midterm

population

a group of organisms of the same species populating a given area
-species make up populations which then make up communities
-studied by examining geographic range, growth rate, density/distribution, & age structure

population distribution

describe the way individuals are spaced out across their range

clumped population distribution

-packed closely together
-can help animals avoid predators
-school fish, flocking birds

uniform population distribution

-individuals are evenly spaced
-individuals compete w/ one another for space or resources
-orchard, penguins

random population distribution

-individuals spaced out unevenly
-when the location of an individual in a population is independent of others
-trees, dandelions

limiting factor

anything that constrains a population's size and slows or stops it from growing

density dependent factors

limiting factor that depends on population size
-competition
-predation
-parasitism and disease
-food/resource availability

density independent factors

limiting factor that affects all populations, regardless of population size
-unusual weather (affects food chains and food webs)
-natural disasters (tornadoes, hurricanes, etc.)
-human activity (destruction of habitat, introduction to non-native species)

exponential growth

occurs when population size increases dramatically over time

logistic growth

begins with period of slow growth followed by a brief exponential growth before leveling off at a stable size

carrying capacity

the largest population that an area can support
-when a population goes over carrying capacity, density-dependent factors affect it greatly.

population growth

determined by the birth rate, death rate, immigration rate, and emigration rate.

population +/- equation

birth+immigration - death+emigration

birth/death rate

-more deaths = population decrease
-more births = population increases

immigration

movement of individuals into an area w/ an existing population
-more immigration = population increase
-speed of immigration/emigration depends on species' speed, travel distance, & if human activity moves them around/
(squirrels immigrating in search of food, population +)

emigration

movement of individuals out of a population
-more emigration + population decrease
-speed of immigration/emigration depends on species' speed, travel distance, & if human activity moves them around/
(local food shortage causing emigration, population -)

biotic factors

are living factors in an ecosystem (plants, animals, insects, fungi, bacteria, etc.)
-predation
-parasites

abiotic factors

nonliving factors in an ecosystem (terrain, temperature, humidity, precipitation, etc.)
-weather

niche

range of physical and biological conditions under which a species lives (its role in the community)
-how it uses all its resources

human population growth

exponential growth

keystone species

species that exert strong effects on the community
(wolves in yellowstone, coral)

tolerance

range of conditions an organism can survive & reproduce in (can be true for animals, plants, etc.)

neutral relationship

neither species directly affects the other
(fox on grass)

interspecific competition

competition between members of different species for limited supply of resources (food, shelters, mates, etc.)

resource partioning

two species divide a niche to avoid competition
-interspecific competition
-negative effect on both species
(anteaters)

competitive exclusion

two species in the same community cannot share the exact same niche
-interspecific competition
-negative effect on both species
(lion vs hyena)

predator-prey relationship

the interaction between 2 different species where one hunts and feeds on the other
-predator stops the prey from overpopulating

(hunted is prey, hunter is predator)

predation and herbivory

an interaction in which one organism kills another for food
-good for predator, bad for prey
(shark/seal, cat/mouse, panda/bamboo)

symbiosis

species living closely together (interactive relationship)

commenalism

-symbiotic relationship
-good for one species, neutral for the other
(whale/barnacle, bird nesting in a tree)

mutualism

-symbiotic relationship
-good for both species
(bee/flower)

parasitism

-symbiotic relationship
-good for one species, bad for the other
(dog/flea)

succession

a series of predictable events that occur overtime
-an ecosystem is destroyed but comes back

primary succession

ecological succession that begins in an area where no community previously existed
-total destruction

examples of succession not occuring as it normally should

-deforestation
-animal endangerment (hunting)
-maintaining a lawn
-climate change

pioneer species

first species to populate an area during primary succession

secondary succession

type of succession that occurs in an area that was only partially destroyed
-partial destruction

climax community

final stage of succession, in which the community is stable
-collection of most stable organisms (resembling goal of succession)

biodiversity

the variety of life in the world or in a particular habitat or ecosystem
-ecosystem diversity, species diversity, and genetic diversity

why is biodiversity important?

-maintains healthy biosphere
-provides natural resources (food, water, etc.)
-natural services (water purification, pest control, etc.)
-ecosystem resilience (ability to recover after a disturbance

mechanical digestion

physical breakdown of large pieces of food into smaller pieces of food

chemical digestion

breaking of chemical bonds in food by enzymes

accessory organs

food never passes through these organs
-gall bladder
-salivary glands
-liver
-pancreas

oral cavity

(mouth)
-begins mechanical digestion, begins chemical digestion, swallowing
-major secretion is saliva (salivary amylase)
-source of secretion: salivary glands
saliva: acts on all food
salivary amylase: acts on startches

espohagus

assists in moving food from mouth to stomach (peristalsis)

stomach

-mechanical digestion (chyme) & chemical digestion (proteins)
-major secretion is hydrochloric acid, pepsin, & mucus
-source of secretion: stomach
pepsin: enzyme that breaks down proteins
HCl: activates pepsin
mucus: protection

liver

-produces bile (fat digestion) & detoxification
-major secretion is bile
-source of secretion: liver
bile: emulsifies fats (breaks large fat droplets into small ones)

gall bladder

-stores and releases bile
-major secretion is bile
-source of secretion: liver
bile: emulsifies fats (breaks large fat droplets into small ones)

pancreas

-produces enzymes & sodium bicarbonate
-regulates blood sugar
-major secretion is enzymes & sodium bicarbonate
-source of secretion: pancreas
enzymes: carbs, proteins, lipids, and nucleic acid

small intestine

-chemical digestion
-absorbs into blood (villi & microvilli)
-major secretion is bile (liver), enzymes (pancreas & small intestine) & sodium bicarbonate (pancreas)
-source of secretion: liver, pancreas, and small intestine
acts on all food types

large intestine (colon)

