everything basically Flashcards
define the term clade
a group of organisms that consists of a common ancestor and all its lineal descendants
define ecological niche
the role and space that an organism fills in an ecosystem, including all its interactions with the biotic and abiotic factors of its environment
define keystone species
a plant or animal that plays a unique and crucial role in the way an ecosystem functions
define the term carrying capacity
the size of the population that can be supported indefinitely on the available resources and services of that ecosystem
define the term genome
all the genetic material in the chromosomes of an organism, including its genes and DNA sequences
define the term gene
region/s of DNA that are made up of nucleotides; the molecular unit of heredity
define polygenic inheritance
when one characteristic is controlled by two or more genes
define evolution
change in the genetic composition of a population during successive generations, which may result in the development of new species
define microevolution
small-scale variation of allele frequencies within a species or population, in which the descendant is of the same taxonomic group as the ancestor
define macroevolution
the variation of allele frequencies at or above the level of species over geological time, resulting in the divergence of taxonomic groups, in which the descendant is in a different taxonomic group to the ancestor
identify one example of an interspecific hybrid that does not produce fertile offspring
Mule
identify the features of pioneer species
ability to fixate nitrogen, tolerance to extreme conditions, rapid germination of seeds, ability to photosynthesise
describe the process of making recombinant DNA
isolation of DNA
cutting of DNA (restriction enzymes)
insertion of DNA fragment (plasmid vector)
joining of DNA (DNA ligase)
amplification of recombinant DNA (bacterial transformation)
recall that common assumptions of cladistics
a common ancestry, bifurcation and physical change
recall the structure of DNA
nucleotide composition of deoxyribose sugar, phosphate and nitrogenous base.
Complementary base pairing by weak, base-specific hydrogen bonds between DNA strand.
Adenine = Thymine
Cytosine Ξ Guanine
recall an example of a transcription factor gene that regulates morphology
HOX transcription factor family
recall an example of a transcription factor gene that regulates cell differentiation
Sex-determining region Y
recall how speciation and macroevolutionary changes occur
from an accumulation of microevolutionary changes over time.
what is biodiversity
biodiversity includes the diversity of species and ecosystems
how does biological classification work
biological classification can be hierarchical and based on different levels of similarity of physical features, methods of reproduction and molecular sequences
what do conserved sequences do
conserved sequences (e.g. mitochondrial DNA) are assumed to accumulate mutations at a constant rate over time and, therefore, provide a method for dating divergence.
what are the functions of ‘noncoding’ DNA
many functions of ‘noncoding’ DNA are yet to be determined
what is the purpose of gene expression
the purpose of gene expression is to synthesise a functional gene product (protein or functional RNA); that the process can be regulated and is used by all known life
how is gene expression controlled
differential gene expression, controlled by transcription factors, regulates cell differentiation for tissue formation and morphology
what is the purpose of the application of DNA sequencing
the application of DNA sequencing is to map species’ genomes
what is the purpose of the application of DNA profiling
the application of DNA profiling is to identify unique genetic information
what does evolutionary radiation refer to
evolutionary radiation refers to an increase in taxonomic diversity or morphological disparity
how does natural selection occur
natural selection occurs when the pressures of environmental selection confer a selective advantage on a specific phenotype to enhance its survival (viability) and reproduction (fecundity)
what is mutation the ultimate source of
mutation is the ultimate source of genetic variation, as it introduces new alleles to a population
a large number of chemical mutagens are? and what do they do?
a large number of chemical mutagens are carcinogenic and interact directly with DNA
In eukaryotic cells, DNA is a……..that occurs…………in……….in……in…Is contained within……Is bound to……..Genomes…………Do not contain………………………Are ……. in shape
In eukaryotic cells, DNA is a double-stranded molecule that occurs bound to proteins (histones) in chromosomes in the nucleus and as circular DNA in the mitochondria and chloroplasts
Is contained within a nucleus
Is bound to histone proteins
Genomes contain large amounts of non-coding and repetitive DNA (including introns)
Do not contain plasmids (but organelles such as the mitochondria may contain their own chromosomes)
Are linear in shape
In prokaryotic cells, Dna is…………..Is found………..Is……..Genomes are……..Contains……Is…..in shape.
