CFE ADVANCED HIGHER BIOLOGY. GOOD MORNING! A poor man is sitting in a pub. He sees that the man next to him is extremely rich. Poor man: “I have an.

Unit 3

Cfe Advanced higher biologyGood morning!A poor man is sitting in a pub. He sees that the man next to him is extremely rich. Poor man: I have an amazing talent; I know almost every song that has ever existed. The rich man laughs. Poor man: I am willing to bet you all the money you have in your wallet that I can sing a popular song that includes your daughters name.The rich man laughs again. Rich man: Okay, you have no chance! My daughter's name is Gulsum! The poor man goes home rich.What song did he sing?

Unit 3Investigative Biology Scientific principles and process a) Scientific method Investigative Biology SQA

Success CriteriaExplain why scientific theories should be falsifiable.Use an example to describe the scientific method.Explain the Null HypothesisScientific theoryWhy is it important that science is done in a reliable and methodical way?Why is it important that recorded science is reproducible from the methods described in a journal?Why is it important that all science is peer reviewed before publication?

A little scientific test...Each card has a letter on one side and a number on the other.Your task is to determine whether all cards with a vowel on one side have an even number on the other.You can only turn over 2 cards.Which do you turn?

Good morning!The day before yesterday, Ellis was 7 years old. Next year, she'll turn 10. How is this possible?

The basis of scientific thinkingA scientific statement is one that is capable of being falsified or proved wrong by evidence.A good scientific theory would have two features:Falsifiable but when you attempt to prove it wrong it stands up to scrutinyBold being bold makes it more prone to falsification and it try's to explain more than a piddly little idea.A good theory has withstood many attempts to disprove it.

A test that would disprove gravity would be if we let go of an object and it did not fall.

14evolutionFalsification of Darwinian Evolution If there were a single hippo or rabbit in the Precambrian, that would completely blow evolution out of the water. None have ever been found. Human DNA should be more similar to great apes than other mammals. If this is not the case, then common descent is falsified.

Scientific theoryFor any scientific theory to be falsifiable it must be open to criticism from other scientists.Science is therefore a public activity open to criticism so that flaws in theories can be spotted straight away and new better theories take their place.Good morning!A very famous chemist was found murdered in his kitchen today. The police have narrowed it down to six suspects. They know it was a two man job. Their names: Felice, Maxwell, Archibald, Nicolas, Jordan, and Xavier. A note was also found with the body: '26-3-58/28-27-57-16'.

Who are the killers?

HypothesesScience is the gathering and organisation of testable and reproducible knowledge. In the scientific cycle, hypothesis testing involves the gathering, recording and analysis of data, followed by the evaluation of results and conclusions. New hypotheses may then be formulated and tested.evaluationScientific knowledge can be thought of as the current best explanation, which may then be updated after evaluation of further experimental evidence. Failure to find an effect (i.e. a negative result) is a valid finding, as long as an experiment is well designed. Conflicting data or conclusions can be resolved through careful evaluation or can lead to further, more creative, experimentation. The null hypothesis (the independent variable does NOT make a difference) can be used in the further design of experiments to investigate another possible effect.

The null hypothesisQuestion: Does a training program in driver safety result in a decline in accident rate? Hypothesis: People who take a driver safety course will have a lower accident rate than those who do not take the course. Null Hypothesis: There is no correlation between driver safety courses and accident rate

The null hypothesisA study was conducted to find out if zinc supplements reduced the severity of colds and influenza compared with not taking anything.What would be the null hypothesis?

What would be the alternate hypothesis?Taking zinc supplements does not effect the severity of colds and influenzaTaking zinc supplements reduces the severity of colds and influenzaThe null hypothesisA vaccine made from tumour cells was administered to people with malignant melanoma - a deadly form of skin cancer. The vaccine was given to people whose melanoma had spread. What would be the null hypothesis?

What would be the alternate hypothesis?The vaccine has the same effect on the melanoma as a standard treatmentThe vaccine is more effective in increasing the life expectancy of people with malignant melanoma than other treatmentsThe endless cycle!Once a valid theory has been developed the process of the scientific cycle starts again as new questions and observations arise as a result of the developed theory.Hypothesis testing.Gathering, recording and analysis of data.Evaluation of results and conclusions.Verification of ideas.This cycle is endless and provides for a very creative and dynamic aspect to scientific enquiry.

