Download New evolution test 2 MS

1.
(a)
Archaeopteryx
(b)
Velociraptor no flight and Columba flight;
flapping in both;
three fingers in both;
half-moon-shaped wrist bone in both (allows flapping);
bones fuse / less in Columba and separate / more in Velociraptor;
digit II is the longest in both;
both have hollow bones;
[1 max] for descriptions of each with no comparison.
(c)
comparative anatomy / homologous anatomical structures /
similar basic structural features but structure adapted to function /
similar to pentadactyl limb example; paleontological / fossil evidence;
1
3 max
2
[6]
2.
(a)
70 – 74
(b)
more spread of pair differences in African than non-African;
greater maximum of frequency of pair differences in non-Africans than Africans;
non-Africans maximum frequency is at 30–34 pair differences and Africans at 70–74;
neither population had zero pair differences;
3 max
(c)
African;
more pair differences show a longer genetic history;
1
2
[6]
3.
(a)
(b)
parents produce more offspring than survive;
there is competition among members of a species for survival /
struggle for existence;
species show variation;
certain variations will give a selective advantage / survival of fittest;
depending on the environment;
these variations will be passed on to the next generation;
leading to change in allele frequency;
4 max
change of beak shape in Galapagos finches;
resistance to pesticides / antibiotics;
bird predation on moths; (allow, though some evidence refutes this)
heavy metal tolerance in plants;
melanism in ladybirds (ladybugs);
2 max
1
(c)
fossils;
prints / moulds;
preserved in amber / tar / peat / petrification;
frozen in ice;
2 max
[8]
4.
(a)
lemurs / lorises
(b)
Old World monkeys closer to Great apes / New World monkeys
closer to lemurs / lorises;
overlap / coincide at some point;
wider range in New World monkey cerebrotypes than in Old
World monkeys;
2 max
coincides with DNA tree / different to morphology;
because of exact match;
shows that Pan / chimp and Homo / human are close;
gorilla less close;
orangutan / Pongo further away;
2 max
(c)
(d)
1
carbon dating / 14C dating / 40K dating;
measure the amount of isotope relative to original amount / less of the
original isotope present the older the fossil / age can be calculated by
knowing the half life of the isotope;
2
[7]
5.
(a)
cytochrome C
1
(b)
hemoglobin β-chain : fibrinopeptides = 2.8 ( 0.2)% : 12.3 ( 0.2)% / fibrinopeptides have (about) four times more substitutions / (about) 10% more in
fibrinopeptides
1
(c)
sheep because fewer differences in base substitutions
1
(d)
mutations occur randomly;
amino acid sequences change;
differences accumulate gradually over a long time;
the differences accumulate at a (roughly) constant rate;
can be used as an evolutionary clock;
2 max
[5]
6.
(a)
(b)
Award [1] for two of the following.
petrification / fossilization / preservation in amber / ice / peat /
mummified (dehydration)
1
mutations occur over time in a genome / DNA / gene;
mutations occur at a relatively constant rate;
differences in DNA can lead to differences in amino acid sequences;
2
eg in humans the β-chain of hemoglobin / cytochrome c / other
example / is more similar to primates than other mammals;
more precision seen in genes with reliable rate of change;
number of substitutions in gene / mtDNA / Y chromosome can
be graphed against branch points / changes in fossil / archaeological
record;
Award [2 max] if no example is given.
(c)
organisms with common ancestry found in areas geographically
separated have different adaptations / divergent evolution;
eg Darwin’s finches in the Galapagos Islands / New World monkeys
in America and Old World monkeys in Africa / marsupials in Australia;
Wallace’s Line is an example of geographical distribution of
organisms due to evolution;
similar adaptations of unrelated organisms in similar habitats /
convergent evolution;
eg streamlined shape of dolphins and fish;
3 max
2 max
[6]
7.
(a)
Carettochelys
(b)
both have a common ancestor / common ancestor in the
cretaceous / ancestral line evolved in the Jurassic;
Chelonia has 3 divergence points from ancestor whereas
Graptemys has five;
Graptemys has more recently diverged than Chelonia / Graptemys
evolved later than Chelonia;
2 max
Graptemys and Trachemys;
(as) these separated most recently;
Graptemys and Trachemy are closely related to Emys / Mauremys and
Heosemys are also closely related but diverged further back in time;
lack of fossil evidence to show that other pairs could be more
closely related;
reliability of molecular dates could be questioned / reliability
of fossil dates could be questioned;
3 max
(c)
1
[6]
3