1-1A Lecture Notes 8/31/21 ● ● ● ● ● ● Title Slide ○ Defining Life Key Skills ○ Take useful notes/answer lecture questions ○ Identify & define the properties that all living things have in common ○ Apply these properties to decide whether a given entity is alive Rosalind Franklin 1920-1958 ○ Took x ray images of DNA ○ Determined DNA has a double helix shape What do we mean by “life” ○ I think that when biologists talk about something being alive, they are referring to something being able to interact with their environment, or have some sort of higher functioning that keeps them from being completely unresponsive. In animals and humans it also may refer to brain activity and functions within the body, but in plants it could be referring to energy produced within the system that keep the plant alive Which of the following is/are alive? ○ Dead fish ■ No, the dead fish isn’t alive because if the fish is dead then the functions within the fish that keep it alive are no longer operational and the cells are no longer alive as well. ○ Viruses ■ I don't think viruses are alive because the virus is mainly made out of bacteria. While they can interact with their environment I don’t think they are living because they don’t have any higher functions like a living organism would. ○ Acorn ■ Yes I think that an Acorn is alive because it is made up of cells, and it is organic matter. I don’t know if it would make a difference if the acorn was still attached to the tree. I think that if it was still attached to the tree then it is alive, but if it’s fallen off the tree then it isn’t. ○ Candle flame ■ No, I don’t think that a candle flame is alive because it’s not made up of cells, and not organic matter. ○ Mouse ■ Yes the mouse is alive because a mouse is made up of cells and is able to respond to its environment. Structure and function ○ One way to define life ○ Structure- how the pieces of an organism are arranged ○ Function- what those pieces do ○ Living things organized into 1 or more cells, and contain DNA ○ ● ● ● ● Living things take in/release energy, transform matter, reproduce and evolve, respond to their external environment, and regulate their internal environment (homeostasis) Cells contain DNA ○ Cell contains nucleus, nucleus contains chromosomes (protein+DNA), chromosomes carry genetic info. Living things perform homeostasis ○ homeostasis - the ability to maintain a livable environment inside of your body or cells despite differences in the outside conditions Virus ○ Can evolve, ○ Uses RNA not DNA ○ Can't copy itself, or respond to environment ○ Has fatty membrane similar to cells ○ Can’t maintain homeostasis Answer to question ○ I think that the debate as to whether a virus is alive could go either way. It could be considered alive because it can evolve, has a fatty membrane similar to a cell’s. However, I don’t think that the cell is alive because it doesn’t meet all the criteria to define it as a living thing. It doesn’t have DNA, it can’t maintain homeostasis, and it can’t copy itself or respond to its environment. 1-1B Lecture Notes ● ● ● ● Title Slide ○ Principle an Organization of Biology Key Skills ○ Explain what is meant by each ■ Structure reflects function ■ DNA makes RNA Makes Protein ■ Follow the Energy ■ Evolution Creates Diversity ■ Complex Systems show Emergent Properties ■ Apply these themes to specific biological events ○ Recognize and describe the levels of organization of life from smallest to largest. Principle 1: Structure of living things suits their function ○ What is another example of a living structure with a shape that reflects its function? ■ Another example of a living structure with a shape that reflects its function is a shark’s teeth. They are triangular in shape and serrated which makes it easier for them to cut the flesh of their prey into smaller pieces, since their prey usually consists of larger mammals and other sea creatures. Principle 2: DNA makes RNA; RNA makes Proteins (The Central Dogma) ○ DNA stores long term info which can be copied into shorter term messages (messenger RNA), which is then translated into proteins. ● Principle 3: Follow the Energy ○ Energy is never created or destroyed, only transformed from one form to another ● Principle 4: Evolution Creates Diversity ○ Changes in living populations over time give rise to new species. ● Principle 5: Complex Systems show emergent properties ○ Emergent properties come when different parts of a system interact. (example can be the human body) ● Organization of Living Systems ○ Smallest level- atoms ○ Largest- biosphere; all life on earth and its environment ■ Biosphere contains many ecosystems, these ecosystems hodd communities or different organisms, in these communities are populations of specific species and each species has many individual organisms with different organ systems. These organ systems contain individual organs, which are made of groups of cells called tissue. These individual cells have their own organization. Inside these cells, are organelles, which are made of molecules like DNA, which are in turn made of atoms. ○ Organism vs. Population vs. community, vs ecosystem ■ Organism, C ■ Population, D ■ Community, A ■ Ecosystem, B ○ In your notes, ask a question that might help clarify what the sentence "The gostak distims the doshes" means. ■ What does gostak mean? ■ 1-1C Lecture Notes ● ● ● ● ● Title Slide ○ Scientific Methods Key Skills ○ Describe the steps of the scientific method and apply them to examples ○ Explain what it means to test a falsifiable hypothesis ○ Distinguish between a controlled experiment and having a control group ○ Design a simple experiment with a control group Towards what or whom did doctors direct this chant? ○ I think the doctors directed this towards the disease itself. How might the Chant have been Beneficial? ○ B, and C Placebo Effect ○ Believing that you are receiving treatment can help you feel better, despite not receiving actual treatment ● ● ● ● ● ● ● ● ● ○ If you want to test a treatment you have to control for the placebo Testing a treatment ○ Need a large number of patients who give informed consent ○ People need to be randomly assigned to an experimental group and control group ■ Experiential- receives treatment, control- doesn’t receive treatment ○ Must be a double-blind design (neither doctor or patient knows who is getting placebo) ○ Experient should be controlled for relevant factors (age, prior illness) ■ Making a controlled experiment ^ Does Vitamin C reduce cold symptoms? ○ First off, you would gather a large group of people, and to make sure that you have a controlled experiment, you must make sure that each participant is experiencing cold symptoms. Next you would need to randomly assign participants in the group to an experimental group, and a control group. The experimental group will receive vitamin c tablets, and the control group will receive placebo pills such as sugar pills. The experiment must be a double blind experiment so that the results of the experiment are not skewed in any way. Lastly, each group's symptoms will be monitored over the course of a week and we will compare results between groups. If we observe that there is significantly more correlation between the experimental group and faster relief of symptoms, then we can come to the conclusion that vitamin c does reduce cold symptoms. Rules for Hypotheses ○ No hypothesis can be proven 100% ○ It is an explanation that can be correct and that you can find evidence for ○ A scientific hypothesis must be falsifiable via testable predictions What are Scientific Methods? ○ All of the above What are scientific methods ○ There is not just one kind of scientific method Write two hypotheses as to the cause of Minamata disease in your notes. ○ The people got sick because their drinking water became contaminated with a water-born disease, which then spread from person to person through the air. ○ The people got sick because similar to the bubonic plague, the cats carried the disease which then spread from the animal, to the humans, and from there people spread it to others. If your hypothesis is testable, it should be possible to make falsifiable predictions based on them (if/then statements) Make a hypothesis as to where the mercury in the bay came from ○ The mercury levels in the bay rose due to the contamination from coal power plants. Question ○ ○ Is the virus considered alive or not? I was really interested in that and I don’t know the answer, and I’m not leaning in any particular direction, so I was wondering if you would like to weigh in on it? Can DNA be damaged, and if so can it be repaired? Also what happens if it does become damaged?
