Life 121 Exam 4 Flashcards
(124 cards)
1
Q
Deuterostomes
A
clade is defined by DNA similarities. has radial cleavage and is blastopore, or anus
2
Q
chordates
A
HUGE differences in size and body mass.
Characteristics: bilaterally symmetrical, deuterostomes, coelomates, and segmented bodies
3
Q
shared derived features of chordates
A
possessed only during embryonic development for some species.
-notochord
-dorsal, hollow nerve cord
-pharyngeal slits
-muscular post-anal tail
4
Q
Notochord (chordates)
A
present in all chordate embryos, and some adults.
longitudinally located between the digestive tube and nerve cord
provides firm yet flexible skeletal support. Has large fluid-cells within stiff, fibrous tissue
5
Q
Dorsal and hollow nerve cord in chordates
A
plate of ectoderm rolls into tube
other phyla- solid, ventral
central nervous system made up of brain and spinal cord
6
Q
Pharyngeal slits in chordates
A
in the pharynx- throat
pouches separated by grooves
grooves become slits. Allows for suspension feeding, respiration (gills) and development of head neck and ears for tetrapods.
7
Q
muscular, post-anal tail in chordates
A
tail extends posterior to anus
skeletal segments in muscle
other phyla- digestive tract extends whole length of body
8
Q
cephalochordates
A
lancets
- most basal chordates
-filter feeders
-have key chordate traits
9
Q
urochordata
A
tunicates, sea squirts
-larvae
-adult- metamorphosis, loss of chordate characteristics
10
Q
vertebrates
A
vertebral column
head
11
Q
Vertebrates in the fossil record
A
cambrian period- better at capturing food and avoiding being eaten
ordovician, silurian, and devonian periods- paired fins, semicircular canals, mineralized bone
12
Q
Why mineralization of bones in vertebrates?
A
transition in feeding to predation due to armored plates and mineralized mouth parts
mineralized fin rays allowed swimming faster w better control
13
Q
petromyzontida (lampreys)
A
35 species
marine and freshwater
reduced vertebrae
adults (parasites of fish)
larvae (suspension feeder)
13
Q
Myxini (hagfishes)
A
30 living species
marine scavengers
reduced vertebrae
head (no jaws, tooth like structures)
produce slime for protection
14
Q
Gnathostomes
A
shared derived characteristics:
-jaw
-entire genome duplicated (4 sets of Hox genes)
- large forebrain for smell and vision
-lateral line system (sense vibrations in water)
sharks are example
15
Q
Chondrichthyes
A
cartilage fish, some mineralizatoin present
2 main groups- sharks rays and skates, and ratfishes
16
Q
chondrichthyes feeding
A
largest sharks and rays consume plankton
carnivores have jaws and rows of teeth that are replaced
17
Q
Osteichthyans
A
bony fish
ossified endoskeleton with a calcium phosphate matrix
18
Q
Actinopterygii
A
ray-finned fishes
-fin rays with webs of skin supported by bony spines
-almost half of all vertebrates
19
Q
Lobe-Fins
A
rod-shaped bones surrounded by thick layer of muscle in pectoral and pelvic fins
teeth covered in true enamel
20
Q
Lobe-Fins: Dipnoi
A
-six species
-southern hemisphere
-have gills and lungs
-fresh water (stagnant and swamps)
-burrow into mud when ponds shrink
21
Q
Tetrapods: Lobe-Fins with limbs
A
support weight on land
-four limbs with digits
-fusion of hip bones to backbone
-ribs
-head separated from body by neck
pharyngeal clefts
-adults lack gills
-ears glands and other structures
22
Q
Amphibia
A
-extant basal tetrapods
-association with damp habitats or microhabitats
-skin permeable to water
-ectothermic
23
Q
Amphibia examples
A
salamanders and newts
-order Urodela (retain tail)
frogs and toads
-order anura (lack tail)
caecilians
-order Apoda (legless)
24
Amphibious Life (frogs)
larval stage
-tail
-gills
-aquatic herbivore
adult stage
-lungs
-legs
-external eardrums
-carnivorous diet
metamorphosis is transition
25
Amniotes
tetrapods
produce egg equipped with an amnion
-adaptation to drier terrestrial habitats
no larval stage
derived characters
-amniotic egg w 4 specialized membranes
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Reptilia
keratinized scales
internal fertilization
lay leathery shelled eggs on land, birds have calcareous shells
ectothermic, birds are endothermic
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Dinosaurs
-dominant terrestrial vertebrates for 165 my
-great diversity in size and body form
-Ornithischians (herbivores and defense adaptations)
-Saurischians (long neck, theropods)
-endotherms
-agile and fast moving
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theropod dinos
advanced dinos
hollow bones, three-toed limbs
bipedal
feathers
