Biology S6 things that might be useful for the bac

Stuff from s6 that might be useful for bac- not thorough but things i will likely forget Done: 6.3.2 Polygenic characters, 6.3.1 DNA, 6.4 Ecology Left: 6.3.3 Evolution

Phosphorelated intermediate definition

What is created during phosphorylation in energy coupled reactions with ATP

more detail: how ATP participates in mechanical work

ATP binds noncovalently to motor proteins and then is hydrolyzed

Example of ATP as a cofactor + brief description

Na+/K+ ATPase pump, a pump that pumps solutes against the concentration gradient- Na+ from the cytoplasm (low conc.) to the extracellular fluid (high conc.), K+ from the extracellular fluid to the cytoplasm

LAW OF INDEPENDENT ASSORTMENT​

Each of a pair of alleles for a particular gene can combine randomly with either of another pair of alleles for different gene.​

Epistasis definition

a gene at one locus alters the phenotypic expression of a gene at a second locus​

Quantitative characters definition

those that vary in the population along a continuum​

Events unique to meiosis (that occur in meiosis I) (3)

Synapsis and crossing over in prophase I: Homologous chromosomes physically connect and exchange genetic information​
At the metaphase plate, there are paired homologous chromosomes (tetrads), instead of individual replicated chromosomes​
At anaphase I, it is homologous chromosomes, instead of sister chromatids, that separate​

bivalent definition

a synapsed pair of homologues

tetrad definition

consists of the 4 chromatids of a homologous pair

Crossing over definition

the exchange of material between homologous chromosomes during prophase I of meiosis resulting in a new combination of genes

chiasma definition

a random contact point between non-sister chromatids

Aneuploidy definition

the addition or loss of individual chromosomes. Generally 1, sometimes 2

Polyploidy (euploidy) definition

when the chromosome number is increased through the addition of one or more complete haploid sets

When analysing a family tree what has to be the case to be sure that it is a recessive X-linked trait?

Females must have an affected father

When analysing a family tree what has to be the case to be sure that it is a dominant X-linked trait?

males must have an affected mother and females must have at least one of the parents affected

3 steps of PCR cycle described

Denaturation: DNA  is heated ( 90 to 100 °C) to denature = to separate the DNA strands​
Annealing : rapid cooling  ( 50 to 65°C) allows annealing (hydrogen bonding) of short single- stranded DNA primers​
Extension : a moderate heating ( 65 to 75°C) allows the replication of DNA by the DNA polymerase in the direction 5´-3´

Restriction endonucleases definition

enzymes that cut DNA at a restriction site near or overlapping a specific base sequence called recognition sequence, that is a palindromic sequence (symmetrical to its complementary)

DNA ligase function

form permanent bonds between restriction fragments with complementary sticky ends, that could come from a different organism

Biosphere definition

Global ecosystem, sum of all the planets ecosystems

Biotic factors that affect the distribution of organisms

predation, herbivory, competition

Abiotic factors that affect the distribution of organisms (5)

Temperature, water, sunlight, wind, rocks and soil

Ecological niche definition

The total of a species use of biotic and abiotic resources, the organisms ecological role

Biological community definition

an assemblage of populations of various species living close enough for potential interaction.  All life/populations in an area.​

Competetive exclusion principle description

Two species competing for the same limited resource cannot coexist in the same space (1 species per niche)

Types of interspecific interactions (7)

Competition, predation, herbivory, symbiosis, parasitism, mutualism, commensalism

predation definition

one species, the predator, kills and eats the other, the prey

Camoflage in biological terms

Cryptic coloration

Aposematic coloration description

Bright warning coloration

What is it called when a harmless species mimics a harmful one

Batesian mimicry

Herbivory description

a herbivore eats parts of a plant or alga.​

Symbiosis description

a dependency relationship where two or more species live in direct and intimate contact with one another, based one or some combination of the following benefits:​ Nutrition (food, water)​, Protection​, Reproduction​

Parasitism description

the parasite, derives nourishment from another organism, its host, which is harmed in the process, eg wasp eggs on the back of a caterpillar

two types of parasites

Endoparasites (live in the body of the host), ectoparasites (live on the external surface of the host)

Mutualism description

benefits both species, eg insects and flowers, can be: Obligate (where one species cannot survive without the other) or Facultative (both species can survive alone)

Commensalism description

One species benefits while another is apparently unaffected, rare, eg birds building nests in trees

Competition description

two or more species compete for a resource in short supply- cannot coexist in the same community, both species are harmed

Demagraphy definition

Study of vital statistics of a population and how they change over time

Life table definition

Age-specific summary of the survival pattern of a population

Survivorship curves types + description

Type I: low death rates during early and middle life, then an increase among older age groups​
Type II: the death rate is constant over the organism’s life span
Type III: high death rates for the young, then a slower death rate for survivors​

semelparity definition

aka big-bang reproduction, species that, reproduce once and die.​

iteroparity definition

Species that produce offspring repeatedly

When does zero population growth occur?

When birth rate = death rate

Components of biodiversity (3 + 2)

genetic (total number of genetic characteristics in a species); species- richness (number of different species), evenness (relative abundance); habitat (number of habitats)

Ecology: relative abundance definition

The proportion each species represents of the total individuals in the community

Two key factors that affects a communities species diversity + explanation

Lattitude (highest in the tropics, lowest in the poles) and area

how can we reduce the global loss of biodiversity (3)

Ecological protection, restoration of ecosystems, reducing habitat fragmentation (by eg creating green corridors)

categories of ecosystem services (4)

Supporting (necessary for the functioning of other ES, eg nutrient cycling), provisioning (products obtained directly from ecosystems for basic human needs, eg food, water, shelter), regulating (benefits from the regulation of ecosystem processes, eg. climate regulation, water purification), cultural (non-material benefitrs from ecosystems, eg. parks)

Two criteria to distinguish ecosystem services from other ecosystem conditions or processes

must be linked to an identifiable set of human beneficiaries, physical and institutional access constraints must not prevent people from realizing those benefits