How many SCSA Human Biology questions cover Evidence for evolution?

AusGrader has 70 SCSA Human Biology questions on Evidence for evolution, all with instant AI grading and detailed marking feedback.

SCSA Human Biology Evidence for evolution

5 sample questions with marking guides and sample answers · Avg. score: 80.8%

Q26

2024

SCSA

1 mark

Q26

1 mark

The following is a list of statements associated with fossil formation.

I. Decomposition is slowed by an anaerobic environment
II. Specimens need to be exposed to decomposers
III. Hard body parts become fossils through mineralisation
IV. Specimens need to be buried rapidly
V. Specimens need to be disturbed for fossilisation to occur

Which of the following describes correctly the conditions needed for fossilisation to occur?

I, III and IV only

I, II and IV only

II, III, IV and V only

II, IV and V only

Q25

2022

SCSA

1 mark

Q25

1 mark

A scientist used the potassium-argon dating method to determine the age of a sample. This type of dating involves comparing the amount of

Argon-40 and Potassium-40 to the remaining Calcium-40.

Potassium-41 remaining in the sample to the amount of Argon-41.

Argon-40 in the sample to the remaining amount of Potassium-40.

Argon-40 and Calcium-40 to the remaining Potassium-41.

Q41

2021

SCSA

20 marks

Q41

It is estimated that millions of hominins pre-dating the modern Homo sapiens have populated the Earth and yet only 6000 individuals are represented in the hominin fossil record.

Q41a

10 marks

Explain why there are so few fossils in the fossil record.

Generally only hard or solid parts, such as bones and teeth, are fossilised. Organisms need to ‘die’ in an area suitable to fossilisation, and the sediments or soils need to be of the right conditions. Organisms need to be protected from decay from microorganisms, and the remains need to be undisturbed by scavengers. The remains need to be quickly covered by sediments for rapid burial, and the sediments need to be undisturbed by geological processes. Many fossils are buried too deep to be found. Many fossils are destroyed by geological processes or human activity, and many fossils are not recognised as being so. Finally, many fossils once exposed are eroded or weathered.

Marking Criteria

Descriptor	Marks
1 mark for each correct point (any 10 of): Generally only hard/solid parts e.g. bones/teeth are fossilised; Organisms need to ‘die’ in area suitable to fossilisation; The sediments/soils needs to be of the right conditions/alkaline/low oxygen levels; Organisms need to be protected from decay from microorganisms; The body/remains need to be undisturbed by scavengers; The body/remains need to be quickly covered by sediments/rapid burial; The soil/sediments need to be undisturbed by geological processes; Many fossils are buried too deep to be found/not exposed to the surface; Many fossils are destroyed by geological processes/human activity; Many fossils are not recognised as being so/people don’t recognise them; Many fossils once exposed are eroded/weathered	10

Descriptor

Marks

1 mark for each correct point (any 10 of): Generally only hard/solid parts e.g. bones/teeth are fossilised; Organisms need to ‘die’ in area suitable to fossilisation; The sediments/soils needs to be of the right conditions/alkaline/low oxygen levels; Organisms need to be protected from decay from microorganisms; The body/remains need to be undisturbed by scavengers; The body/remains need to be quickly covered by sediments/rapid burial; The soil/sediments need to be undisturbed by geological processes; Many fossils are buried too deep to be found/not exposed to the surface; Many fossils are destroyed by geological processes/human activity; Many fossils are not recognised as being so/people don’t recognise them; Many fossils once exposed are eroded/weathered

Q41b

10 marks

Explain, using examples, how the comparative studies of anatomy can be used for the construction of phylogenetic trees.

Any 2 of comparative embryology, homologous structures, or vestigial organs

For comparative embryology:
We compare anatomical structure during embryo development. Organisms share similar anatomical structures during early development, which indicates shared common ancestry. The more similar the structures are for longer in the embryonic stage, the more closely placed together they are on phylogenetic trees. An example is gill slits and a tail found in vertebrate embryos.

For homologous structures:
We compare anatomical structure from different species. Structures show a high degree of structural similarity but perform different functions, which indicates shared common ancestry. The more similar the structures are, the more closely placed together they are on phylogenetic trees. An example is the bone structure in the vertebrate limbs.

For vestigial organs:
These are homologous structures that have a benefit in some species, but are present but not functional in other species. This indicates shared common ancestry. More shared features mean they are more closely placed together on phylogenetic trees. An example is wisdom teeth in humans.