-regulates H2O content of waste
-bacteria home

rectum and anus

store, compact, and remove waste

autotroph

organisms that make their own food/glucose
-such as plants

heterotroph

organism that consumes others for food/glucose
-humans, etc.

reflect

to bounce off without absorbing
-color is reflected
-what we see

chlorophyll

a pigment that reflects green

pigments

a substance/molecule that absorbs and reflects light

ATP

the energy cells use

how energy is stored in ATP

in high energy phosphate bonds

how energy is released from ATP

energy is released from ATP by breaking the bonds between the phosphate groups by hydrolysis. when the bond is broken, ATP loses a phosphate group and becomes ADP.

photosynthesis

makes glucose (food) using sun energy

reactants and products of photosynthesis

reactants: carbon dioxide and water
products: glucose and oxygen

photosynthesis equation

CO2 + H2O --> light energy --> C6H12O6 + O2

chloroplast

an organelle found in plant and algae cells where photosynthesis occurs

outer & inner membrane: two membranes
stroma: fluid inside chloroplast
granum (grana): stack of disks
thylakoid: individual disk
thylakoid membrane
thylakoid space: space inside thylakoid

light dependent reactions

converts light energy into more useable energy in a cell (ATP, NADPH)
-location: thylakoids

electron transport chain (photosynthesis)

series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions

light independent reactions (calvin cycle)

makes glucose as a food source
-location: stroma

factors affecting the rate of photosynthesis

light intensity, light wavelength, concentration of carbon dioxide, temperature

cellular respiration

breaks down glucose for energy

reactants and products of cellular respiration

reactants: glucose and oxygen
products: carbon dioxide, water, and ATP

cellular respiration equation

C6H12O6 + O2 --> CO2 + H2O + ATP

mitochondria

powerhouse of the cell, organelle that is the site of ATP (energy) production

matrix: fluid filled
inner & outer membrane
intermembrane space

connection step

continuing the breakdown of glucose (prepares for krebs cycle)
-aerobic
-location: matrix of mitochondria

glycolysis

gain ATP, begins the breakdown of glucose
-anaerobic
-location: cytoplasm

krebs/citric acid cycle

completes the breakdown of glucose into CO2
-aerobic
-location: matrix of mitochondria

electron transport chain (cellular respiration)

use the energy of the e- from glucose to make ATP
-aerobic
-location: inner membrane of mitochondria

lactic acid fermentation

keep glycolysis going when there is no oxygen (2 ATP)
-anaerobic
-location: cytoplasm

alcoholic fermentation

keep glycolysis going when there is no oxygen (2 ATP)
-anaerobic
-location: cytoplasm

anaerobic respiration

does not require oxygen

aerobic respiration

requires oxygen
produces a lot more ATP

organelle

specialized structure that performs important functions within a eukaryotic cell

nucleus

eukaryotic
in animal & plant cells
contains DNA (instructions go make proteins)
control center

nucleolus

eukaryotic
in animal & plant cells
produces ribosomes

nuclear membrane

eukaryotic
in animal & plant cells
controls what goes in and out of the nucleus

nucleoid

prokaryotic
a dense region of free-floating DNA

mitochondria

eukaryotic
animal & plant cells
2 membranes (inner is bigger), has own DNA
cell respiration (food to energy)
capture & release energy

rough endoplasmic reticulum

eukaryotic
animal & plant cells
internal membranes (covered w/ ribosomes)
makes proteins for export

smooth endoplasmic reticulum

eukaryotic
animal & plant cells
internal membranes
makes lipids & detox

ribosome

eukaryotic & prokaryotic
animal & plant cells
makes protiens

cell membrane

eukaryotic & prokaryotic
animal & plant cells
phospholipid bilayer
regulate materials entering/exiting the cell,protection/support

cell wall

eukaryotic & prokaryotic
plant cells only
shape, support, & protection
not selectively permeable

vacuole (animal cell)

eukaryotic
-found in animal cells
-used for storage

vacuole (plant cell)

eukaryotic
-found in plant cells, large & central
-used for storage

vesicle

eukaryotic
plant & animal cells
-used for storage
-membrane-bound sac w/ transport materials
-moving

chloroplast

eukaryotic
plant cells only
2 membranes, chlorophyll (green) has own DNA
photosynthesis (sun energy to food)
capture & release energy

centrioles

eukaryotic
animal cells only
pair of microtubule that organize cell division

cytoplasm

eukaryotic & prokaryotic
animal & plant cells
water-based
support organelles, perform reactions

golgi apparatus

eukaryotic
animal & plant cells
stack of pancakes (vesicles merging)
ships out proteins (modifies, sorts, & packs)

lysosome

eukaryotic
mostly in animal cells
membrane-bound sac w/ hydrolytic enzymes
used to break down materials/digestion

cytoskeleton

eukaryotic
animal & plant cells
microfilaments, microtubules (long proteins)
framework, movement