Topic 5 SNAB, On The Wild Side

Topic 5: On the Wild Side




Photosynthesis:
Suggest reasons why 95% of the light hitting the surface of a leaf is not used by the
chloroplasts. (2)*Reflection; *incorrect wavelength/colour/ frequency; *light doesn't hit the
chloroplast/ chlorophyll, it is transmitted; *light being in excess e.g. at max. photosynthesis so no
more…

Topic 5: On the Wild Side




Suggest why the development of plants depends on the rate of carbon fixation. (3)
*Carbon fixation produces {GP / eq}, this *product is converted to glucose/ starch/ eq. *The faster
the C- Fixation the faster the glucose/ starch production, as the *rate of growth…

Topic 5: On the Wild Side




there are *great fluctuations in most climate change data suggest that there is no real trend (as
scattered) and thus *poor representation of raw data. *A scatter of results may show poor
reliability.

In addition the method of* estimating temperature from growth rings of…

Topic 5: On the Wild Side




maximum to be able to complete development/ above the lethal temperature limit. *Species may
also move north/ to cooler regions or they may have a *change to their food source/predators/
competition.

Suggest why the lower and upper lethal temperatures limit the range of latitudes…

Topic 5: On the Wild Side




Suggest why an increase in temperature may cause an increase in NPP. (2) *The
rate of (bio)chemical/metabolic/photosynthetic reactions increases due to an *increase in
movement/kinetic energy of enzyme/substrate/molecules; *thus increasing the reaction rate
because of more enzyme substrate interaction/ collisions.

What is the unit…

Topic 5: On the Wild Side




Why is a climax community stable? (4)
*A climax community is where (both) animals and plants are present/has many species/has high
biodiversity; *there will be interaction between these species but they *will have reached a
balanced equilibrium of species. *There may be a (co)dominant…

Topic 5: On the Wild Side




advantageous features/mutations would allow the plants to *survive and reproduce, passing on new
genes and creating *differences between gene pools.

Suggest how ecological isolation contributes to speciation. (2)
*There may be different conditions /environments in each region, i.e. a temperature difference, so
*there will…

Topic 5: On the Wild Side




Describe the chemical nature of cellulose. (3)
Cellulose is a *polysaccharide with an *unbranched/ straight chain. The cellulose is made up of *B
glucose joined by *1-4 glycosidic bonds between the glucose molecules. Between each chain there
are *intermolecular hydrogen bonds to hold the…

Topic 5: On the Wild Side




How does mRNA form during transcription in the nucleus? (3)
First the *DNA strands unzip, *one side of the DNA strand is the template strand that is used to from
a mRNA strand *from free nucleotides. The nucleotides join by *complementary base pairing, *joined…

Topic 5: On the Wild Side




Conservation

Explain how the work of zoos could be important to the survival of endangered species. (2)
Zoos may run *captive-breeding programmes *which conserve alleles/genes/ the gene pool of a
species and may run *reintroduction programmes/ re-introduce species into suitable habitats in the
environment.…