[Music] hi it's Mr Anderson and welcome to the last AP biology review as you can see from the setting I'm on the road I'm in a hotel uh but I wanted to shoot this last video as you get ready for the AP exam on Monday I got almost 500 questions from people around the world and so I want to try to answer the top 20 of those questions and then give shout outs to everybody so if you're looking for just a shout out you may want to go way to the end of this video um but the first thing I got was an overwhelming amount of thank yous from people around the world um thanks for making the videos and so thanks you for watching uh I I'm happy to hear that they've been helpful um it's always fun to see how many people are watching the AP Bio videos on the weekend before the AP exam so I hope it helps out um next was tons of questions about how's the exam set up and then what are some strategies that I could use and so a lot of you are going to be really nervous and so if we know more about the exam that'll help and so there going to be two parts to the test there's going to be a multiple choice portion and that'll take you 90 minutes to do they're going to be 63 multiple choice questions and then six Grid in questions um you'll be able to use a calculator on this and you'll probably have to use the calculator to do some of those math griding questions um so make sure you do all 69 of those questions um each of them are worth the same amount and so don't spend tons of time on one that maybe uh is confusing skip ahead um and just keep moving you should take about a minute on each question um lots of times the answer is not just going to pop out and so my students have found if you use process of elimination you can get rid of some of the bad answers and then just kind of make a guess always guess don't leave any blank um when it comes to the AP exam there's no guess penalty last year um oh this is what the Grid in looks like so what you would do is write the numbers here so if I want to put in 50 I would put a five and a zero here and then I would bubble in the five and the zero remember a computer is going to be grading all of these so make sure you have pencils ready to do that it doesn't matter if I write the 5 Z here or the 5 Z here it's going to be smart enough to figure that out and they'll give you a range in which your answers could be um as as you're filling in those answers and so again I would encourage you on multiple choice to work at PACE and make sure you answer all of the questions some of my students are pressed for time in that 90minut period of time um try to look at the setup figure out what's going and and make sure you read the question that's a big tip uh last year you had to get a 79% % or more on the multiple choice to get a five so AP exam you've probably heard is a tough test and so you should if you're really shooting for a five you should only be missing about one out of every five questions when it comes to the free response you'll get the questions and then you get 10 minutes to read the questions and so you're going to get two long free response and so it should take you over 20 minutes on each of those and then six of the short free response so you get 80 minutes so you can do the math on how long you should be taking um I would encourage you during that 10-minute period of time just try plan out the whole thing make sure when you're doing the free response that you're looking for those descriptive words they're telling you do you want us to explain or Justify if they say give two pieces of evidence make sure you're giving two pieces of evidence so really read the question over and over and make sure that you know what it's asking there will always be some mind-bending questions that are just confusing so it's always better again to just um make your best guess as to what the right answer is next one was Hardy Weinberg got tons of questions about Hardy Weinberg I'm not sure if you mean what it is probably how to do the calculations um I've done a video on how to do Hardy Weinberg calculations as well again what does it mean in a population that is large enough um doesn't have uh non-random mating doesn't have mutations doesn't have gene flow and doesn't have natural selection the alal frequencies will stay the same so if we break this apart P stands for the dominant alal Q stands for the recessive Al so let's say 10% of the alals are for red hair what perent would be for non- red hair it' be 90% these will always sum up to one what do these values stand for p^2 is the homozygous dominant so big H Big H for example 2pq would be big H little H and q^2 would be little H little H so a lot of people get screwed up because they try to solve this as some algebraic problem and so you can think of it like a punet square so let's imagine that if we if we go across the top that the P value is 0.5 so if we say it's 0.5 right here and the Q value is 0.5 and if we say it's the same on this side what does that mean it means that half of the genes would be half of each of those um different genes and so what percent would be Q ^2 down here you could just count the boxes and we'd find it be 25% but we can move that value back and forth and we can figure out the p^ S and the q^ squ and the 2pq so let me give you a setup let's say that 9% of the individuals have red hair what did I just tell you I told