Marking Criteria

Example 1

Descriptor	Marks
1 mark for each correct point for one chosen example: Comparative embryology (Compares anatomical structure during embryo development/stages of embryo development from different species; States that organisms share similar anatomical structures during early development; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the basic structure; Explains that the more similar the structures are for longer in the embryonic stage = more closely placed together on phylogenetic trees; Provides an example); OR Homologous structures (Compares anatomical structure from different species; States that structures show a high degree of structural similarity but perform different functions; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the basic structure; Explains that the more similar the structures are = more closely placed together on phylogenetic trees; Provides an example); OR Vestigial organs (Describes homologous structures that have a benefit/normal function in some species; States that they are present but not functional in other species; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the structure; Explains that more shared features = more closely placed together on phylogenetic trees; Provides an example).	5

Descriptor

Marks

1 mark for each correct point for one chosen example: Comparative embryology (Compares anatomical structure during embryo development/stages of embryo development from different species; States that organisms share similar anatomical structures during early development; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the basic structure; Explains that the more similar the structures are for longer in the embryonic stage = more closely placed together on phylogenetic trees; Provides an example); OR Homologous structures (Compares anatomical structure from different species; States that structures show a high degree of structural similarity but perform different functions; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the basic structure; Explains that the more similar the structures are = more closely placed together on phylogenetic trees; Provides an example); OR Vestigial organs (Describes homologous structures that have a benefit/normal function in some species; States that they are present but not functional in other species; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the structure; Explains that more shared features = more closely placed together on phylogenetic trees; Provides an example).

Example 2

Descriptor	Marks
1 mark for each correct point for a second chosen example: Comparative embryology (Compares anatomical structure during embryo development/stages of embryo development from different species; States that organisms share similar anatomical structures during early development; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the basic structure; Explains that the more similar the structures are for longer in the embryonic stage = more closely placed together on phylogenetic trees; Provides an example); OR Homologous structures (Compares anatomical structure from different species; States that structures show a high degree of structural similarity but perform different functions; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the basic structure; Explains that the more similar the structures are = more closely placed together on phylogenetic trees; Provides an example); OR Vestigial organs (Describes homologous structures that have a benefit/normal function in some species; States that they are present but not functional in other species; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the structure; Explains that more shared features = more closely placed together on phylogenetic trees; Provides an example).	5

Descriptor

Marks

1 mark for each correct point for a second chosen example: Comparative embryology (Compares anatomical structure during embryo development/stages of embryo development from different species; States that organisms share similar anatomical structures during early development; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the basic structure; Explains that the more similar the structures are for longer in the embryonic stage = more closely placed together on phylogenetic trees; Provides an example); OR Homologous structures (Compares anatomical structure from different species; States that structures show a high degree of structural similarity but perform different functions; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the basic structure; Explains that the more similar the structures are = more closely placed together on phylogenetic trees; Provides an example); OR Vestigial organs (Describes homologous structures that have a benefit/normal function in some species; States that they are present but not functional in other species; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the structure; Explains that more shared features = more closely placed together on phylogenetic trees; Provides an example).

Q39

2024

SCSA

20 marks

Q39

Researchers in Ethiopia found a relatively complete hominin skeleton. Looking at the skeleton it was not clear which form of locomotion the hominin had used. The specimen showed features that could be linked with both bipedalism and brachiation.

Q39a

10 marks

Identify six anatomical features of the skeleton that could have been present in the shoulders, arms, and hands to support brachiation as a means of locomotion, and explain how the shoulders, arms and hands allow for brachiation.

Features of brachiation include:

Shoulders with a reduced clavicle, high shoulder blades, and a backwards facing socket of the scapula.
Longer arms and a flexible elbow joint.
The hands have long, curved fingers, short thumbs, and a robust but flexible wrist joint.

These features are adapted for swinging in trees. The hands are adapted to grasp branches. These adaptations provide strength to support the weight of the hominin in trees and create an energy efficient pattern of movement.

Marking Criteria

Descriptor	Marks
1 mark for each correct point (any 6 of, with at least one from each category): Shoulders: short/reduced clavicle, high shoulder blades, mobile shoulder joint/backwards facing socket of scapula Arms: longer arms/smaller arm to leg ratio/long, robust humerus/long, slender radius and ulna, flexible elbow joint Hands: long, curved fingers, short thumbs, robust but flexible wrist joint	6
Explains that these features are adapted for swinging in trees, circular arm movements, or flexibility of arms to rotate	1
Explains that hands are adapted to grasp branches or hang from branches	1
States that these adaptations provide strength to support the weight of the hominin in trees	1
Concludes that this creates an energy efficient pattern of movement	1

Q39b

4 marks

Identify two anatomical features of the skeleton that could have been present in the pelvis to support bipedalism as a means of locomotion, and outline how these features would allow for bipedalism.

The pelvis: short, broad, and bowl-shaped pelvis

These features ensure support of body organs and help propel the body forward during locomotion.

