IB Biology Year 1 Review

ecology

the study of relationships between living organisms and between organisms and their environment

ecosystem

a system made up of organisms as well as the abiotic factors in the area

population

a group of organisms of the same species who live in the same area at the same time

community

a group of populations living and interacting with each other in an area

species

a group of organisms which can interbreed and produce fertile offspring

habitat

the environment in which a species normally lives or the location of a living organism

autotrophs

producers; they can make their own food

heterotrophs

consumers; they feed on ready made organic material

detritivores

organisms that feed on the detritus and decomposing organic material of living organisms

saprotrophs

decomposers; organisms that feed on dead organisms and products of living organisms

carrying capacity

the maximum number of organisms of a species, or the maximum population size which an environment is able to support

random sample

a sample where every individual in a population has an equal chance of being chosen

trophic level

Position in the food chain, determined by the number of energy-transfer steps to that level; a functional classification of taxa within a community that is based on feeding relationships

standard deviation

used to summarize the spread of values around the mean; ∑((X-X)²/n-1)

species

a group of organisms with similar characteristics, which can interbreed and produce fertile offspring

evolution

change in a gene pool of a species over a period of time

organelle

a discrete structure within a cell, and has a specific function

magnification

measure size of diagram ÷ actual size of object

tissue

an integrated group of cells that share structure and are adapted to perform a similar function

organ

a combination of two or more tissues which function as an integrated unit, performing one or more specific functions

organ system

a group of organs that specialize in a certain function together

diffusion

movement of particles from an area of higher concentration to an area of lower concentration down a concentration gradient

osmosis

passive movement of water molecules from a region of lower solute concentration to a region of higher solute concentration across a semi permeable membrane

organic

molecules containing carbon that are found in living systems (Not CO2); often have covalent bonds

enzyme

a globular protein that accelerates a specific reaction; catalysts that can be used over and over

active site

the region of an enzyme surface that binds to the substrate during the reaction catalyzed by the enzyme

denaturation

a structural change in a protein that results in a loss of its biological properties

degenerate

more than one codon can code for a single amino acid

universal

codes are the same for all living organisms

gene

a heritable factor that controls a specific characteristic consisting of a length of DNA occupying a specific position on a chromosome called a locus

genome

the total genetic material of an organelle, organism, or cell

gene mutation

a change in the base sequence of a gene

phenotype

the characteristics of an organism

cell respiration

the controlled release of energy in the form of ATP from organic compounds in cells

food chain

a linear and simple feeding relation, where one organism has one type of food and is eaten by one type of organism

food web

more complex than a food chain and it includes a larger variety of organisms, Each of which feed on a variety of other organisms and they are in turn fed on by more organisms

greenhouse effect

a NATURAL PHENOMENON that was required for life to form on the planet

energy flow (in a food chain)

energy losses between trophic levels include material not consumed or material not assimilated and heat loss through cell respiration

population size factors

if (natality + immigration) > (mortality + emigration) then a population is increasing

exponential phase

occurs when there are no controlling factors

transitional phase

the birthrate begins to decrease

plateau phase

occur as carrying capacity is reached

density dependent factors

more effect in crowded populations (predation and disease)

density independent factors

independent of population size (weather, natural disasters)

prokaryotes

unicellular organisms lacking a nucleus and other membrane-bound organelles; circular DNA

vacuole

a tiny cavity filled with fluid in the cytoplasm of a cell

all cells

Reproduce by binary Fusion

Pili

Cause genetic exchange in Prokaryotes

Fagellum

Create movemeant in Prokaryotes

Plasma Membrane

the outer "Border" in Prokaryotes Controls what enters and leaves the cell

Nucleotide

DNA with No Protien Attached found in Prokaryotes

Ribosomes (Prokaryote)

10s in size (small) :Assemble proteins - connect amino acids together

Cell wall

protection + Structure

Golgi Apparatus

proteins and exports them to where they are needed in eurkaryotes

Cytoplasm

medium for chemical reactions in Eurkaryotes

Nucleus

contains DNA found in Eurkaryotes

Ribsomes (Eurkaryote)

assemble Proteins (string amino acids Together) 80s (bigger) in size Found in Eurkaryotes

Lymsomes

Emzymes break down things (worm out cell part or food) Found in Eurkaryotes

Mitochondria

supplies energy as ATP Found in Eurkaryotes

RER

shapes proteins Found in Eurkaryotes

Uracil

Nucleotide that replaces "thymine" in RNA

Ribose

Sugar that replaces "deoxyribose" in RNA

RNA

Single-stranded nucleic acid

mRNA

Carries copies of genes from the nucleus to the cytoplasm

Ribosome

Where proteins are assembled

rRNA

Type of RNA found in ribosomes

tRNA

Type of RNA that carries each amino acid to ribosome

Transcription

The process of converting DNA to RNA

Translation

The process of converting RNA to proteins

RNA Polymerase

Enzyme that makes strands of RNA from DNA

Codon

Three-letter "word" of RNA

Amino acid

Monomer of proteins (polypeptides)

Peptide bond

Type of bond found between amino acids

Anticodon

Three unpaired bases found at one end of a tRNA

Thymine

Nucleotide that is replaced by "uracil" in RNA