VCE Biology

Unit 3 & 4 Biology at Hawkesdale P12 College

VCE Biology

Recombinant DNA technologies

July 29, 2014 · No Comments · Biochemistry, DNA, genetics, Unit 4 Biology


Image Source

On Monday we had the opportunity to connect with the Gene Technology Access Centre via the video conferencing equipment, Polycom. Nicole and Frazer facilitated a great session about recombinant DNA technology, including a demonstration of gel electrophoresis to determine if genes had been successfully inserted into a plasmid.

Did you know that humans have the same gene sequences as other organisms?

  • 61% similarity to fruit flies
  • 99% similarity to mice
  • 99.9% similarity to chimpanzees

The human genome has 22 pairs of autosomes and 1 pair of sex chromosomes (XX in females and XY in males). Chromosomes exisit in the nucleus (as single strands) and there is also some (maternal – passed down from the mother) DNA in the mitochondria, which is circular. Prokatyotes (bacteria) also have circular DNA called ‘plasmids’.

Sea jellies have a gene that codes for a protein that is luminescent, called a “green fluorescent protein”. This gene is a useful marker, to determine if other genes have been successfully introduced to an organism.

Restriction enzymes (used for ‘cutting’ DNA) are used to open the plasmid, the new gene is inserted and then a DNA ligase is used to stick the ends together. We are using four different restriction enzymes (EcoRY13; BamH1; Nhe1 and Sma1). The DNA sequence at a restriction site is a palindrome – reads the same forwards and backwards. Some restriction enzymes cause ‘sticky’ ends (uneven or with a tail – exposed base pairs) while others cause ‘blunt’ ends (no overhanging base pairs). Once the new gene is inserted, complementary base pairs are joined by hydrogen bonds – or ‘pasted together’ with DNA ligase.

This is the process we will model using the paper cut-outs:

  1. E.coli is a bacteria that can be resistant to various antibiotics (eg. Amp R = ampicillin resistant).
  2. Cut the plasmid using a restriction enzyme.
  3. Insert the gene of interest into the plasmid, stick it together and produce the recombinant plasmid, which should contain the ampicillin resistance gene as well as the “GFP” (green fluorescent protein) gene.
  4. To test if the recombination has been successful, we need to use the restriction enzymes to produce various lengths of DNA. These are then pipetted into ‘wells’ in the gel. Because DNA is a negatively charged molecule, we load the wells at the negative end and attach the positive wire to the other end, so that the pieces of DNA a drawn through the gel matrix to the other side. The longest pieces move more slowly and travel the shortest distance, while the shortest molecules move most quickly through the gel and travel the greatest distance.


“Pop!” goes the corn genetics

July 13, 2014 · No Comments · genetics, Unit 4 Biology


Image source

Go to the Gene Technology Access Centre site and watch the three videos:

  1. A Short History of a Very Important Plant
  2. Sex in Grass and
  3. Exploring a di-hybrid cross

Answer the questions on the worksheet “Human intervention for the domestication of plant species”.


Mendel’s Peas

June 24, 2014 · No Comments · genetics, Unit 4 Biology

Learning Intention: Students will understand the significance of Gregor Mendel in the history of genetics and be able to use the following terms correctly: dominant, recessive, alleles, genotype, phenotype, homozygous, heterozygous, cross-pollination, self-pollination and F1 generation.

Success Criteria: Students will complete the following three activities and be able to describe what they have learned in a class discussion.

