

the full range of environmental conditions where a species can survive and reproduce without limitations from other species.

no (-) encounters.

realized niche

the actual, smaller portion of that fundamental niche where the species lives due to biotic factors such as competition and predation.

post-(-)-encounters.

intraspecies competition

competition that occurs between the same species

ex) two male deer fighting one another over a mate

interspecies competition

competition that occurs between species

ex) snakes and birds competition over mice to eat

interference competition

individuals are actively going against one another to compete for a resource (will target the competitor)

scrambled competition

individuals will compete for a resource but indirectly (with one of the other being aware of it)

(aka exploitative competition)

what kind of interaction is competition 

(-,-) 

costs for both individuals partaking in it

major cause of density dependent growth

intraspecies competition

its what contributes to the “chasing” of K.

population almost at it’s carrying capacity. there’s less resources and therefore more competition within the species.