you the phenotype I told you this down here q^ squ and that's almost every problem is going to tell you that Q ^2 so if 9% have red hair I can set q^2 equal to 09 if I take the square root of that now I know that Q is.3 therefore p is going to be 7 once you know that you could figure out any of the other things so I'd know that P squar would be 49% or 049 and this would be 42% and so they're going to give you a problem since you have a calculator that's not as simple as that but you solve it the same way start with the q^2 solve for the Q and then find the other ones Ki squared got a lot of questions about Ki squar what kind of a question are you going to be asked to do ki squared I'd bet on one of these two things it's either going to be a genetics like a fly genetics question or it's going to be an animal behavior where animals are found at different times there was a question about that last year um what is the summation mean it means that you have to calculate the Ki squared value for each of the different data sets in your data um o stands for things that are observed and E stands for things that are expected so let's say I flip a coin a hundred times and I get 60 heads and 40 tails you can do a Ki squared analysis of that what did I just tell you those would be the observed values how would you figure out the expected values well if you flip a coin a 100 times you should get about 50 heads 50 tails and so you can use that to figure out Ki squ you use a null hypothesis which this is the one that I would always use there's no significant difference between observed and expected values in coin flips or in flower types or in fruit flies and so then you can use this chart and this will be on that formula sheet how do you read it well if we look at heads or tails there are two different types heads or tails and so if you take that minus one that'll always tell you the degrees of freedom and so in this case it would be one degree of freedom I would encourage you to use the 05 value right here and so the critical value would be 3.84 one let's say there are four chambers and we're looking at how fruit flies move between those four chambers then we would simply say that there are three degrees of freedom four chambers three degrees of freedom what would the critical value be it's going to be 7.85 815 so if you get a Ki squ value that's higher than that basically that says that something's going on and so we fail to accept our null hypothesis and so an example this could be an animal behavior set let's say we're counting pill bugs moving back and forth all you do is just get the mean on each side the mean in the wet the mean in the dry and you can see right here that this would be my observed values because I'm seeing that in the lab and here'd be my expected values next respiration got tons of questions about respiration what kind of organisms are doing those you know it's not just plants but it's animals and and parts of this glycolysis go way back so all life on our planet is using some form of glycolysis this diagram is a little too complex what's going on with glycolysis we're basically breaking glucose which is a six carbon molecule down into two perate molecules which are each three carbon what do we net out of this we make a little bit of ATP out of this where's the energy going the energy is going into a molecule called NAD or nadh and you can see it way back here when we get to oxidative phosphorilation what happens to that perate it again becomes something called acetel COA and then goes into the kreb cycle what's the big thing again don't learn all these intermediates that'd be silly what's the big thing that's going on in here is that we're giving off that carbon as carbon dioxide that's the carbon dioxide that you breathe out where's all this taking place it's in the Matrix or in the inside of that um mitochondria where's the big show when it comes to cellular respiration you can see NAD right here is dropping off an electron and it's going down the electron transport chain another thing that's made in the KB cycle is going to be fad and what's fad doing it's carrying other electrons in hydrogen they're dropping their electrons a little bit farther down but what are we using that energy to do we're using it to pump protons from The Matrix out into this inter membrane space of the mitochondria all of these positive protons don't want to be there and so as they flow back through through ATP synthes then we make ATP now what are some questions they could ask you well let's say we dye the carbon in glucose with some kind of a radioactive die or marker where are we going to find that well you should be able to figure out where's the carbon going and be able to answer application type questions like that when it goes to photosynthesis there are two parts to photosynthesis you have the light part which going to be the light reaction where does that occur in a chloroplast that's going to be in the thid membrane and then you have the Calvin cycle what's going on there that's going to take place in the stroma and that's where we're actually making the sugars and so just like the electron transport chain in respiration is the most important part what would be the most important part here it's going to be in that light reaction where we're harnessing the power of that light how does that work basically