Image Source – Making Human Insulin using genetic transformation
Today we reviewed genetic tools and techniques using Worksheet 31 and watched the video about Genetic Engineering. (YouTube, 7.24min) . We then completed a flow chart of gene transformation using the Biology animation Making Human Insulin.
How do cells communicate? In this area of study students focus on how cells receive specific signals that elicit a particular response. Students apply the stimulus-response model to the cell in terms of the types of signals, the position of receptors, and the transduction of the information across the cell to an effector that then initiates a response. Students examine unique molecules called antigens and how they elicit an immune response, the nature of immunity and the role of vaccinations in providing immunity. They explain how malfunctions in signalling pathways cause various disorders in the human population and how new technologies assist in managing such disorders.
Outcome 2 On completion of this unit the student should be able to apply a stimulus-response model to explain how cells communicate with each other, outline immune responses to invading pathogens, distinguish between the different ways that immunity may be acquired, and explain how malfunctions of the immune system cause disease.
In Area of Study 2: How do cells communicate? we study cellular signals (signalling molecules, signal transduction and apoptosis); responding to antigens (including antigens, innate and adaptive immunity and the lymphatic system) and the immune system (including diseases of the immune system and cancer immunotherapy). The following links are some resources for study in these topics.
Chapter 6: Cellular Signals
Chapter 7: Responding to antigens
Chapter 8: Immunity, immune malfunctions and immunotherapy
Last lesson we learned about the different types of signalling molecules (plant and animal hormones, neurotransmitters, cytokines and phermones). Today we will learn what happens when these signalling molecules reach their target cells, causing a response in the cell. Lipophobic (hydrophilic) signalling molecules cannot pass through the cell membrane, so they rely on complementary protein receptors that are embedded in the cell membrane. Once the signalling molecule – or ligand – binds to the receptor protein, secondary messenger molecules are released inside the target cell. Learn more about the specifics of signal transduction here:
Signal transduction from the Penguin Prof Channel
Signal transduction from Mr Bozeman (simple animated diagrams with commentary)
In the video above, observe one of the consequences of signal transduction – apoptosis or programmed cell death.
Learning intention: Students will understand the energy transformations from sunlight to chemical energy in the process of photosynthesis.
Watch the following videos and take Cornell notes. Especially pay attention to the products and reactants of the light-dependent and light-independent (Calvin cycle) parts of the reaction.
This fruit is from a genetically modified papaya plant, bred to reduce the risk of disease. How are genetically modified organisms created? (YouTube video, 5.31min)
Quizlet – Flashcards for Chapter 16
While genetic techniques have certainly provided health benefits to our society (disease diagnosis and therapies, production of insulin and increased production of more nutritious and disease resistant foods), there are also community concerns about the ways that these technologies are being used and the future consequences. ABC Splash have some short videos that outline some of the issues of genetic technologies:
Video Source (YouTube, 54.42 min)
“The theory of evolution by natural selection, first formulated in Charles Darwin’s book “On the Origin of Species” in 1859, is the process by which organisms change over time as a result of changes in heritable physical or behavioral traits.”
“Natural selection is the process whereby organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully expounded by Charles Darwin, and it is now regarded as be the main process that brings about evolution.”
What is the evidence for evolution? from Stated Clearly (YouTube, 11.21min)
Tree of Life video HD with David Attenborough (YouTube, 6.29 min) – Complete the student worksheet – Highlighting important stages in evolution.
The biological cell is not the static, neat drawing you find in text books, but a dynamic, differentiated, three-dimensional, living unit with many specialised processes occurring simultaneously. You should already know the basic structure and function of the cell, including the main organelles. This animated video shows some of the inner life of a cell – can you identify the cell membrane, embedded proteins and ribosomes? Over the next fortnight you will need to better understand the following biochemical cellular processes:
Welcome back and thanks for your patience while I have been on study leave. There are only two weeks left before the Unit 3/4 Biology exam on Friday 30th October, so you should have already done the following:
Some students have mentioned that they are having most difficulty remembering the cells involved and sequence of events of the cell cycle and immunology. These quick videos and other resources may assist with your revision:
Food chains illustrate the relationship between producers and consumers, showing the different trophic levels in an ecosystem. Because living organisms usually have more than one source of food, these food chains are often linked together, forming food webs. Food webs assist us to identify herbivores, carnivores, omnivores, scavengers, detritivores and decomposers in a community.
Not all relationships within an ecological community are predatory or feeding relationships. Some important relationships are parasitic, mutualistic (both organisms benefit), commensalism (one benefits, the other is not harmed) or parasitism (one benefits and the other is harmed, but usually not killed).