IQ1 has asked us to focus on the abiotic and biotic factors that affect ecosystems...

We are now asked in IQ2, to focus on what evidence have scientists been able to analyse to determine why ecosystems in the past changed.

This dot point requires that we analyse Aboriginal rock paintings, rock structure and formation (do you remember learning about The Rock Cycle in Year 8 Science!), and, ice core drilling. We need to learn what these processes are, how accurate are they, and how have they helped scientists to piece together the features and changes in past ecosystems.

ACTIVITIES: 

1. Watch the videos attached to the left and below this text box.

2. There are a number of websites and information to the left and below this textbox - use the information to develop your study notes.

3. Complete the worksheets on 'Evolutionary ecosystems' and 'Ice core data'.

Read and complete questions on pages 554-560 of the Pearson Yr 11 Biology textbook. 

Cast your mind back to Year 10 science when you learned about radioactivity (including radioactive decay)...

This dot point asks us to investigate and analyse radiometric dating and gas analysis as technologies that scientists use to determine evidence for past changes in ecosystems.

DEFINE 'gas analysis': Gas analysis is used to extract information from tiny bubbles containing atmospheric gas that becomes trapped in the ice cores.

The ice can be crushed to release the trapped gasses, which are then separated out by a gas chromatograph.

Isotopes can be identified by Isotope Ratio Mass Spectrometry.

Reference: https://www.matrix.edu.au/beginners-guide-to-year-11-biology/ecosystem-dynamic/ 

DEFINE 'radiometric dating': Radiometric dating can be used to determine the absolute age of a material such as rocks or fossils.

An example of a radioisotope is Carbon-14 which is taken up by organisms while they are alive and upon their death begins to decay to become Carbon-12.

The ratio of Carbon-14 to Carbon-12 continues to change consistently over time, so this ratio can be used to estimate the age of the sample.

Reference: https://www.matrix.edu.au/beginners-guide-to-year-11-biology/ecosystem-dynamic/ 

ACTIVITIES: 

1. There are a number of websites and information to the left and below this textbox - use the information to develop your study notes.

2. Complete the worksheet on 'Radiometric Dating'.

3. Read and complete questions on pages 555-557 of the Pearson Yr 11 Biology textbook.

In Australia, there are many different organisms that are unique to this country. However, fossil evidence suggests that these organisms were once not only located in Australia but also in other continents (such as South America and New Zealand). Fossil evidence supports the theory that the continents were once connected as Gondwana. Fossils of Australian mammals were also much larger than present-day mammals, suggesting that these organisms have evolved to the size that they are in the present-day. 

This dot point requires that we review and analyse this evidence of evolution of Australian organisms.

We will focus on case studies of the:

• Platypus or Wombat (this addresses 'small mammals' in the syllabus)

• Eucalyptus plants (this addresses 'sclerophyll plants' in the syllabus)

ACTIVITIES: 

1. Watch the videos attached to the left and below this text box.

2. There are a number of websites and information to the left and below this textbox - use the information to develop your study notes.

3. Complete the worksheet on 'Living evidence of ecosystem change'.  

4. Read and complete questions on pages 561-566 of the Pearson Yr 11 Biology textbook.