Topic 4 Ford Flashcards
Adaptation
A feature which helps an organism survive. Can be behavioural, physiological or anatomical
Behavioural
actions by organism
Physiological
features of the internal workings of organisms
Anatomical
structures you can see when you observe or dissect an organism
Biodiversity
The variety in living organisms
Biodiversity - species diversity
measure of the number of different species present in a particular habitat
Biodiversity - genetic diversity
diversity within a species
Biodiversity - ecosystem diversity
a wide range of different habitats in an area
Community
All the living organisms found in a particular place at a particular time
Ecosystem
All the organisms living in a particular area as well as the non-living features of their environment
Endemic species
A species restricted to one geographical area and not found in any other area
Gene
Sequence of nucleotides on a chromosome which codes for the sequence of amino acids in a polypeptide chain
Gene Flow
passing of genes/alleles from one member of a species to another
Gene locus
position of a gene on a chromosome
Gene pool
all the alleles of all the genes present within a population
Genetic diversity
- the number of different alleles within a population/ gene pool
- greater variation of genotypes - more genetically diverse (more heterozygotes)
Habitat
the particular place, with a distinct set of conditions, where a community of organisms is found
Niche
the precise role of an organism withing its environment; what it does, where it lives etc. No two species have the same ecological niche
Population
A group of individuals belonging to one species - generally found in the same place at a time and are able to breed with each other
Speciation
formation of a new species
Species
a group of organisms with a similar morphology, physiology and behaviour which can interbreed to create fertile offspring
Species richness
the number of different species within a habitat at any one time
Morphology
look at appearance
Molecular phylogeny
look for similarities in DNA, RNA and proteins between two species
Ecological niche
the way that an organisms exploits its habitat
Adapted
when an organism is specialised to suit the ecosystem it lives in
Co-adaptations
adaptations of two organisms hat evolve in tandem and become dependent on each other for survival
What is natural selection?
when organisms become adapted so they have a unique ecological niche
What will happen if 2 species occupy the same niche?
they will have to compete until one out-competes the other
How does evolution come about?
by random genetic variation, natural selection and survival of the fittest
Allele frequency
the number of times a specific allele exists in a population
When can the Hardy-Weinberg principle be applied?
If the population is:
- large
- has random mating
- no mutations
- no emigration or immigration
- experiences no natural selection
What does the speed at which a population evolves depend on?
- strength of the selection pressure
- size of the gene pool
- reproductive rate of organisms
Evolution
a change in allele frequency over time
King Prawn Curry Or Fat Greasy Sausages
Kingdom, Phylum, Class, Order, Family, Genus, Species
What makes up the binomial name?
the latin version of the Genus for the 1st word and the latin for the species for the 2nd - Genus has a capital letter whereas species has a lower case
What did Carl Woese do?
- worked on evolutionary relationships between groups of bacteria using RNA sequencing
- He noticed that one group (methanogens) had very different sequences from other bacteria
- He proposed the idea of having 3 domains: Archaea, Bacteria and Eukaryotes
How did Carl Woese go about sharing his ideas?
- He made observations, collected evidence
- Then published his research in a peer reviewed scientific journal and spoke at conferences
How do you measure species richness?
count the number of different species
How do you measure species evenness
measure the number and abundance of each species
What does a diversity index show?
is used to calculate a quantitative score of diversity that takes into account both richness and evenness
The more genetically diverse a population…
the more different combinations of alleles there will be in the population
If genetically diverse…
there’s more heterozygotes
Why is variation important?
if the environment changes due to illness or surroundings etc then it makes the population more resistant to changes in their environment
Why are smaller populations more vulnerable?
because they are more likely to lose alleles from their gene pool and become less genetically diverse
Reasons for conservation (zoos)
- all species have a right to exist
- preservation of biodiversity for the benefit and enjoyment of future generations
- for aesthetic reasons
- for economic reasons
- for practical reasons
- for ecological reasons to avoid destabilisation
In-Situ conservation approach
- is preferable to protect and manage species habitats so those at risk can recover in their natural environment
- managing habitats may include enhancing the available shelter and sources of food, or by introducing measures to reduce predation
Ex-situ conservation
- in some cases organisms may need to be removed from their original habitat
- generally more expensive but may be the only option
What is the role of zoos?
- education
- centres for scientific research
- centres for captive breeding
- enable reintroduction of endangered species back to the wild
Mechanisms of conservation
- breeding endangered species in captivity
- reduce habitat loss (restrict industrial and urban development)
- reintroducing captive bred species to the wild
- introducing laws to protect wildlife and the environment
- establishing national parks, nature reserves and other conservation areas
- educating people about the need for conservation
Genetic Drift
some alleles may purely by chance not get passed on to offspring, leading to a reduction in genetic diversity
Inbreeding depression
a reduction in genetic diversity can lead to an increase in recessive alleles - more likely to inherit homozygous recessive, as a result are less likely to survive and reproduce
How can we help make species reintroduction to the wild more successful?
- keep them in their native habitat
- teach them skills e.g. food, defend themselves, shelter
- captive breeding successful
How can we reduce inbreeding and maintain genetic diversity within captive breeding?
- partner selection/ IVF
- keep a stud book/ records
- DNA profiling
- don’t allow the same individual to continually breed together
Germination
when the root and shoot appear from the seed (not the same as growing)
Why are seeds vital for plant survival? They’re adapted to ensure they…
- protect the embryo
- aid dispersal
- store nutrients for the new plant to start growing (starch for energy)
Seeds in a dormant state…
no chemical reactions take place
What is a dormant seed?
a seed that is unable to germinate at that time - it’s a mechanism to delay germination until conditions are suitable
Viability
the ability of a seed to brake dormancy or germinate
Unviable seeds…
won’t ever germinate even in suitable conditions
What are advantages of storing seeds in a seed bank?
- it’s cheap
- few ethical issues
- don’t take up much space
What 2 conditions are important for storing seeds correctly? Why?
-20°C, low humidity (cold and dry)
this slows the metabolism so it reduces the rate of enzyme controlled reactions
How can we conserve plants?
either in-situ - in their natural habitat or ex-situ - in seed banks or botanical gardens
How can we maintain genetic diversity at a seed bank?
by collecting seeds from different places and different plants
What happens to all seeds over time?
they lose their viability because the cells may die and it may become less metabolically active (if they remain viable they’ll wait for the right/advantageous conditions before germinating
