ib bio y1 (cry)

Functions of life

Functions of life

Metabolism

Reproduction

Sensitivity

Homeostasis

Growth

Response

Excretion

Nutrition

surface area to volume ratio

as organisms increase in size, their SA:V ratio decreases

differentiation

in complex multicellular organisms eukaryotic cells become specialized for specific functions as certain genes are expressed

stem cell

a cell which can divide an unlimited number of times and can differentiate into more specialized cells

totipotent

stems cells which can differentiate into any cell type, found in an embryo and the placenta

pluripotent

stems cells which can differentiate into some cell types, found in bone marrow

multipotent

stem cells which can only differentiate into closely related cell types, found in the umbilical cord

unipotent

stems cells which can only differentiate into their own lineage, found in adult organ tissues

magnification

image size/ actual size

endosymbiotic theory

to overcome a small surface area to volume ratio ancestral cells developed folds in their membrane, larger anaerobically respiring prokaryotes engulfed smaller aerobically respiring prokaryotes

Prokaryotic cell structure

small, simple cell structures that have no nucleus and reproduce by binary fission

Eukaryotic cell structure

larger, more complex cells with numerous membrane bound organelles reproducing by mitosis or meiosis

plasma membrane

a membrane controlling the exchange of materials in and out of the cell, formed from a phospholipid bilayer

nucleus

double membrane containing chromatins and the site of ribosome production

rough endoplasmic reticulum

continuous folds of the membrane called cisternae covered in ribosomes and the site of protein synthesis

Ribosomes

a complex of rRNA and proteins found in the cytoplasm which synthesize proteins

Mitochondrion

the site of aerobic respiration which are surrounded by a double membrane containing enzymes, producing ATP

Golgi apparatus

contains flattened membrane sacs which modifies proteins and lipids before packing them into vesicles

lysosome

a specialized form of vesicles containing hydrolytic enzymes used to break down waste and the immune system

chloroplast

contain membrane-bound compartments called thylakoids containing chlorophyll stacks to form grana.

phospholipids

the basic structure of the membrane formed by a hydrophilic phosphate head bonding to two hydrophobic fatty tails

simple diffusion

the net movement as a result of random motion of molecules down a concentration gradient

active transport

the movement of molecules and ions through a cell membrane against the concentration gradient using energy from respiration

endocytosis

the process by which plasma membrane engulfs materials forming a small sac called an endocytic vacuole.

exocytosis

the process by which materials are transported out of cells as substances are packed into secretory vesicles in the golgi apparatus, fuse with the surface cell membrane and are released.

mitosis

a regulated sequence of events that occur between once cell division and the next.

Interphase

the longest and most active phase during which a cell will increase in mass and size, synthesize proteins and begin replicating DNA

cyclin D

present first triggering a cell to move from G1 to S phase

cyclin E

highest concentration at the start of S phase preparing a cell for DNA replication

cyclin A

highest concentration in G2 phase activating the cell for mitosis and DNA replication

cyclin B

highest concentration at beginning of mitosis promoting the formation of the mitotic spindle

prophase

chromosomes condense and the two centronomes move towards opposite poles as spindle fibers begin to emerge and the nuclear envelope breaks down

metaphase

centronomes reach opposite poles as the chromosomes line up at the equator and spindle fibers reach and attach.

anaphase

sister chromatids separate and the spindle fibers begins to shorten pulling the chromosomes to opposite poles

telophase

chromosomes arrive at poles and decondense as a nuclear envelope reforms around each set and nucleoli form within each nucleus

mitotic index

number of cells with visible chromosomes/ total number of cells

limiting factor

a component of an ecosystem which limits the contribution or number of a population

biotic factors

interactions between organisms (intraspecific) and between species (interspecific)

abiotic factors

environmental conditions such as light, pH, rainfall and salinity

law of tolerance

proposes that populations have optimal survival conditions that fall within critical maximum and minimum thresholds as a population is exposed to the extremes of a particular limiting factor

optimal zone

the central portion of the law of tolerance curve which has conditions that favor maximal reproductive success and survivability

zones of stress

regions on the law of tolerance curve which flank the optimal zone where organisms can survive but with reduced reproductive success

zones of intolerance

the outermost regions on the law of tolerance curve in which organisms cannot survive

ecological niche

describes the functional position and role of an organism within it’s environment

competitive exclusion

one species uses the resources more efficiently, driving other species to local extinction

resource partitioning

both species alter their use of the habitat to divide resources between them

fundamental niche

the entire theoretical set of conditions under which an organism can survive and reproduce

realized niche

a set of conditions used by an organism after including interactions with other species

mutualism

a type of symbiosis where both species benefit from the interaction

commensalism

a type of symbiosis where one species benefits and the other is unaffected

parasitism

a type of symbiosis where one species benefits to the detriment of the other

biomass

the total dry weight of organic matter in organisms or ecosystems

primary productions

the production of chemical energy in organic compounds by producers

Gross Primary Production (GPP)

the amount of chemical energy as biomass that a producer creates in a given length of time