origin of birds
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Birds
-largest tetrapod class, 10k species
-endotherms
-flights
-along w crocs, only
-extant archosaurs
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When did birds transition to flight
150 mya
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Aves (birds)
derived characters- adaptations to flight
weight-saving mods
-light bones, toothless, small gonads, one ovary, no bladder
high metabolism mods
-efficient respiratory and circulatory systems
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Mammals
produce milk
hair
5,300 species
arose in jurassic (180 mya)
creatceous
- 3 lineages emerged (140 mya)
-monotremes (egg laying)
-marsupials (pouch)
-Eutherians (Placenta)
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Monotremes
Australia and New Guinea
Electrolocation
Lay Eggs
lack nipples, milk secreted by glands on female's ventral abdomen
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marsupials
Australia, S and N America
Nipples
Placenta
Give birth to very young offspring
marsupium (pouch)
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Eutherians
largest group of mammals
compared to marsupials
-complex placentas and longer pregnancies
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Anatomy
biological form, the structure of an organism
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Physiology
biological function, processes and functions of an organism
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organization of animal bodies
multicellularity, cellular specialization, internal environment that differs from external
levels of structural and functional organization
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organ
functional unit
may be involved in different organ systems due to having different tissue types
liver
-digestive system
-circulatory system
-immune system
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homeostasis
steady state
maintenance of internal balance
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Homeostasis-effectors
responses to stimuli
2 major systems for controlling and coordinating responses to stimuli
-nervous and endocrine system; both work together
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endocrine system
-signaling molecules (hormones) are released into bloodstream by endocrine cells (endocrine glands)
-hormones may have effect in a single location or throughout the body
-only cells with receptors for a certain hormone can respond to it
-well adapted for coordinating gradual changes that affect entire body (growth and development, reproduction, metabolic processes, digestion
-effects can be short or long lasting
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Simple endocrine pathways
Secretin
0pH regulation of the duodenom
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nervous system
-neurons (nerve cells) transmit signals called impulses down dedicated routes, connecting specific locations
-nerve impulses travel down communication lines mainly made of axons
-other neurons, muscle cells, and endocrine and exocrine calls can all receive nerve impulses
-nervous system communication usually involves more than one type of signal (voltage changes, neurotransmitters)
-well suited for directing immediate and rapid responses like locomotion and behavior
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thermoregulation
process by which animals maintain an internal temperature within a tolerable range
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heat transfer
from object of higher temp to one of lower temp
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importance of thermoregulation
enzymes work at optimum temperature
proteins denature at high temps and cell membranes become fragile as temperature rises
body fluids become more viscous at low temps
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vasodilation
part of thermoregulation.
widening of the diameter of superficial BV. increases heat loss in high temperatures
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vasoconstriction
narrowing of superficial BV. decreases heat loss when cold
part of thermoregulation
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hypothalamus
thermoregulation control center
triggers heat loss or generating mechanisms
fever is the result of a change to the set point of the biological thermostat
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ecology
study of interactions between organism and environment.
