BIOLOGY HALF VOCAB

VOCAB

Homeostasis

process by which organisms maintain a relatively stable internal environment

biotic factors

All the living organisms that inhabit an environment

abiotic factors

Nonliving components of environment.

Prokaryotic cell

cell that does not have a nucleus or other membrane-bound organelles; ONLY BACTERIAS

Eukaryotic cells

Contain a nucleus and other organelles that are bound by membranes; plants, animals, fungus, protists

endosymbiotic theory

a theory that states that certain kinds of prokaryotes began living inside of larger cells and evolved into the organelles of modern-day eukaryotes

selectively permeable

a property of cell membranes that allows some substances to pass through, while others cannot

fluid mosaic model

model that describes the arrangement and movement of the molecules that make up a cell membrane

polarity of water

water is a polar molecule meaning it has opposite charges on opposite ends. This causes hydrogen bonds to form causing water to stick together.

Cohesion

water being attracted to other water molecules

Adhesion

water being attracted to OTHER substances that are not water (ex. your skin, plant leaf)

surface tension

the result of cohesion; the surface of bodies of water have a "tension" across them; allows insects to walk on water

Cappilary action

when cohesion and adhesion work together to move water UP against gravity; how plants get water from their roots to their leaves in osmosis

diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration. Type of passive transport (no energy required).

osmosis

Diffusion of water through a selectively permeable membrane; passive transport; no energy required; goes WITH the concentration gradient

hypertonic solution

Solute concentration in the solution outside the cell is GREATER than the solute concentration inside the cell; cell LOSES water (shrinks)

hypotonic solution

Solute concentration in the solution outside the cell is LESS than the solute concentration inside the cell; cell GAINS water (swells)

isotonic

Having the same solute concentration in both solutions (cell stays same size because water moves in and out equally)

dynamic equilibrium

water concentrations are equal; water moved both in and out of the cell equally

facilitated diffusion

process of diffusion in which molecules pass across the membrane through cell membrane channel proteins (passive \-- no energy required)

active transport

Energy-requiring process that moves material across a cell membrane against the concentration gradient

Exocytosis

process by which a cell moves material out of the cell using a vesicle which merges with the cell membrane to release material; requires energy; active transport

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane to create a vesicle; requires energy; active transport

enzyme

a protein that speeds up a chemical reaction by reducing activation energy

substrate

the reactant(s) that bind to the active site of an enzyme (fits together like a lock and key)

active site

the region on an enzyme where substrates bind during a reaction

activation energy

the amount of energy required to start a reaction

synthesis reaction

when 2 or more substrates are combined to make 1 product

decomposition reaction

when 1 substrate is broken down into 2 or more products

macromolecule

biomolecules; large molecules necessary for life (proteins, carbohydrates, lipids, nucleic acids

karyptype

an organized picture of an organism's chromosomes; chromosomes are in homologous pairs; last pair are sex chromosomes

monosomy

when there is only 1 chromosome present instead of 2 for that pair (ex. Turner's Syndrome)

trisomy

when there are 3 chromosomes present instead of 2 for a pair (ex. Down Syndrome)

allele

a form of a trait (ex. hair color, there is a brown allele, blonde allele, black allele, red allele, etc)

phylogenetic tree

A branching diagram that uses DNA evidence to show the evolutionary history of a group of organisms;

clade

an area of the phylogenetic tree that includes the common ancestor and all its descendants

monomer

A simple compound whose molecules can join together to form polymers; building block

polymer

A long molecule consisting of many monomers linked together.

dehydration synthesis

water is removed in order to build polymers from monomers

hydrolysis reaction

water is added to break apart polymers

autotroph

An organism that makes its own food (ex. plants)

heterotroph

An organism that cannot make its own food and must consume it (ex. animal)

decomposer

break down wastes into their nutrient level (ex. bacteria, fungi)

herbivores

Consumers that eat only plants

Omnivore

An animal that eats both plants and animals

Carnivore

A consumer that eats only animals.

food chain

A series of steps in which organisms transfer energy by eating and being eaten

food web

A community of organisms where there are several interrelated food chains

exponential growth

the population size is growing rapidly; know as a "J" curve

logistic growth

population growth that starts with a period of exponential growth, but then levels off to a carrying capacity due to limiting factors; know as an "S" curve

carrying capacity

Largest number of individuals of a population that a environment can support based on limiting factors (ex. availability of food, water, shelter, space)

limiting factors

any factor that controls the growth of a population (ex. availability of food, availability of mates, disease, etc. )

predation

when one organisms hunts, kills, and eats another organism (predator-prey)

competition

when 2 organisms "fight" for the same resource (ex. a deer and a rabbit both eat grass)

interspecific competition

competition between two different species

intraspecific competition

competition between members of the same species

selective pressure

any outside/external force that causes a population to evolve

DNA fingerprint

DNA fragments separated by size using gel electrophoresis; can be used to determine paternity, solve a crime, identify a body, etc.