A brief history of The plasma membrane!Membranes are one of the most common features of the biological world. With the exception of some viruses, all living things depend in one way or another on membranes. They surround cells and separate cellular contents from the external environment. Membranes also form special spaces, or compartments, within the cytoplasm that separate various cellular processes. Without membranes, life as we know it would likely not exist.Franklin conducted an experiment on the effects of oil on the surface of water. He added a small amount of oil to the water in a small pond in Clapham Common. Immediately he noticed that the oil spread in a thin film over the surface of the water until a large portion of the pond was "smooth as a looking glass"Franklin's experiment was repeated by Lord Raleigh. In 1890 Lord Raleigh conducted a series of quantitative experiments with oil and water. He was able to carefully measure the area to which a known volume of oil would expand and also calculated the thickness of the oil film

The following year, however, he received a letter from a German woman named Agnes Pockels, describing some experiments that she had conducted in her kitchen. Agnes Pockels, it seems, had developed on her own with little training and support from others in the scientific establishment, a device for carefully measuring the exact area of an oil film.Charles Ernest Overton was working on a doctoral degree in botany at the University of Zurich. Overton discovered quite accidentally, some important properties of membranes. His research was related to heredity in plants and in order to complete his studies he needed to find substances that would be readily absorbed into plant cells. He found that the ability of a substance to pass through the membrane was related to its chemical nature. Nonpolar substances, Overton discovered, would pass quickly through the membrane into the cell. This discovery was quite contrary to the prevalent view at the time that the membrane was impermeable to almost anything but water. Based on his studies of how various molecules pass through the membrane, Overton published a preliminary hypothesis in which he proposed: (1) that there are some similarities between cell membranes and lipids such as olive oil, and (2) that certain molecules (i.e., lipids) pass through the membrane by "dissolving" in the lipid interior of the membrane.

1917 Irving Langmuir, trained in physical chemistry doing research on molecular monolayers. His research eventually turned to lipids and the interaction of oil films with water. Using an improved version of the apparatus originally developed by Agnes Pockels (generally referred to today as a Langmuir trough), he was able to make careful measurements of surface areas occupied by known quantities of oil. Langmuir published only one paper on molecular monolayers. He proposed that the fatty acid molecules form a monolayer by orienting themselves vertically with the hydrocarbon chains away from the water and the carboxyl groups in contact with the surface of the water. As it turns out, this was a key piece in the puzzle of understanding lipid bilayers and membranes as well. In their classic experiment, Gorter and Grendel extracted the lipids from red blood cells with acetone and other solvents. They were able to demonstrate that lipid molecules could form a double layer, or bilayer as well as a monolayer. Further, they were able to show that the surface area of the lipids extracted from the red blood cells was about twice the surface area of the cells themselves.

The first membrane model to be accepted by the majority of scientists was proposed by Danielli and Davson in 1935. He worked at Princeton University from 1933-35 with E. Newton Harvey, an expert in the area of cell surface studies. Working in Harvey's lab, Danielli had found that proteins could be adsorbed to oil droplets obtained from mackerel eggs. This finding would later become a major component of the membrane model proposed by Danielli and Davson. In 1935 Danielli returned to University College in London where Hugh Davson, a physiologist, was working. It was through the association of these two that the first membrane model originated.The model proposed by Danielli and Davson was basically a "sandwich" of lipids covered on both sides with proteins

The unit membrane model was eventually replaced in the early 1970s by the current model of the membrane. This model, known as the fluid mosaic model, was proposed by biochemists S. J. Singer and Garth L. Nicolson. The model retains the basic lipid bilayer structure first proposed by Gorter and Grendel and modified by Danielli and Davson and Robertson. The proteins, however, are thought to be globular and to float within the lipid bilayer rather than form the layers of the sandwich-type model. It has a long history. Like most of modern science, the fluid mosaic model resulted from the cumulative work of numerous individuals. Current biology textbooks, however, generally ignore the historical development and present the model almost as if it were a recent discovery.Success CriteriaExplain why scientific theories should be falsifiable.Use an example to describe the scientific method.Explain the Null Hypothesis