interactions occur at different hierarchies or levels
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levels of biological hierarchy
organismal ecology
-level of organism
-anatomy, physiology, immunology, behavior, and individual interaction w environment
population ecology
-interactions of individuals of the same species in an area
-population and size factors that influence it
community ecology
-group of populations of different species in an area
-interactions between species
-community structure and organization
ecosystem ecology
-community of organisms in an area and physical factors with which the organisms interact
-energy flows and chemical cycling
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Latitudinal gradients and species richness
tropical regions have more species abundance and diversity
key factors in latitudinal gradients of species richness include evolutionary history and climate
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Climate
Long term prevailing weather in an area. NOT the same as weather
determined by solar energy inputs and the Earth's movements
significant influence on the distribution of organisms
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Latitudinal gradients
solar energy impacts climate
there are temperature gradients due to the earth being a sphere, and uneven heating of the sphere
uneven heating results in air movement and precipitation gradients
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regional effects on climate
seasonality
-earths tilted axis of rotation and annual passage around sun
-causes variation in day length, solar radiation, temperature, regional precipitation, and wind patterns
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mountains
have windward and leeward precipitation
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effects of vegetation on climate
forested land compared to deforested regions
forested regions means more precipitation.
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biomes
major life zones
characterized by vegetation type in terrestrial biomes
biomes- major life zones that correlate w climate
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tropical forest biome
equatorial regions
heavy rainfall
high temperatures
intense light competition for plants
highest animal diversity of terrestrial biomes
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desert biome
30 latitudes or interior of continents
low and highly variable precipitation
high mac or low min temperatures
heat and desiccation tolerance, water storage, reduced leaf surface, physical and chemical defenses in plants
water conservation and nocturnal activity in animals
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Savanna Biomes
equatorial regions
long dry season and 30-50cm precipitation
warm year round
fire-adapted and drought-resistant, physical defenses, grasses in plants
animals are large herbivores and predators, and migrations
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Chaparral biome
midlatitude coastal regions
rainy winters and dry summers
cool fall, winter and spring, hot summers
drought tolerance, fire adaptation in plants
browsers, high diversity of small mammals in animal species
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temperate grassland
interior of continents
highly seasonal precipitation, up to 100cm
cold winters and hot summers
grasses and forbs dominate, drought and fire adaptations, grazing
animals are large ungulate grazers, and burrowing animals
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temperate broadleaf forest biome
midlatitudes
medium to high amounts of rain in any season
winter temperatures around freezing, hot and humid summers
plants have vertical layers in canopy, and leaves that drop in the winter
animals have Avian migration, and mammal hibernation
66
Northern Coniferous Forest Biome
northern portions of holarctic region. largest terrestrial biome on earth
periodic droughts common. 30-70cm
winters cold, summers hot
cone bearing trees, fire adapted, water conservation, shape to prevent accumulation
migratory birds, year-round inhabitants
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tundra biome
high winds and low temperatures
low precipitation in the arctic, high precip in alpine
cold winters, mild and short summers
herbaceous plants
grazers, migratory animals
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population ecology
interactions of individuals of the same species in an area
population size and the factors that influence it
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population
definition- a group of individuals of a single species living in the same general area
described by their boundaries and size
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species distributions
distributions are the result of ecological and evolutionary interactions through time
-evolutionary history
-ecological factors
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dispersal
the movement of individuals away from centers of high population density or from their area of origin
dispersal contributes to the global distribution of organisms
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dispersal transplants
aka invasive species
indicate if dispersal is a key factor limiting species distributions
organisms that are intentionally or accidentally relocated from original distribution
if successful (survive and reproduce), it indicates that species' range is larger than its actual range
can disrupt the communities or ecosystems to which they have been introduced
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examples of abiotic factors
availability of water
-important in species distribution
-desert organisms exhibit adaptations for water conservation
temperature
-important due to effects on biological processes
-below 0 cells freeze and rupture
-above 45 proteins denature
-most organisms function best within a temp range
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population size
can't count
sampling techniques used to estimate densities and total population sizes
density can be estimated by extrapolation from small samples or an index of population size
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density and dispersion
density- number of individuals per unit area or volume
dispersion- pattern of spacing among individuals within the boundaries of the population
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patterns of distribution
environmental and social factors influence spacing of individuals
clumped- individuals aggregate in patches. most common pattern
uniform- individuals evenly distributed. influenced by social interactions, like territoriality.
