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35 Cards in this Set

  • Front
  • Back
What is species richness?
The number of different species within an area of known size at a particular time. A species is a group of organisms with so many features in common that they can mate and produce sexually viable offspring.
What is genetic diversity?
The genetic variation within a species.
How would you measure species richness?
To measure the species diversity, random sampling can be carried out. A number of quadrats (often 10) of know size are randomly placed in an area. All the species found in each quadrat are recorded and used to estimate the total species richness.
What is a gene pool?
The total number of genes a species has.
Define endemism?
Endemism describes the situation where a species is found in only one particular area. The ring-tailed lemur is restricted to the island of Madagascar and so is considered to be endemic to Madagascar.
What is molecular phylogeny?
Molecular phylogeny compares the structure of a particular molecule from different organisms to discover their degree of evolutionary relatedness. The more similar the structure of the molecule, the more closely related the organisms are to each other. This is because changes in molecule structure generally occur only slowly as they are caused by mutations.
What three domains have been identified based on molecular phylogeny?
1. Bacteria
2. Archaea
3. Eukaryota
What is a niche?
A niche is the way a species exploits it environment.
What happens if two of more species are present in the same niche?
There will be competition and one species will out compete the other so that the better adapted will survive.
What are the main types of adaptations?
-Anatomical
-Behavioural
-Physiological
What is an anatomical adaptation?
A physical/ structural adaptation- It may be external or internal.
What is a behavioural adaptation?
A change in the behaviour of an organism to increase its survival chances.
What is a physiological adaptation?
These tend to be changes in the internal biochemical functioning of the organism in response to an altered environmental stimulus.
What is natural selection?
The survival of individuals in a population because they have alleles that improve their chances of survival and reproduction.
What is evolution?
The change in the frequency of certain alleles in a gene pool over time due to natural selection.
What is the evolutionary sequence?
-A population of organisms shows genetic diversity due to having a variety of alleles (caused by mutations)
-Environmental conditions change.
-Natural selection removes some individuals with alleles that are not as advantageous.
-The remaining individuals grow and reproduce, passing on the advantageous alleles.
-Over many generations the frequency of these alleles increases.
How do we conserve endangered species?
-Zoos
-Seed banks
What are the roles of zoos in conserving endangered animals?
1. Education
2. Scientific Research
3. Captive-breeding programs
4. Reintroduction programmes
How do zoos educate people?
They inform all age groups about illegal trade in certain animal products such as ivory, how biodiversity needs to be maintained and about captive breeding programmes.
How do zoos carry out scientific research?
Zoos and universities work together to research and find out more about the control of diseases that are reducing populations/ behavioural studies to further appreciate the needs of animals in captivity/ development of techniques to further improve breeding success.
What is the main purpose of captive-breeding programmes?
Designed to encourage endangered species to breed to that their numbers increase, reducing risk of extinction. Subsequently some individuals can be released into the wild or protected areas such as national parks, to maintain or re-establish wild breeding populations. Thus the genetic diversity of a species is maintained.
What is the main purpose of reintroduction programmes?
These programmes endeavour to release captive- bred individuals back into the wild so that natural breeding populations can be maintained or re-established.
Con of captive breeding programmes?
Some zoos have a small number of individuals, inbreeding is likely to occur.
Why is inbreeding a bad thing?
It results in reduced genetic diversity and, therefore, a reduced chance of adapting to environmental change.
There is also an increased risk of a genetic condition becoming more common in the breeding population.
What techniques are used to reduce inbreeding and maintain genetic diversity?
-Do not allow the organisms to repeatedly breed with the same partner, possibly by isolating partners.
-Select partner, possibly by adding a potential partner to a cage, IVF or inter-zoo swapping.
-Keep a record/database of individuals in captivity and their breeding history, e.g. stud books, so that choice of partner is controlled.
What are seed banks?
Seeds from a variety of endangered plants can be stored in a dormant state in seed banks. however not all seeds can be stored this way.
Why are seeds stored instead of living plants?
-Less space is required so more species can be held in the available space.
-Most plants produce large numbers of seeds so collecting small samples is unlikely to damage the wild population.
-Easier to store because they are dormant.
-More cost effective.
How do seed banks conserve a rare plant species?
-Seeds are collected from a number of individual plants.
-Seeds X-rayed to check for fully formed embryos.
-Seeds dried to remove water.
-Seeds stored in the cold e.g. -20 degrees Celsius
-Some seeds periodically germinated to check viability.
What happens if less than 75% germinate?
Those that did germinate are allowed to grow into mature plants that produce their own seeds which are then stored.
What happens if more than 75% germinate?
The remaining seeds are retained in cold storage and will be checked again for viability.
What common feature do plant and animal cells have?
-A nucleus surrounded by a double membrane or envelope.
-Organelles in the cytoplasm surrounded by one membrane or two membranes.
What are the structural features of a chloroplast?
-Double membrane
-Many internal membranes (thylakoid), some are arranged as stacks called grana (granum)
-Chloroplast found on the thylakoid membranes.
-Fluid filled interior called the stroma.
-A loop of DNA is found in the stroma.
-starch grains may also be present in the stroma.
What are the structural features of an amyloplast?
-Double membrane present.
-Contains one type of starch called amylopectin.
-Amylopectin sometimes shows concentric rings.
What are the structural features of vacuoles?
-Surrounded by a single membrane called tonoplast.
-Contains cell sap.
What are the structural features of a cell wall?
.