Variety of life T4 Flashcards
What is meant by niche?
Niche is the match of a species to a specific environmental condition/ecosystem.
Suggest how natural selection could have given rise to the adaptations shown by the waxy
leaf frog.
(5)
- Selection pressure/change in environment.
- Competition/predation.
- Mutation in frog.
- Advantageous allele i.e. waxy secretions.
- Individuals with advantageous allele more likely to survive and breed.
- Advantageous allele/mutation passed on to future generations.
- Increase frequency of advantageous allele in population.
State what is meant by the term endemic.
-Species found in only one geographical location.
Describe what is meant by biodiversity.
2
-The variety of species in an ecosystem/community/habitat.
The variety of alleles in a gene pool/population/species.
Explain how the biodiversity of lemurs in two different parts of Madagascar could be
compared.
(3)
- Record number of species of lemur and the number of individuals of each species.
- Calculate diversity index for both locations.
- Higher the index, the greater the diversity.
- DNA profiling/gel electrophoresis/molecular phylogeny.
In the 1970s, a theory for a new system of taxonomy was proposed by a scientist called Woese.
Describe the process by which the scientific community critically evaluates new theories.
(3)
- Communicating theory to scientific community.
- Peer review.
- Checking evidence to ensure validity.
Although chiffchaffs and willow warblers are often found at the same time in the same
woodlands, they do not interbreed.
(i) Suggest why successful interbreeding between chiffchaffs and willow warblers would make
some scientists doubt their classification as separate species.
(3)
- Succesful interbreeding produces offspring.
- Same species produce fertile offspring.
- Offspring of different species would be infertile due to dif. number of chromosomes/genetic incompatibility.
Suggest reasons why two species may not interbreed.
3
- Reproductive isolation.
- Different breeding times.
- Physical incompatibility i.e. genitals.
Records show that very little change in the appearance of chiffchaffs and willow warblers has
occurred during the last two hundred years.
Suggest why the rate of change in the appearance of these two species is relatively slow.
(3)
- Two species share the same habitat.
- Two species experience same environmental conditions.
- Therefore the same selection pressures.
- They’re both well adapted to their environment.
- No mutations have occurred that have improved their phenotypes/survival.
- So no changes in allele frequency/gene pool stable.
- There has been little change in environment over the years.
Epilobium latifolium is a plant that occupies a niche in an area once covered by this glacier.
It is a short flowering plant that grows in clumps.
Explain what is meant by the term niche, using the plant Epilobium latifolium as an example.
(3)
- The interaction of an organism with it’s environment/ecosystem.
- Epilobium latifolium is a producer (make their own food, opposite of consumer).
- Epilobium latifolium provides food,energy for other organisms/primary consumers/decomposers.
- Epilobium latifolium holds soil together. Improves soil, increases nutrients.
- Epilobium latifolium provides shelter for other organisms/micro habitat. Insects.
Describe how to carry out a study of the distribution of Epilobium latifolium from the front
edge of a glacier.
(4)
- Using a transect from the front edge of glacier.
- Systematic sampling.
- Use more than one transect.
- Estimate abundance/ number of plants.
- Put data into table/graph/tally chart.
Suggest one abiotic (non-living part of an ecosystem) factor that might affect the abundance of Epilobium latifolium and describe how this factor could be measured.
(3)
- Light, soil ph, water content, mineral content, temp., wind.
- Measure light using probe. Dry out soil samples etc.
- Reading of soil taken at soil around roots etc.
- Take several readings for an average.