Gregor Mendel (1822-1884) was an Austrian monk who is known as the father of modern genetics due to his experimental work with plant hybridization. It was Mendel who first coined the terms “dominant” and “recessive” and he formulated generalizations that have become known as “Mendel’s Laws of Inheritance”. “Mendel’s Pea Genetics – Experiments that changed the world” is a twenty-five minute documentary that describes his life. Complete the following three activities:



DNA makes RNA makes Proteins

June 23, 2014 · No Comments · Uncategorized


Image Source

If DNA is the ‘blueprint’ of a living organism, RNA is a photo-copy of the blueprint (a working plan, if you like) and amino acids and proteins are the building materials. The human genome contains around 30 000 genes, each of which codes for one protein. There are three main processes in turning DNA into proteins – Replication of the DNA, Transcription (DNA to RNA)  and Translation (RNA to proteins). Read about Replication, Transcription and Translation at atdbio. DNA is replicated in the nucleus, prior to mitosis and meiosis. DNA in the nucleus of all eukaryotic cells must then be ‘transcribed’, forming a complementary RNA strand that travels out of the nucleus, into the cytoplasm. From the single strand of messenger RNA, a ribosome ‘reads’ the triple codon and ‘chooses’ a specific amino acid that corresponds with the triplet code. Transfer RNA carries amino acids to the ribosome and serves as the link between the RNA molecule and the forming polypeptide.




Introduction to Genetics

June 17, 2014 · No Comments · genetics, Unit 4 Biology


In this class you are going to create your own word cloud and mind map to show me what you already know about genetics. Go to the google doc at and add at least ten words that come to mind when you think of ‘genetics’. Copy and paste all the terms into Tagxedo and customise your word cloud. Download a copy and send it to me. Now you have two choices:

  1. Go to and create a mindmap using the key terms from Chapter 9. Download and send a copy.
  2. Go to Quizlet and create a set of flashcards using the terms and definitions from Chapter 9. Send me a link to your work. The Quizlet below was created by Mr Flattery and can be used and adapted.


Week 8: Unit 4: Continuity and Change

June 8, 2014 · No Comments · genetics, reproduction, Unit 4 Biology


Image Source

Area of Study 1: Heredity

This area of study focuses on molecular genetics and the investigation not only of individual units of inheritance, but also of the genomes of individuals and species. Students investigate inheritance in asexually reproducing organisms and the mechanism and patterns of transmission of heritable traits in sexually reproducing organisms.

Students examine the process of meiosis in terms of inputs and outputs and, in accounting for variations in offspring, consider the interplay between genotype and environmental factors, the significance of mutations in DNA, and the relationship between alleles.

All prokaryotes reproduce asexually, without the formation and fusion of gametes. Many plants and fungi also reproduce asexually, meaning that they are genetically identical to their parent. Types of asexual reproduction include:

  • Binary fission (bacteria)
  • Budding (yeast)
  • Vegetative reproduction (strawberry runners, aloe)
  • Sporulation (fungi, algae, ferns)
  • Fragmentation (annelids, sea-stars)
  • Parthenogenesis (some lizards, sharks and stick-insects)

This week we will begin to study molecular genetics – the foundations of ‘who we are’, before environmental factors play a role. Half your DNA comes from your mother (eggs produced in the ovaries) and half from your father (sperm produced in the testes). This DNA contains genes and genes code for proteins, so the gametes (eggs and sperm) contain the genetic instructions that cross the generation gap, giving you the characteristics that you share with your biological parents.  The genetic instructions in an organism make up it’s genotype, which is expressed visually as the phenotype (physical, biochemical and physiological traits).

Humans have 23 pairs of chromosomes, often referred to as the diploid number or 2n=46. The image above is called a karyotype, used to assist with chromosomal analysis – is this one from a male or female? Chromosomes can be distinguished by their relative size, position of the centromere and the patterns of light an dark bands. Matching pairs are said to be homologous. A human male has non-homologous sex chromosomes (XY).

More Resources for this Unit:



Good Revision Resources

May 31, 2014 · No Comments · revision, Uncategorized, Unit 3 Biology


Image source

If you only check out two of these, make sure it is the first and last ones!