light's coming in here and here so it's coming into a photosystem what's a photosystem it's a protein with a bunch of uh chlorophyll molecules on the inside of it what's happening is the electrons are getting excited and as those electrons get boosted to a higher level they go down an electron transport chain and we use the energy of that to pump protons to the inside of the membrane does that sound familiar it's just like respiration but inside out what happens to eventually those protons they flow out through ATP synthes and then we make ATP what are we using the energy of that ATP to do let me go back for a second we're using the energy of that ATP and nadph to add energy to carbon dioxide so we can eventually make sugars um in photosynthesis you make something called G3 P which is a three carbon molecule and then the plant can use that to do other things we can make glucose out of it they use cellular respiration as well so they could get ATP from that or they can use it to build cellulose and to actually build that plant um one other big thing that I I missed here is that electron will eventually go up and get boosted up to eventually make nadph um what's the water used for in photosynthesis it's donating those electrons and those are the electrons that go through what are we making oxygen which is a byproduct of photosynthesis and luckily is a reactant of respiration if we get to DNA and RNA got a lot of questions about that what's the building block it's going to be a nucleotide and here's a nucleotide right down here there are three parts to it you have a phosphate we've got a sugar it'd be deoxy ribos in DNA and ribos in RNA and then you have some kind of a base up above that now if we zoom into this nucleotide right here we could count the carbon atoms so there'd be one 1 2 three carbons four five carbons and so on this side so we're facing up would be the five Prime end of this nucleotide and then on the downside it's going to be the three prime and so how does DNA R run it just runs in opposite direction so it's anti-parallel and so on this side it'd be running from the five to the three and on the other side it'd be running from the five to the three which will become important in just a second what's the other differences between DNA and RNA DNA has got uh deoxy ribo sugar versus a ribo sugar it also has thyine versus uracil we'd find in RNA and then of course a DNA is going to be a double helix and RNA is going to be a single Helix what is the cell cycle the cell cycle is all the steps life goes through or cells go through as they divide and so if we look at a typical cell what's it going to do it's going to during the G1 phase grow and so the cell is going to get bigger what happens during the S phase it's going to copy all of the DNA that it has and so if I have a chromosome one for my mom and a chromosome one for my dad at the end of this S phase you'll see the two chromatids of that we will have copied all of the DNA what happens next it goes into the G2 phase where it continues to grow and then it eventually goes through the M phase what's happening then well that's where it's either doing mitosis if we're making exact copies of the cell or it's doing meiosis if we're making the gamines um after that we divide the cell that's called cytokinesis and then we eventually have two cells now some cells don't keep copying themselves over and over and over again so like muscle or nerve and so they just stay in this g0 phase and so to understand the life of a cell you really have to understand how does the DNA copy itself so that would be during the S phase and then how does it do the job of the cell how does it make RNA and eventually make proteins and control the cell and so let's start with the mitosis and meiosis part so what's the role of mitosis and these would be the phases of mitosis which for AP Bio you don't have to learn or memorize but what's going on mitosis is that we are making sure that we're equally dividing all of the chromosomes inside the cell we want to make sure the DNA goes equally into the two cells or the daughter cells and so the phases what we're seeing is if we can see the chromosomes this would be like beginning of prophase you can see the nucleus breaks apart the chromosomes are now attached to the spindle on either side so right here this would be metaphase you can see them all pulling apart so we've equally pulled off the nuclei to either side now we have two nuclei and then that cell divides into in half and so in mitosis what are you doing we're taking one cell and we're making two cells that are identical when do we do this we do it to replace any cells that are broken and that's how you went from that zygote that first cell to all the trillions of cells inside your body so then when do we ever do meiosis meiosis remember is just the production of the sex cell so this is going to be sperm and egg it looks a little more confusing the importance of that if we look at it starts the same way so we've copied the DNA you can see the two chromatids on either side but the most important things take place right here during prophase one the first one you see is that we've got crossing over occurring and what that is is you're crossing over the chromosomes you get from your mom and your dad and you're giving your Offspring a new chromosome that's a combination of