random- position is independent of other individuals. Absence of strong attractions or repulsions
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what makes up population density
demography- study of a populaton's vital statistics and how they change over time
death and birth rates
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life tables
age-specific summary of the survival pattern of a population
made by the fate of a cohort. follows a group of individuals of same age from birth to death
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survivorship curves
graphic way of representing life table data
plot proportion or numbers of a cohort still alive at each age
classified into three types
many species are still intermediate to these curves
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three types of survivorship curves
type I
-low death rates during early and middle life and increase in death rates among older age groups
type II
-constant death rate over the organism's life span
Type III
-high death rates for young and lower for survivors
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exponential growth
when do we see exponential growth
-populations in new environments
-rebounding populations
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carrying capacity
exponential growth cannot be sustained for long in any population
a more realistic population model limits growth by incorporating carrying capacity
carrying capacity (k)
-max population size environment can support
-varies w abundance of limiting resources
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logistic growth model
the per capita rate of increase declines as carrying capacity is reached
an exponential model with an expression that reduces per capita rate of increase as N approaches K
fits few real populations
useful for estimation of possible growth
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population dynamics
influenced by life histories
influenced by mechanisms that regulate population density
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life histories
traits that affect an organism's schedule of reproduction and survival
-age what reproduction begins
-how often an organism reproduces
-how many offspring are produced each reproductive cycle
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life history trade offs
some selective pressures may influence the trade-off between number and size of babies
young likelihood to die, lack or no lack of prenatal care
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life histories more
k-selection
-density-dependent selection, traits sensitive to pop density
k-type population
-b rates fall and d rates rise w pop density
r-selection
-density-independent selection
-selection of traits that maximize reproduction
r-type population
-b rate and d rate don't change w density
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mechanisms of DD population regulation
DD b and d rates can have negative feedback regulating pop growth
can be affected by many factors including: competition, territoriality, disease, predation, toxic wastes, other factors
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competition (DD)
occurs over resources in crowded populations
increasing density increases competition- lower b rate
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wastes (DD)
toxic wastes can accumulate in environment. DD regulation of population size
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predation (DD)
predation may increase w increasing pop size due to predatory preference for abundant prey species
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territoriality (DD)
can limit pop density when space is limited resource
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disease (DD)
disease pathogen rates may increase with increasing pop density
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immigration, emigration, and metapopulations
metapopulations
-local pops linked by immigration and emigration
local pops
-occupy patches of suitable habitat surrounded by unsuitable habitat
-replaced in patches after extinction
-established in new unoccupied habitats through migration
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niche
an organism's ecological job within a community
includes physical and environmental conditions a species requires, as well as interactions with other species
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interactions among species
interspecific interactions- interactions among different species
competition, predation, herbivory, symbiosis (mutualism, commensalism, parasitism)
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competition
individuals of diff species compete for resource that limits their growth and survival
one species will reduce availability of resource for the other
effect is bad for both species, both have reduction in fitness
2 outcomes
-competitive exclusion
-niche specialization
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competition outcomes
competitive exclusion
-2 species competing for same resource can't coexist
-more efficient organism will outcompete, reproduce, and eliminate competitor
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competition outcomes
resource partitioning and niche specialization
-results in organisms using diff resources and coexisting
-resources used differently across space and time
resource partitioning
-results in species using resources differently
-selection favors traits allowing more efficient use of available resources
niche specialization
-results in species specializing within a niche
-selection favors species that focus on a subset of resources due to less competition
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niche partitioning and evolution
enables species to coexist by avoiding direct competition
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fundamental v realized niche
realized niche- portion of niche actually occupied
fundamental niche- portion that could be potentially occupied; includes realized niche
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predation
