Biology Paper 1 EdexcelWatch
-Look over the spec to see what you don't know, its always great to search up the sentence word for work because there are sides dedicated to answering each spec point
-Do at least 2 practice papers before the exam and mark it yourself
Just try learn the stuff from the markschemes because keywords are a great way to gain points
bold= super important
bold+italics= you must must must know this
Human Circulatory System
Any plant experiments
Human Immune System
Human Digestive System
That should give you a good start. Just use your textbook. Write down anything you know about those. Then look at the spec/your textbook and see what you do not know. Also, this lady is awesome if you want a quick summary of the whole course:
Lastly, there are several key topics that you probably need to know the keywords for:
selective breeding/ natural selection
Micropropagation standard answer:
Take a small cutting from the plant (explant) and put it in a sterile medium of agar jelly with plant growth hormones in it. Once roots start to develop transfer the callus into a new medium with different plant growth hormones that will stimulate the growth of shoots. Then transfer the plant into an intermediary greenhouse with ideal conditions (eg optimum temperature) before transferring out into the real world.
Genetic engineering standard answer:
Take a piece of the DNA of the organism that has the desired gene and cut out the desired section of DNA/allele with a restriction enzyme. Stick it into a plasmid which acts as a vector (by using an enzyme called DNA ligase). Insert the plasmid into the bacterium. Allow the bacteria to reproduce in a fermenter under ideal conditions for their enzymes (temperature/ph). As the bacteria reproduce and live they will produce insulin (names example, adjust in accordance to case. Don't start talking about bacteria if the question is about genetically modifying an animal. This only applies if you want to produce something from the bacteria like insulin. Otherwise apply the stuff about DNA ligase, restrictions enzymes and... that's about it. And vectors, but don't say plasmids ).
Cloning Standard keywords and basic step in simple words:
- You have three sheep (Ally, Bonny, and Clara)
- You want to produce a baby that is identical to Ally
- You take a body cell from Ally and you take the nucleus out of that cell. You use the body cell and not an egg cell because it is diploid.
- You take a cell from Bonny. You'll use a gamete (ie an egg). You enucleate that cell (this means you remove the nucleus)
- You then use electricity to fuse Ally's nucleus and the enucleated cell of Bonny together. This fertilizes it.
- You allow the cells to divide by mitosis
- You implant the embryo into a surrogate mother
Selective breeding/natural selection keywords (all you really need is the keywords, the main logic is fairly easy to figure out)
-randomly caused mutations (leading to a desirable/advantageous trait)
-survive more and/or breed more
- produce more offspring
- mass DNA/ allele to offspring
-over MANY generations that trait becomes dominant as the process repeats
If they ask you about why if you draw a graph of enzyme efficiency and its relation to temperature/ph it keeps increasing, there is a peak and then it suddenly drops here are the main key words to use:
- optimum ph/temperature
-particles gain more kinetic/heat energy
-eventually the particles move so fast that they change the shape of the enzyme
- this causes the shape of the active site shape to change
-this means that the lock and key modelno longer fits
- this means that the enzyme has denatured.
After you've learend all of the following: did the topics, gave the video a go (this is optional) and the memorized these answers/main ideas you will probably get at least a C. After you do that just go through the rest of the spec and see what more you are missing.
Good luck there