For homework, please watch the following video from Mr Anderson’s Bozeman Biology channel on Youtube and complete the Google form I sent you. I’ve also embedded the form below the video, but you can only see it when you are logged into your IST gmail account.
I’ll add more later, but for the moment, please use this lab report planner to develop the investigation you will design into photosynthesis and respiration in Philodendron hastatum and Sansevieria trifasciata.
Below is a link to the planner as a Google form. When you complete the planner and click ‘submit,’ I will receive a digital version of your responses, which means I can then quickly see what you’re planning for your investigation and give you some timely feedback in class. ***Please note that you must be signed in to your IST Gmail account in order to see and use the planner form!
Click on the following link to download a MS Word version of the planner. It covers all parts of the lab report process in MYP science and is a little more detailed than the embedded Google form above. Photosynthesis-Respiration Lab Report Planner
This week in grade 9 science, we’ll start the process of developing your investigations into photosynthesis and respiration in Sansevieria trifasciata and Philodendron hastatum plants. The first steps of that process are a couple of preliminary experiment to establish an understanding of these essential processes.
The experiment below is the one we’ll be doing in class on Thursday and Friday of this week. Please make sure you’ve read all the way through the procedure before we start in the lab!
You will submit digital versions of the data tables and the analysis questions for homework after you’ve finished this experiment. You may send them via email.
Well, today was a little wacky, with no electricity or projector, class photographs in the middle of one class, and virtually no air circulating in my room to make for a hot hot hot day at school. Add in the noise and distraction of holding class in the courtyard, and we have….well, we have a bit of a mess.
Just so we’re all on the same page of the biology unit, I thought I’d summarize the key points from today’s lesson on biological molecules. Below are the finer points of the lesson.
The 3 major functions of all biological molecules
Source of energy
chains of C, H, and O
supply all energy in cells and food chains
energy tends to be short-term energy (glycogen)
simple sugars such as glucose may build more complex molecules
some long chains of sugars, such as cellulose, are used for cellular structure
do not dissolve in water
long chains of C, H, O, and P
have more bonds than carbs, so they’re used for energy storage
slow release of energy
saturated fats: all single C-H bonds, tend to be solids
unsaturated fats: some C-C double bonds, tend to be liquids (oils)
Plants and animals are both eukaryotes, meaning they have distinct nuclei. (Bacteria, by contrast, are prokaryotes, which means they don’t have a nicely organized nucleus.)
Plants and animal cells have many other similarities: ribosomes, mitochondria, chromatin, cell membranes, smooth and rough endoplasmic reticula (ER), vacuoles, and Golgi complexes, among some other organelles we’re not studying in this unit. However, there are some fundamental differences between plants and animals on a cellular level:
cell wall in plants
chloroplasts (plastids) in plant cells
large central vacuole in plant cells
centrioles in animal cells
some differences in the structure and function of the Golgi complexes
Watch this video for a nice summary, and please do click on the links he posts at the end for a deeper explanation of the topics he covers.
The following video is a bit more ‘scientific’ and uses some nice computer animation to tour plant cells. It’s worth a quick watch, too.
Here’s an intriguing article about research into a new method of fertilizing food crops. Nitrogen is one of the key elements required for plant growth, but because it’s not found everywhere on the planet, people use nitrogen fertilizers to boost yields in areas with low nitrogen levels. Unfortunately, the Haber process (the industrial process of producing nitrogen fertilizers) requires large inputs of energy, which then means large outputs of greenhouse gases. Commercial fertilizers are also expensive, especially for low-income and subsistence farmers, and they often leach into rivers and lakes, causing eutrophication.
This potential discovery from the world of biotechnology could change food production in several important ways. First, the plants themselves would be able to ‘fix’ nitrogen directly from the atmosphere, essentially supplying their own fertilizer. Second, small-holder farmers (like most of the farmers in Tanzania) wouldn’t have to buy fertilizer anymore, which means they’d have more money to spend on things such as education and health care for their families. Third, reducing the energy demand for the Haber process would lessen our carbon footprint and our contribution to climate change. And lastly, the problems of eutrophication – lifeless, oxygen-starved lakes and streams – may also diminish.
Now that we’ve spent some time getting to know our key vocabulary in the biology sequence, let’s start to delve a little deeper into the links and relationships among those words.
The Cell Theory is one of the foundational ideas behind all of biology, and it is something you must be familiar with before starting any future classes in bio. There are 3 main postulates to the Cell Theory, which I’ve listed below.
All living things are made of cells.
All cells come from pre-existing cells.
The cell is the smallest unit of life.
Even though all living things are made of cells, not all cells are alike. Living organisms are classified into 5 kingdoms of life based on differences in their physiology and cell function. I think the link above and the image below nicely summarizes the way we classify living organisms.
In this unit we’ll look at one of the key distinctions among Earth organisms: the differences between plant and animal cells. The notes packet and diagrams you received in class contain the “official class notes” on this topic, so don’t lose them! You might also find the following items somewhat useful:
We will revisit these images when we dive into Topic 3, Subtopic 3.6 – Water Resources (‘dive in’ – get it? haha!), but they’re worth a read now. You’ll need to know some of these numbers for your IB Exam!