In prokaryotic cells, DNA is present as unbound circular DNA in the cytosol of prokaryotes
Is found freely in the cytoplasm (within a region called the nucleoid)
Is naked (i.e. not bound with proteins and therefore doesn’t form chromatin)
Genomes are compact (contain little repetitive DNA and no introns)
Contains extra-chromosomal plasmids
Is circular in shape
what does the Linnaean system not rely solely on
the Linnaean system does not rely solely on physical features for classification
Gross inputs of respiration are
Gross inputs of respiration are oxygen and glucose
Gross outputs of respiration are
Gross outputs of respiration are carbon dioxide and water and ATP
Gross inputs of photosynthesis are
Gross inputs of photosynthesis are carbon dioxide and water
Gross outputs of photosynthesis are
Gross outputs of photosynthesis are oxygen and glucose
give examples of biotic limiting factors
Examples of biotic limiting factors of population growth are competition for resources, predation and disease
Give examples of abiotic limiting factors
Examples of abiotic limiting factors of population growth are space, availability of nutrients, pollution, natural disasters, extreme climatic events (drought, cyclones, global temperature
change).
What is symbiosis
Symbiosis is any type of a close and long-term interaction between two different organisms
what does the competitive exclusion principle state
the competitive exclusion principle states that two species that compete for the exact same resources in the same niche cannot stably coexist.
What are keystone species
A keystone species has a disproportionately large effect on its ecosystem relative to its abundance. They can be described as playing an important role in maintaining the structure the community. Such species help to maintain local biodiversity within a community either by controlling populations of other species that would otherwise dominate the community or by providing critical resources for a wide range of species.
What is primary succession
Primary succession occurs in an area without any initial vegetation (bare rock).
What is secondary succession
Secondary succession occurs in an area with initial vegetation (soil already exists).
What is the role the Helicase plays
Helicase unwinds the DNA double helix and separates the strands by breaking the hydrogen bonds between the two complementary strands. Creates a replication fork region so the bases are exposed.
What is DNA polymerase
DNA polymerase forms new complementary strands using each original strand as a template to produce a copy. It adds complementary nucleotides to the exposed bases and also proofreads the strand.The direction of replication is 5’ to 3’.
what does the genotype refer to
Genotype refers to the combination of alleles that an organism has.
How does microevolutionary changes occur
Microevolutionary changes can occur through mutation, gene flow and genetic drift.
What is the process of divergent evolution
Divergent evolution is the process whereby groups from the same common ancestor evolve and accumulate differences, resulting in the formation of new species.
Adaptive radiation is a type of divergent evolution where there is rapid diversification of an ancestral population into several ecologically different species.
What is convergent evolution
Convergent evolution is the independent evolution of similar features in species of different periods in time.
Parallel evolution is
Parallel evolution is the similar development of a trait in distinct species that are not closely related, but share a similar original trait in response to similar evolutionary pressure.
Coevolution is
Coevolution is the influence of closely associated species on each other in their evolution.
Allopatric speciation is
Allopatric speciation is when two populations of the same species become isolated from each other due to geographic changes, finally becoming different species.
Sympatric speciation is
Sympatric speciation is when two groups of the same species live in the same geographic location, but they evolve differently until they can no longer interbreed and are considered different species.
Parapatric speciation is
Parapatric speciation is when the populations that are diverging maintain a zone of contact and do not cease the exchange of genes completely. The species are spatially separated, but still exchange migrants. Nothing is stopping individuals from mixing and mating, but it doesn’t happen. The lower fitness of hybrids drives increased differentiation, eventually resulting in premating isolation.
Without genetic variation…
Without genetic variation, a population cannot evolve in response to changing environmental variables and, as a result, may face an increased risk of extinction.
What are Island populations
Island populations are typically small and isolated, and as a result, inbreeding and reduced genetic diversity elevate their extinction risk.
The process of stratified sampling (6 steps)
The process of stratified sampling
1. purpose (estimating population, density, distribution, environmental gradients and profiles, zonation, stratification)
2. site selection
3. choice of ecological surveying technique (quadrats, transects)
4. minimising bias (size and number of samples, random-number generators, counting criteria, calibrating equipment and noting associated precision)
5. methods of data presentation
6. analysis
An exponential growth pattern…
An exponential growth pattern (J curve) occurs in an ideal, unlimited environment. Tends to be seen in populations that are very small or in regions that are newly colonised by a species
A logistic growth pattern…
A logistic growth pattern (S curve) occurs when environmental pressures slow the rate of growth. Will eventually be seen in any stable population occupying a fixed geographic space
