How many NESA Biology questions cover Planning Investigations?

AusGrader has 39 NESA Biology questions on Planning Investigations, all with instant AI grading and detailed marking feedback.

NESA (HSC) Biology — Planning Investigations Questions & Answers | AusGrader

Q17

2022

QCAA

Paper 1

1 mark

Q17

1 mark

Students used quadrats to investigate biodiversity in a grassland community with scattered distribution of plant species. The students agreed on a counting criteria for each quadrat to

A

reduce the time taken to count the different species.

B

minimise statistical uncertainty.

C

ensure all strata were sampled.

D

minimise bias.

Q24

2023

SCSA

1 mark

Q24

1 mark

Most vinegar flies have wild type (reddish-brown) eyes. However, some mutants have white eyes and cannot see. Biologists conducted a laboratory experiment to compare the fitness of flies with wild type and white eyes.

The dependent variable in the experiment is the

A

laboratory conditions.

B

eye colour of the flies.

C

vision of the flies.

D

fitness of the flies.

Q22

2024

NESA

4 marks

Q22

A student designed and conducted a practical investigation to test for the presence of microbes in water and food samples.

Q22a

2 marks

Justify a safety precaution required to prevent infection when conducting the investigation.

The wearing of gloves to prevent contact with skin and the subsequent entry of pathogens into skin/mouth

Marking Criteria

Descriptor	Marks
Justifies a safety precaution used to prevent infection	2
Provides some relevant information	1
None of the above	0

Q22b

2 marks

Explain how the student could ensure the reliability of the investigation.

The student could repeat the experiment by using five plates to culture the same sample of food or water. This would mean the student could check that the results are similar in each test.

Marking Criteria

Descriptor	Marks
Explains how to ensure the investigation is reliable	2
Provides some relevant information	1
None of the above	0

Q21

2024

QCAA

Paper 1

7 marks

Q21

In 2014, a group of scientists surveyed a plant community and determined Simpson’s diversity index (SDI) to be 0.84. They returned to the same site in 2024 and collected this data.

Species	Number of individuals
A	133
B	96
C	256

Q21a

2 marks

Calculate SDI in 2024 using the formula $SDI = 1 - \left( \frac{\sum n(n-1)}{N(N-1)} \right)$ . Show your working.

$SDI = 1 - \left(\frac{(133 \times 132) + (96 \times 95) + (256 \times 255)}{485 \times 484}\right)$

$= 0.61$

Marking Criteria

Descriptor	Marks
determines SDI as 0.61	1
provides appropriate working	1

Q21b

2 marks

The scientists noted that species richness was the same in 2024 and 2014.
Infer how species evenness changed over the 10-year period. Justify your response.

Species evenness decreased over the 10-year period. SDI considers both species richness and evenness — the greater the species richness and evenness, the higher the SDI value. As species richness was the same in both years but SDI decreased from 0.84 to 0.61, it can be inferred that species evenness was lower in 2024 than in 2014.

Marking Criteria

Descriptor	Marks
infers that species evenness decreased over the 10-year period	1
justifies inference using SDI data	1

Q21c

3 marks

Describe how sampling could be used to collect data for this investigation.
Include at least two strategies to minimise bias.

Quadrats could be randomly placed throughout the forest, and the number and type of plants observed in each quadrat recorded. This data could then be pooled and used to estimate the total number of each plant species at the site. The researchers could ensure that at least 10% of the site is sampled (by considering number and size of quadrats) and use a random-number generator to decide where to place the quadrats.

Marking Criteria

Descriptor	Marks
describes an appropriate surveying technique	1
identifies one strategy to minimise bias	1
identifies a second strategy to minimise bias	1

Q4

2020

QCAA

Paper 2

6 marks

Q4

An ecologist investigated the species composition of mangrove trees in a natural mangrove forest and an adjacent 30-year-old planted mangrove forest.

Three 10 m-wide belt transects were sampled from inland to the sea for each of the forests, each covering 100 m on average and placed to cover various strata.

The species diversity of Forest A was determined using the Simpson’s Diversity Index (SDI):

$SDI = 1 - \left( \frac{\sum n(n-1)}{N(N-1)} \right)$

	Population count
Species	Forest A (natural)	Forest B (planted)
Grey mangrove	91	77
Red mangrove	23	14
River mangrove	11	8
Orange mangrove	3	0
Diversity	0.46	?

Q4a

2 marks

Use the SDI formula to calculate the diversity index for Forest B. Round your answer to two decimal places.

SDI
$= 1 - \frac{77(77-1) + 14(14-1) + 8(8-1)}{99(99-1)}$
$= 0.37$

Marking Criteria

Descriptor	Marks
Demonstrates correct substitution	1
States SDI = 0.37	1

Q4b

3 marks

Identify three reasons why the ecologist used a belt transect rather than line transects or randomly placed quadrats for collecting data to compare these two forests.

Belt transects are used for abundance and distribution of species. Random quadrats can be used for abundance, not distribution, and line transects can be used for distribution, not abundance.
Random sampling doesn’t take into account strata (different areas) and may not cover all areas of habitat equally, giving inaccurate measures of diversity and abundance.

Marking Criteria

Descriptor	Marks
States 3 reasons	3
States 2 reasons	2
States a reason	1
Does not satisfy any of the descriptors above	0

Q4c

1 mark

Identify one way in which the ecologist minimised bias in the sampling.

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