Net Primary Production (NPP)

the amount of chemical energy that is not consumed by respiration

secondary production

the generation of biomass by heterotrophic organisms driven by the transfer of organic compounds

closed ecosystem

ecosystem which exchanges energy but not matter

open ecosystem

an ecosystem which exchanges both energy and matter with it’s surrounding environment

primary succession

occurs when communities develop on entirely new land without any established soil

endemic species

species which are native to a defined geographic region

alien species

species which have been transferred from their natural habitat to a new environment

invasive species

if an introduced alien species has a detrimental effect upon the pre-existing food chains

cane toads

an invasive species introduced into Australia in 1935 to control the the spread of the sugar cane beetle which was damaging crops which now endangers native wildlife

physical control

controlling the population of an invasive species through manual or mechanical removal or restriction

biological control

controlling the population of an invasive species using a living organism (or virus)

chemical control

controlling the population of an invasive species through the use of chemical agents

biomagnification

the process in which chemical substances become more concentrated at each trophic level

bioaccumulation

the build up of a chemical substance in the tissues of a single organism

indicator species

species which are sensitive to specific environmental conditions whose growth or reduction indicates changes to the environment

biotic index

compares the relative frequency of indicator species and provide an overall assessment of environmental health

biodiversity

the variety and variability of all living organisms within a given ecological area

Simpson’s reciprocal index

a measure of the relative biodiversity of a given community

evolution

the changes of heritable characteristics of organisms over generations

heritable characteristics

characteristics that can be inherited by the next generation

speciation

the evolution of a new species from an existing one

allele frequencies

the number of times an allele occurs within a gene pool in populations change over time

fossils as evidence of evolution

can be used to tell organisms have changed significantly over time and can be dated and sequenced to show evidence for transitional species

selective breeding as evidence of evolution

showcases the ability to increase expression of characteristics over many generations

variation

differences which exist between organisms of the same species

mutation

source of genetic variation through a change in the DNA base sequence resulting from copying an error during DNA replication and creating a generation of new alleles

crossing over during meiosis

the process by which homologous chromosomes exchange alleles as non-sister chromatids can cross over and get entangled and can result in a new combination of alleles

random orientation

occurs due to the independent arrangement of homologous pairs along the equator of the cell during metaphase

adaptations

characteristics that cause individuals to be well suited to their environment and methods of living

natural selection

the process by which organisms that are better adapted to their environment to survive, reproduce, and pass on their advantageous alleles, to increase in frequency within a population

binomial system

the biological system of naming used to name species according to their taxa

classification structure mnemonic

Do: Domain

Kinky: Kingdom

People: Phylum

Come: Class

Over: Order

For: Family

Great: Genus

Sex: Species

Bryophytes

small terrestrial plants that have no vascular tissue and reproduction takes place via spores, which have rhizoids instead of roots

filicinophytes

ferns which contain vascular tissue as well as roots, stems and leaves which reproduce via spores distributed on the underside of fronds called sporangia

coniferophytes

tall, straight trees commonly known as conifers which reproduce using pollen and ovules

angiospermophytes

flowering plants with roots, stems as well as vascular and cambium tissues who’s flowers produce pollen and contain ovules

porifera

simple aquatic organisms consisting of a colony of cells, commonly known as sponges supported by silica or calcium formations called spicules.

cnidaria

aquatic organisms with a body cavity surrounded by two layers of cells with a single opening for both ingestion and egestion

platyhelminths

flat bodied, unsegmented worms which are sort and lack a circulatory system or skeletal structure

annelida

round bodied, segmented worms with a ring-shaped body with a separate mouth and anus

mollusca

a diverse group of animals including snails, slugs, mussels and limpets with a muscular foot and separate openings for mouth and anus

arthropoda

animals with segmented bodies, a hard exoskeleton and usually one pair of jointed limbs per body segment

chordata

all vertebrates, having a notochord, a hollow nerve chord, a series of pharyngeal slits and a tail which extends beyond the anus

clade

a group of organisms that have all descended from a common ancestor

homologous traits

characteristics which may differ in form and function in species but that have a shared evolutionary origin