adaptation

anything that increases an organism's ability to survive

niche

An organism's particular role in an ecosystem; includes feeding relationships; where and how it lives; any special characteristics/behaviors (e. seed disperser)

niche partitioning

the process of organisms dividing up a resource into different niches; increases the biodiversity of an area

competitive exclusion principle

Ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time (one species with either move out or die off)

keystone species

a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.

cell cycle

series of events that cells go through as they grow and divide; INTERPHASE (G1, S, G2), MITOSIS (PMAT), CYTOKINESIS

mitosis

a type of eukaryotic cell division during which the cell nucleus divides (Prophase, Metaphase, Anaphase, Telophase); used to create genetically identical daughter cells

somatic cells

body cells, diploid

gametes

sex cells, haploid

meiosis

a type of eukaryotic cell division that results in four daughter cells each with half the number of chromosomes of the parent cell; produces gametes (PMAT 1 and PMAT 2)

haploid cell

A cell containing only one set of chromosomes (n). In human gametes: 23 chromosomes.

diploid cell

A cell containing two sets of chromosomes (2n), one set inherited from each parent. In human somatic cells: 46 chromosomes or 23 pairs.

cytokinesis

Division of the cytoplasm during cell division

homologous pairs

A pair of chromosomes of the same type and size that code for the same genes; one from each parent.

heterogygous

An organism that has two DIFFERENT alleles for a trait (ex. Rr or Mm)

homozygous

An organism that has two of the SAME alleles for a trait (ex. RR or rr or MM or mm)

phenotype

An organism's physical appearance, or visible traits.

genotype

an organism's genetic make up, or combination of alleles

crossing over

Process in which homologous chromosomes exchange portions of their chromatids during prophase 1 of meiosis.

Non-disjunction

Error in meiosis in which homologous chromosomes (anaphase 1) or sister chromatids (anaphase 2) fail to separate correctly; results in monosomy or trisomy

Nitrogren Cycle

Series of steps in which nitrogen cycles from the atmosphere, to the soil, into plants, and back into the atmosphere changing form along the way

nitrogen fixation

bacteria in soil convert (or "fix") atmospheric nitrogen into a usable form for plants to assimilate (take up) into their roots

transpiration

Evaporation of water from the leaves of a plant

Evaporation

The change of a substance from a liquid to a gas

Precipitation

Any form of water that falls from clouds and reaches Earth's surface.

seepage

when water seeps into the ground and slowly moves deeper underground; can form groundwater

Groundwater

water that fills the cracks and spaces in underground soil and rock layers

Runoff

water that flows over the ground surface from areas of higher elevation to lower elevation; often runs into stream, rivers, lakes, ocean rather than soaking into the ground

weathering

when wind and water work together to break down rocks and sediment (ex. this is how phosphorus in rock ends up getting into soil and then into plants)

purpose of mitosis

To make somatic cells to repair or replace cells or form growth

purpose of meiosis

To make gamete cells (sperm/egg) for sexual reproduction

primary consumer

An organism that eats producers (aka herbivore)

secondary consumer

An organism that eats primary consumers

enzyme-substrate complex

A temporary complex formed when an enzyme binds to its substrate molecule(s).

density dependent factors

factor that limits population MORE more as population density increases (ex. availability of food or water, amount of predators, disease, availability of nitrogen for plants)

density independent factors

limiting factors whose influence is not affected by population density (ex. natural disasters like fire or climate change)

mutation

a random change in a DNA sequence that affects genetic information and can lead to a new phenotype

characteristics of living things

1.cells 2.reproduction 3.genetic code 4.growth & development 5.use energy 6.response to environment 7.internal balance/homeostasis 8.evolution

levels of organization in the body

cell, tissue, organ, organ system, organism

levels of organization in ecology

organism, population, community, ecosystem, biome, biosphere

function of proteins

1. build organisms (ex. hair/skin/muscle)
2. enzymes (speed up chemical reactions)
3. transport materials (ex. integral proteins in cell membrane)
4. hormones

function of lipids

1. long term energy storage
2. cell membranes (phospholipid)
3. insulation
4. cushioning