those the other thing that's happening is independent assortment they're randomly lining up in the middle and that's how we get those genetic differences uh in each of the sperm and the Egg and so in meiosis what we have is not one division but we have two divisions and we go from one diploid cell to four haid cells um what does that mean they have half the genetic information of that parent cell and they're going to be totally different from all the other cells as we go back to the S phase and DNA replication what happens in DNA replication in in order for mitosis to work we have to copy all of the DNA before we can equally divide it between the two cells and so how does that work well the big major players would be helic Cas and what that's doing is unzipping the DNA right here so it's breaking it apart we then have add a little bit of RNA that's called a primer and there's an enzyme that does that it's called primase and then we essentially add the new nucleotides on the other side and so if I have a a t on one side of the DNA what's going to be on the other side TTA remember a always goes to T and C always goes to G now something problematic is this I can only add new letters on the three prime end and so on this strand down here DNA polymerase can move to the right as this unzips DNA a polymerase moves to the right and adds new letters on the three prime n that's the leading strand it works great but on the other side we have to keep making these little fragments they're called okazaki fragments and so we're moving away from the fork and then when we're done liaye will attach all of those together and so DNA replication is important because it makes sure that we get an equal amount of DNA the same exact DNA in each of the cells transcription is how we make RNA so this would be taking place in procaryotic cells just in the cell itself but then in eukariotic cells it's in the nucleus and so what are you doing we're copying the DNA into RNA to to do that it's a similar enzyme to DNA polymerase it's called RNA polymerase and what it does is it moves down the DNA and makes a copy of that called messenger RNA what does that do it carries the message of the DNA to the ribosome so we can make proteins and so in Translation what's going on here you can see this is the messenger RNA it's going right through the middle and so what it's what it has are what are called codon on so every three letters of the messenger RNA codes for three letters of the TRNA you can see the TRNA right here it's transferring amino acids so you can see a three-letter match right here and then eventually it delivers its amino acid and then we have a growing polypeptide that's coming out of the top and so how does DNA really control a cell it makes messenger RNA which makes proteins and then it's those proteins enzymes and and the proteins themselves that make up the cell how does an enzyme work an enzyme is also going to be made of proteins and so if we look at a protein itself this enzyme the big parts are the enzyme and then the substrate so the substrate is the chemical that's being broken down by the enzyme or built up by the enzyme so it's 50/50 um as it docks with that enzyme we have what's called uh active uh an active site so let me make this the enzyme if this is the substrate it fits in just like that and then what you have is induced fit where it'll actually grab a hold of it and then it allows it to break break down and so it's the it's the shape that's the most important in that enzyme it allows it to attach to the substrate put a little tug on it lowers the activation energy and then it's able to break it apart how's the immune system work this is another big question it always starts with the macras itself and so if we have something an Invader the first thing that happens is any antigen is going to be swallowed up by a maccrage and we now call that an antigen presenting cell what it does is secrete enzymes from the liome break it up and it's going to present the shape on its surface who's always helping or or waiting rather is going to be helper T what helper T does is sense the shape of that pathogen that Invader again we're only talking about in animals at this point and that helper T cell is going to activate B cells to make antibodies so this part up here the B cells and the antibodies is part of What's called the humoral response that's fighting the pathogens out in the body in the humors of the body or the liquids of the body in the blood blood and the lymph and the interstial fluids and so the antibodies will actually adhere to the pathogen it makes it easy for other ma macras to find it um what else does the helper te activate it activates these killer te cells those killer tees are going to find cells that are already infected and kill the infection there and so this immune system allows us to sense uh a a infection and make sure the next time we're infected by that we've created tons and tons of B memory and killer T cell and so that we can uh fight that response and so the second time you get a cold you don't even know that you had a cold a lot of questions about cell communication an analogy I used in one of my videos is sometimes we need touch if we're communicating between cells so that antigen presenting cell has to touch the helper T cell in Gmail what we're doing is writing from one point to another