SECTION A - Multiple-choice questions

GTAC Biology Revision Series

Evidence for evolution

SECTION A - Multiple-choice questions

Consider the footprints of Australopithecus afarensis dated to 3.7 million years ago. The image

relates to questions 1 and 2.

Question 1 The fossil is best described as a:

A Trace fossil

B Transition fossil

C Cast

D Coprolite

Question 2 Which technique would most accurately date the mineral layer in which the fossil occurs?

A Radiometric dating using 14C

B Radiometric dating using 39K

C Comparative dating with sediments above the layer

D Correlative dating with footprints at remote sites


Consider the rock layers from two distant sites, X and Y. The image relates to questions 3 and 4.

Question 3 It would be reasonable to conclude that the following layers are the same age:

A Layers 1 and 5

B Layers 1 and 6

C Layers 2 and 6

D Layers 3 and 4

Question 4 Which fossil makes a suitable index fossil?

A

B

C

D


The following image relates to question 5.

Question 5 The animal in the picture above can be classified as a hominoid because it has:

A Hair

B No tail

C Forward-facing eyes

D A relatively enlarged cranium

Question 6 An organism has opposable digits on the hands and feet, eyes adapted for stereoscopic vision, a flexible

spine, and a tail. It would be reasonable to conclude the organism is a:

A Mammal

B Primate

C Hominoid

D Hominin


SECTION B – Written responses

Question 1 (7 marks) Darwinius masillae (nicknamed ‘Ida’, Fig. 1) is a fossil primate found in the Messel sediments in

Germany. Radiometric dating of the deposits in which D. masillae was buried gives an estimated age of

47 million years old. Messel is a lake deposit that formed in the shallow crater of a volcano. It is

believed that toxic gas emitted from the lake killed local wildlife. Some of the poisoned wildlife fell into

the lake and became fossilised over time.

Fig. 1. The fossil of Darwinius masillae from Messel, Germany.

Source: Franzen et al. (2009). PLoS ONE 4(5): e5723. doi:10.1371/journal.pone.0005723 (CCAS 2.5)

a. Describe two conditions at the time of the organism’s death that would have favoured fossilisation of

D. masillae. (2 marks)

b. Dinosaurs became extinct approximately 65 million years ago. Deduce whether deposits containing

dinosaur fossils would be above or below or in the same deposits as those containing D. masillae.

Explain why. (2 marks)


c. What diagnostic feature proves D. massae was a primate? (1 mark)

d. Determine if D. massae was a hominoid and justify your decision. (2 marks)

Suggested responses begin on the next page.


Evidence for evolution written responses: Suggested responses

In general, note the command and interrogative terms: describe, deduce, explain, what, determine,

justify.

1a. Describe two conditions at the time of the organism’s death that would have

favoured fossilisation of D. masillae. (2 marks) Response you wrote:

Suggested response:

Any two of:

- Lack of oxygen, suppressing the action of scavengers and decomposers (e.g. fungi)

- Lack of scavengers, limiting interference with deceased remains

- Lack of decomposers, limiting the decay of deceased remains

- Alkaline conditions that limit the degradation of deceased remains

1b. Dinosaurs became extinct approximately 65 million years ago. Deduce

whether deposits containing dinosaur fossils would be above or below or in the

same deposits as those containing D. masillae. Explain why. (2 marks) Response you wrote:

Suggested answer:

Below – the deposits in which D. masillae occurs are younger (47 million years old); older deposits are

gradually buried by younger ones over geological time.

Tips for answering this question: The command term is “describe” so the examiner is seeking detail

about two of the conditions that lead to fossilisation. For full marks, nominate both the condition

and how it contributes to preservation and fossilisation. Take care to only include detail that is

relevant to the question. For example, the response must relate to conditions at the time of the

organism’s death and not to conditions related to burial for extended periods of geological time.


1c. What diagnostic feature proves D. massae was a primate? (1 mark)

Response you wrote:

Suggested answer:

D. massae has opposable digits.

1d. Determine if D. massae was a hominoid and justify your decision. (2 marks) Response you wrote:

Suggested answer:

D. massae was not a hominoid; D. massae has a tail, whereas hominoids do not.

Tips for answering this question: The command term “deduce” instructs the student to reach a

logical conclusion using the information provided. The command term “explain” (why) instructs the

student to provide a detailed account of the reason for their decision. For a detailed account, link

the evidence of the fossils’ ages (65 million years versus 47 million years) with processes that

rationalise relative dating. For full marks, give both the deduction and the explanation.

Tips for answering this question: The interrogative term “what…?” is implicitly a command term, to

“state what”. It requires a brief answer without explanation. Note that the most obvious opposable

digit displayed by the fossil, D. massae is the big toe (hallux) of the foot. Take care to provide the

most relevant answer. Characteristics such as forward-facing eyes and a flexible spine are typical of

primates but they are not the diagnostic feature.

Tips for answering this question: The command term “determine” requires the student to produce

only one possible answer. The command term “justify” invites the student to provide evidence or a

reason in support of their answer. In order to classify the fossil as a hominoid the student must

assess the fossil against key knowledge that hominoids (apes) lack a tail. The fossil has a

conspicuous tail, enabling the student to make the determination (not a hominoid) and justify with

the evidence for full marks.

Documents

SECTION A - Multiple-choice questions