predators evolved adaptations to capture prey
-find and identify
-catch and subdue
-behavior- pursue v ambush
prey evolved to avoid death
-behavioral defenses
-morphological defenses
-physiological defenses
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herbivory
plants aren't mobile, yet also evolved to avoid being eaten
-chemical defenses
-defensive structures like spines thorns and awns
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symbiosis
direct and intimate relationship between individuals of two or more species
parasitism- parasite benefits, host harmed
mutualism- both benefit
commensalism- one benefit, one left same
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diversity of community
species diversity
-variety of diff organisms in a community
-components- species richness (number of species) and relative abundance (proportion of species in community)
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diversity
two communities can have the same species richness but a different relative abundance
diversity index- used to compare diversity among communities
shannon diversity index (H)
-accounts for species richness and evenness of species abundance
-higher H indicates greater diversity
107
benefits of community diversity
communities with higher diversity are :
-more productive and stable in productive
-produce biomass more consistently than single species plots
-better able to withstand and recover from environmental stresses
-more resistant to invasive species. (organisms that become established outside their native range)
108
trophic structure and organization
Trophic structure
-the feeding relationships between organisms in a community
-a key factor in community and ecosystem dynamics
food chains
-trophic levels from producers to top carnivores
-transfer of food energy nutrients from one level to the next
food webs
-food chains not isolated
-branching food chain w complex trophic interactions
-species may play role in more than one level (predator and prey)
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community diversity and composition
certain species have large impacts on a community
-highly abundant or play a pivotal role in community dynamics
Dominant and keystone species, and ecosystem engineers
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dominant species
dominant species
-most abundant or have highest biomass
-removal from community may have negligible impact
American chestnut tree
-was a predominant tree in range, now few mature trees survive in home range.
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keystone species
not abundant but exerts strong control on community structure through ecological role (niche). Removal results in large impact on community.
112
disturbance
certain events can create significant changes on the structure and function of a community
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non-equibulibrium model of communities
it was believed that the disturbances slowed down the creation of a final climax stage
some disturbances associated with various with various biomes
communities include organisms that have adapted to disturbances
model- communities are constantly changing
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ecological succession primary
primary succession
-begins in barren lifeless areas
-bare rock after a glacier has retreated or lava has solidified
-pioneer species include bacteria, lichens, mosses
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ecological succession secondary
secondary succession
-occurs where a previous community and is re-established after a disturbance
-soil and nutrients are present and some organisms as well
-examples include old field succession or regular intensity fire
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biogeography
-the study of the distribution of species and communities in the geographic space and through geological time
-biogeographic factors are large-scale environmental conditions and physical features that influence the distribution and abundance of species
biogeographic features that influence community diversity
-latitudinal gradients and climate
-area effects
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area effects
larger areas
-more biodiversity because because variety of habitats
-support a greater number of species
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island equilibrium models
islands
-isolated habitat patches surrounded by unsuitable or diff environments
dynamic state where species immigration to an island balances species extinction on that island
determinants of species richness.
-immigration rate of new species. over time less new species
-species extinction rate
119
ecosystem ecology
regardless of size, ecosystem dynamics involve two main processes
-energy flow
-chemical cycling
ecosystem ecologists study the transformations of energy and matter within ecosystems
120
energy flow laws of thermodynamics
first law: YOU CAN'T WIN
-energy cannot be created or destroyed, only transferred or transformed
-Energy enters ecosystem as solar radiation - transformed into chemical energy by photosynthetic organisms
second law: you can't break even
-every exchange E increases the entropy of the universe
-E conversions are not completely efficient- some E is always lost as heat
-continuous input from the sun is required to maintain E flow in Earth's ecosystems
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chemical cycling: conservation of mass
chemical elements are continually within ecosystems
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Primary production (PP)
amount of the light E converted to chemical E by autotrophs during a given time period
E budgets
-photosynthetic production sets the spending limit for an ecosystem's energy budget
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production
gross primary production (GPP)
-total PP
-measured as the conversion of chemical energy from photosynthesis per unit time
Net primary production (NPP)
-GPP minus E minus 1 degree used by producers for autotrophic respiration
-energy available to consumers
