Download D.1 and D.2 Practice Test KEY

D.1 d.2 Practice Test ANSWER KEY
Option D — Evolution
D1. (a)
as latitude increases so does wing size / direct relationship / positive correlation [1]
Do not accept directly proportional as line does not pass through origin.
(b) (i)
1. at higher latitudes/above 45º European species have larger wings than American
species/largest wing sizes seen in European flies;
2. European flies show more variation than American flies (steeper curve);
3. at lower latitudes/below 45º North American flies have larger wings than European
species;
4. South American flies have smaller wing size than European/ N. American flies;
[2 max]
(ii)
1. American species show less variation because they have had less time to diverge /
evolve;
2. size of American flies closer to that of flies recently introduced/founder
effect/European founder population from low latitudes;
3. American flies exposed to different selective pressures;
[1 max]
(c)
1. These isolated populations will diverge (genetically) / separation of gene pools;
2. These isolated populations may become a new species / allopatric speciation;
3. The wing size will follow same trend as in Europe as population spreads to higher
latitudes;
4. The wing size will follow same trend as in Europe because larger size favoured by
higher latitudes;
5. The wing size may stay small due to smaller gene pool;
[2 max]
D2. (a)
1. One process need for the spontaneous origin of life is the non-living synthesis of
simple organic molecules/amino acids from inorganic molecules;
2. Another process needed for the spontaneous formation of life is the assembly of these
simple organic molecules into polymers/polypeptides;
3. Another process needed for the spontaneous formation of life the origin of selfreplicating molecules that made inheritance possible;
4. Another process needed for the spontaneous formation of life is the packaging of
these monomer and polymer organic molecules into membranes with an internal
chemistry different from their surroundings;
[2 max]
(b)
1. RNA is self-replicating and can perform catalytic activities;
2. short sequences of RNA have been able to duplicate/copy other RNA molecules
accurately;
3. RNA enzyme/ribozyme are able to synthesize other molecules;
4. 3-dimensional structure of ribosome catalytic sites (for peptide formation) are
composed of RNA;
5. RNA is able to store information in sequence of (4) nucleotides (similar to DNA);
[2 max]
D.2.1 More questions
D2. (a)
1. limb bone pattern of mammals shows the same basic arrangement;
2. The similarity in Limb bones of mammals suggests that the limbs are derived
from common ancestor/homologous structures;
3. Theses common ancestral bone pattern of the front limbs are adapted to different
environment conditions and thus form and function were subject to different
selective pressures;
4. suitable example; (eg wing of bat adapted for flight and limbs of mole for
digging)
[2 max]
(b)
1. both forms of speciation result in the formation of new species by the splitting of
an existing one;
2. in both forms of speciation, interbreeding by separated groups is prevented;
3. sympatric exist in same geographical area while allopatric exist in geographical
isolation;
4. sympatric is due to reproductive/behavioural isolation while allopatric might
not;
5. suitable example of mechanism or organisms for each (eg: allopatric: separation
of formerly linked waterways into isolated ponds in which separate fish species
evolve and sympatric: temporal isolation / maggots feeding on apples do not
mate with maggots feeding on hawthorn / different calls isolating species of bats)
D.3 b.
1. homologous structures evolved from a common ancestor while analogous
structures did not;
2. example of homologous and example of analogous; (examples of both are
needed)
(c)
a. transient polymorphism Is when there are two alleles in a gene pool/ a species
is polymorphic;
b. In transient polymorphism one allele gradually replacing another;
c. Transient polymorphism is due to strong selection pressure for one allele over the
other;
d. example; (e.g. melanic moths/industrial melanism )
3 max
(d)
1. Punctuated equilibrium are periods of stability/little evolution/stasis, followed by periods of
sudden
major change/lot of evolution/rapid speciation;
2. During these periods of stability organisms become well-adapted to environment;
3. During the stable periods natural selection acts to maintain characteristics;
4. This equilibrium is punctuated by rapid environmental change;
5. An environmental change, such as volcanic eruption / meteor impact / change in sea level;
6. After a large environmental change there can be directional selection which leads to rapid
evolution; Directional selection occurs if a change in the environment creates a selective
pressure that strongly selects for a particular phenotype, then this directional selection will
lead to rapid evolution;
7.
4 max
2. [7]
e) A gene pool is all the genes in an (interbreeding) population
1