Biodiversity and Natural Resources Flashcards
3 types of adaptation
behavioural
anatomical
physiological
define behavioural adaptation
actions by organism
define anatomical adaptation
observed structures of organism
define physiological adaptation
internal workings of organism
define allele frequency
number between 0-1 showing proportion of an allele within a population
define evolution
change in allele frequency over time
define natural selection
process by which evolution happens
1st step of natural selection
genetic variation due to random mutations (creates new alleles)
2nd step of natural selection
sexual reproduction creates new allele combinations
3rd step of natural selection
environmental change creates a selection pressure giving advantageous phenotype a competitive advantage
4th step of natural selection
individuals with advantageous phenotype are more likely to survive and reproduce passing on advantageous alleles
(alters allele frequency)
factors for rate of change in allele frequency
strength of selection pressure
size of gene pool
organisms’ reproductive rate
importance of variation
population is more resistant to environmental condition changes
ways allele frequency can cgange
natural selection- caused by selection pressure
sexual selection- caused by mating preferences
gene flow- caused by migration
genetic drift- caused by chance
rules for the Hardy-Weinberg principle
no selection pressure
no migration
no mutations
random mating
large population
what does the Hardy-Weinberg principle apply to
genes with 2 alleles- 1 dominant and 1 recessive
Hardy-Weinberg principle equations
p + q = 1
p^2 + 2pq + q^2 = 1
what does p^2 represent
homozygous dominant frequency
what does q^2 represent
homozygous recessive frequency
what does 2pq represent
heterozygous frequency
5 kingdoms
animals
plants
fungi
protists
prokaryotes
3 domains
eukaryotes
archaea
bacteria
classification order
kingdom
phylum
class
order
genus
species
define molecular phylogeny
study of the similarities and differences in DNA/RNA base sequences and/or amino acid sequences in proteins to determine evolutionary relationships between organisms
how did molecular phylogeny provide evidence for the 3 domains
showed the 4 eukaryote are closer evolutionary than types of prokaryotes
plant adaptations
support- xylem and sclerenchyma
chemical defence
seed production
human uses of plants
fibres eg: fabrics
medicines
cosmetics
food
structure and function of cell wall
made from cellulose
contains pits and middle lamella
strength and support
what are pits
thin sections of the cell wall
vacuole
filled with water ions and sugars
single membrane (tonoplast)
keeps cell turgid
structure and function of chloroplasts
double membrane
contain fluid
contain circular DNA
photosynthesis
name of chloroplast internal membrane
thykaloid
name of chloroplast fluid
stroma
structure and function of amyloplasts
double membrane
store amylopectin
difference between plasma membrane in animals and plants
continuous in plant cells (plasmodesmata)
structure of cellulose
unbranched, straight chains of beta glucose (microfibrils)
lattice structure due to hydrogen bonds between chains
properties of cellulose
insoluble
strong
hard to digest
high tensile strength (hard to stretch)
define microfibrils
bundles of beta glucose chains
why is cellulose strong
microfibrils laid parallel or at different angles
pectin and hemicelluloses (short-chained polysaccharides) embedded in fibres