Marking Criteria

Descriptor	Marks
1 mark for each correct point (any 2 of): wide pelvis/short and broad pelvis bowl-shaped pelvis; forward facing acetabulum robust sacroiliac joint/sacrum to ilium joint reduced iliac crest	2
1 mark for each correct point (any 2 of): ensures weight-bearing/support of body organs helps propel the body forward during locomotion creates energy efficient pattern of movement provides a large area for muscle attachment creates balance/stability creates the striding gait motion	2

Q39c

6 marks

Researchers were unable to provide an actual date for the fossil skeleton. They were however, able to use stratigraphy to date the fossil.

Name and describe two ways in which stratigraphy is employed to date a fossil.

The principle of superposition states that the youngest rocks are at the top, while the oldest are underneath, meaning fossils higher in the layers are younger.

The correlation of rock strata involves rock strata from one location being matched with another location, so fossils in matching rock strata are the same age.

Marking Criteria

Descriptor	Marks
Identifies the principle of superposition	1
Explains that the youngest rocks are at the top, while the oldest are underneath	1
States that fossils higher in the layers are younger	1
Identifies the correlation of rock strata	1
Explains that rock strata from one location are matched with another location	1
States that fossils in matching rock strata are the same age, or mentions matching index fossils to determine age	1

Q40

2021

SCSA

20 marks

Q40

Excavations of the sediments at an Aboriginal rock shelter in Juukan Gorge found flaked stone artefacts and a 4000 year-old belt made of plaited hair. A survey of the sediments provided a pollen record charting thousands of years of environmental changes.

Q40a

12 marks

Name and describe two techniques that could be used to date the stone artefacts and one technique that could be used to date the hair belt.

There are relative and absolute dating methods.

For stone artefacts (any 2 of the following):

Stratigraphy studies the rock strata, and matches similar strata to other strata already dated.
Principle of superposition assumes lower rock layers are older, and as such deepter artefacts are older.
Index fossils . Fossils widely found but only present for a limited time on Earth. Match index fossils from various locations with known dates.

For the hair belt:
Use C14 dating, which is based on the decay of C14 to nitrogen. The amount of C14 is fixed at death, with a half-life of 5730 years. The ratio of C14 to C12 determines the age.

Marking Criteria

General

Descriptor	Marks
Indicates an understanding there are relative and absolute dating methods	1

Stone Artefacts

Descriptor	Marks
3 marks for each technique named and described (any 2 of): stratigraphy (study the rock strata/layers, match similar strata to other strata already dated/artefacts in the same strata are the same age); principle of superposition (assume lower rock layers are older, deeper artefacts are older); index fossils (fossils widely found but only present for a limited time on Earth, match index fossils from various locations with known dates).	6

Descriptor

Marks

3 marks for each technique named and described (any 2 of): stratigraphy (study the rock strata/layers, match similar strata to other strata already dated/artefacts in the same strata are the same age); principle of superposition (assume lower rock layers are older, deeper artefacts are older); index fossils (fossils widely found but only present for a limited time on Earth, match index fossils from various locations with known dates).

Hair belt

Descriptor	Marks
Identifies Radiocarbon/carbon-14/C14 dating	1
States that it is based on the decay of carbon-14/C14 to nitrogen	1
States that the amount of carbon-14/C14 is fixed at death	1
States that the Carbon-14/C14 half-life is 5730 years	1
Explains that the ratio of carbon-14/C14 to carbon-12/C12 determines the age (years)	1

Q40b

8 marks

The mitochondrial DNA (mtDNA) in the plaited hair belt was associated with the DNA of today's traditional owners. Describe what mitochondrial DNA is and explain how it can be used to demonstrate a genetic relationship.

By definition, mtDNA is genetic material found within mitochondria. It is found in small circular molecules , and is inherited only from the mother.

In terms of use, mutations occur more readily in mtDNA than in nuclear DNA. Similarities in mtDNA between the traditional owner and the hair sample can be used to identify relatedness. The number of mutations in the mtDNA of the traditional owner and the hair sample is assessed. The less the diversity in their mtDNA, the more closely related they are.

Marking Criteria

Definition

Descriptor	Marks
States that it is genetic material found within mitochondria	1
States that mtDNA is found in small circular molecules/plasmids	1
States that mtDNA is inherited only from the mother/via the mitochondria in the mother’s ova	1

Use

Descriptor	Marks
States that mutations occur more readily in mtDNA (than in nuclear DNA)/higher rate	1
Explains that similarities in MtDNA between traditional owner and hair sample can be used to identify relatedness	1
States that the number of mutations in mDNA of traditional owner and hair sample is assessed	1
States that the less the diversity in their mtDNA	1
States that the more closely related they are	1

SCSA Human Biology Evidence for evolution

Example 1

Example 2

General

Stone Artefacts

Hair belt

Definition

Use

Frequently Asked Questions

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