A3.1 - Diversity of organisms + A3.2 Flashcards
(29 cards)
Define an orgnanism (2)
biological system that functions as an individual life form
composed of cells
Define a population (3)
group of organisms of the same species in same area
rely on same resources
interbreed + interact with each other
Define a community (2)
populations of multiple different species
occupying same geographical locations at same time
Define variation
differences between members of a group
Define discrete variation (3)
traits that can be put into distinct quantitative categories
influenced by one or few genes
e.g blood type, eye colour, dominance
Continuous variation (4)
traits that vary along a quantitative continuum
results from complex interactions between many different genes
environment often plays a significant part in phenotype expression
e.g height, body mass
Causes of variation within a species (4)
mutation
gene flow
meiosis
sexual reproduction
Define morphological concept of species (2)
classifying organisms based on physical traits
used for extinct species
Binomial nomeclature (2)
first part : genus
second part : species
Limitations of biologocial calssification of species based on reproduction (4)
existence of asexual reproduction
not possible for extinct species
limitations of environments of species
potentially interfering with species behaviour
Define speciation
formation of new/distinct species due to evolution
Process of divergence during speciation (4)
develop mutations different from each other
become more different to each other as they become more compatible to the environment they are in
become more genetically different
to the extent where they cannot reproduce with each other –> become separate species
Difficulties with speciation (2)
difficult to find exact point where they become separate species
hybrids could be created by 2 divergin species
Differences between species chromosomes (3)
length - number of base pairs
position of centromere
genes at certain locus (location)
Define karyogram (2)
diagram/photograph of chromsomes in nucleus
arranged in homologous pairs of decreasing length
Define karyotype
complete set of chromosomes in cell
Evidence for chromosome 2 fusion from chimp chromosomes (3)
banding of human chromosomes matches 2 separate chromosomes in apes
supposedly fused chromosome has telomere sequences in the middle + end
human chromosome 2 has an inactive centromere
Define genome
whole genetic information of an organism
Pseudogenes (2)
non-coding gene regions
leftovers from genes experiencing too much SNPs
System of species classification (8)
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Domain in species classification
DNA contained in nucleus
Kingdom in species classification
organism that ingests food, digests it + assimilates it
Define taxonomy (2)
the classification of living things based on similarities + differences
study relationships between different organisms
Benefits of species classification (3)
communication of biological info between scientists
species in same group likely share a common ancestor - info. on how species evolved
characteristics of individual species in a group can be predicted if the group’s characteristics is known