Unit 3 Exam Revision

May 31, 2014 · No Comments · Exam tips, Uncategorized, Unit 3 Biology

By now, students should be well immersed in study for the Unit 3 exam in less than two weeks time. It is essential to create a study timetable that allows time for school, work, sport and study for each subject. Make sure you understand the key terms and definitions and can apply the various concepts included in “Biological Macromolecules” and “Detecting and Responding“.
Many students find that creating Flashcards helps them to remember key terms and concepts. You can do this online at Flashcardsdb and Quizlet and use the cards for revision.
Another great way to study concepts is to create concept maps, such as these hand-drawn ones at this site. You can also create concept maps online using FreeMind, Inspiration or
Quiz Revolution (previously called My Studiyo) is another online tool you can use for exam revision. Use this site to create multiple choice questions, with or without images, to test student knowledge.

Before your examination, make sure you:

  • get enough rest and sleep
  • eat sensibly, don’t skip meals or try to fill up on snacks – active brains need a balanced diet
  • check on the starting time and allow plenty of time to get to your examination centre
  • check that you have everything you need – make yourself a list

The materials you should take into the examination room with you include:

  • one or two highlighters – you can use these to highlight action words that guide you in how to answer each question; key information and data in each question and questions that you know you may want to come back to during your 5 minutes checking time
  • clear (transparent) ruler
  • two pencils (with extra lead or a sharpener)
  • eraser
  • scientific calculator (either with new batteries or a back up scientific calculator)

Tips for during the examination

Using your reading time: One strategy that works for many students during the 15 minutes of reading time is to:

  • Spend the first minute or two simply ‘flicking through’ the examination paper to gain a snapshot of the length of the paper, layout of questions, occurrence of figures such as graphs, tables and drawings.
  • Check all pages and questions are present as described on the front cover of the examination booklet
  • Follow this up with scanning each question very briefly to determine its focus; for example, is the question related to biological macromolecules, homeostasis or signalling molecules and ask yourself whether the question requires a definition, analysis of data, evaluation with evidence or is another type of question. (This may only require 6-8 seconds per question, and sometimes less.) It is not necessary at this stage to begin solving for the answers but simply allow your brain to begin processing the information.
  • This will leave you with about five minutes to carefully read particular questions, during which time you may like to start mentally outlining your answers.

Once writing time begins, try to stay calm. You might like to start with a question that you feel is straightforward to answer. Use your highlighter to identify the ‘action words’ (such as name/nominate, describe, outline) to help keep you on-track as you respond to each question.

Students are warned against listing or describing more examples than asked for in a particular question, if you think of a better quality response than you first wrote, it is recommended that you clearly identify (by highlighting, underlining or circling) the examples you wish the examiner to assess.

If you find yourself writing much more than the lines and space provide for in a particular question, then it is possible that you are writing too much and you should consider using dot points. It is important that you allow yourself sufficient time. Attempt all questions, even if you are not entirely confident of your answers – examiners cannot award marks to empty spaces.

(This post was adapted from an article by Hayley Bridgewood and Gerry Healy, VCE Examiners).


Week 6: The Immune Response

May 29, 2014 · No Comments · Functioning Organisms, Immunology, Unit 3 Biology

Image Source

If you suffer from allergies, you may be familiar with the image above. This person is having a ‘skin prick’ or ‘scratch’ test, in which a tiny drop of the possible allergen is pricked into the skin and the reaction measured. Allergens can be a wide variety of substances, from pollens and dust mite faeces to eggs, milk and nuts. Up to 40 different substances can be tested at once.

This is the link to our Google Presentation on the Immune System. I have allocated one slide with a topic for each pair of students. You can add another slide if you need to, but just a few brief dot points under the heading will be sufficient.

More sites for revision of Unit 3: Area of Study 2:



Mycoplasma mycoides

May 22, 2014 · No Comments · Cell biology


Illustration by David S. Goodsell, the Scripps Research Institute

This amazing watercolour painting shows an entire Mycoplasma mycoides cell, a bacterium that causes lung disease in cows, is painted with a brilliant green membrane that brings grass to mind. Inside, bright yellow DNA curls next to protein-builders in purple and blue. In life, this bacterium is about 250 nanometres in diameter. Click on the link to identify the membrane proteins, enzymes and other protein synthesis organelles. How beautiful is this?!

Read more about Art and Science here.