so in the nervous system you have one neuron and it's not quite touching another neuron and then we'll send neurotransmitters between the two and then a Facebook status update uh if you put an status update out there anybody could read it so that's more like our endocrine system so an endocrine system what you're doing is sending out hormones and the only ones who are interested are going to be the cells that have proteins on their surface we call those the target cells and they have specific receptors for that a real common type of cell communication is signal transduction so an example I talked about in videos is epinephrine docking with a cell in the liver what it's going to do is it's going to release glucose from the glycogen and so we would call epinephrine now a ligend at this surface we call it a water soluble ligend what does that mean it's docking on the surface and it wouldn't be able to move through so if it's a lipid soluble hormone it would move all the way through here but since this one's water soluble it docks on the surface kicks off an alpha subunit it activates a a enzyme which triggers a phosphorilation Cascade what does that mean at each of these steps we're amplifying that message and so you can have one Li docked on the surface and then we can activate the hundreds if not millions and millions of these enzymes on the inside and so a signal transduction pathway is simply a signal up at the top docking with a receptor and then we're sending a message into the cell but again that Lian could have come in and even could get into the center into the nucleus itself and then be turning on transcription factors and turning on genes in the center again feedback loops inside us are going to be mostly negative we have a few positive feedback loops like birth would be an example of that but most of them are negative feedback loops they allow us to maintain homeostasis or keep us at a set point so one of the most famous ones is the blood glucose feedback loop what's going on here the pancreas is either secreting insulin if blood glucose is too high or glucagon if it's too low and so if the blood glucose level is too high insulin is secreted what does that do it allows the liver to take in excess glucose it really is a signal transduction pathway that opens up glut it's taking that in and storing it as glycogen and it's also allowing our cells to take in that glucose signal transduction pathway again what happens if the blood glucose goes too low then we're going to secrete glucagon and that's going to release glucose from the glycogen that was in the liver a lot of GW in there but allows us to keep that blood glucose level at a set point let's say you're type 1 diabetic where's your problem we we have an autoimmune disorder that kills the insulin or the beta produc beta or the beta cells in the pancreas or the insulin producing cells and so you can't secrete insulin so you have to be taking insulin shots and if it's a type 2 diabetic then you have problems in the receptor or in the signal transduction pathway itself a lot of questions about philogyny which is kind of The evolutionary history how do you read these things um if we say here is the Southern and Northern minky whale um this means that they shared a common ancestor at some point back in time and they sh all shared a common ancestor back here and so each time we have a branch Point that's going to be a speciating event where we took one species and divided it in two now it's not like this common ancestor here is these species I mean we share a common ancestor with chimpanzees but we aren't chimpanzees um but uh also you'll see Extinction on here if any of these lines end then it's going to be the end now how do we build these philogenetic trees there's really two pieces of evidence we can use we could use morphological evidence that's going to be using the shape a bone structure for example but the big one is to use molecular evidence so DNA and RNA and so that's kind of a summary of the top 20 questions that I got I I I can't cover everything obviously but I've got videos that comment that will cover almost everything so that might be helpful and so I want to just wish you all of good luck I promised you that I would read out some shoutouts for all of you and so there's quite a few names you could imagine and so I'm going to go through this I'm sure I'll pronounce your name wrong but in Alabama good luck to Kenan in Alaska good luck to Joe and zaquan in Arizona good luck to Dena uh and Lisa and Anthony Catalina and Michael in Arkansas good luck to Lauren and S sarab sorry about the pronunciations in California you could imagine this is going to be a big list good luck to meline Peter Carlos Alvin sadp Reno uh Martin Mai Mr y AP Biology class or y's AP Biology class Josiah Sarah Jason Matthew Abby good luck to paulen Andrew Brian Elvin Darren Bruno Amy Sirin Gia Sammy mlan good luck Hannah Brian Thea or Thea David Roy Sean William Ryan Miss uh arizola's class good luck to you Samantha Dante pray deep uh Michelle Tracy Sunny good luck to Mr Holmes AP Biology class good luck to Tracy Alia Dr Simon's AP Bio students Janie California's AP biology classes Adam Brandon Natalie Jam am Mr Woo AP bio class # gotrio 2014 Judy Brian good luck Master used bioc Class DK Salvador Dr Kira AP bioc class class uh Kona Cameron Tyler Miss ship's AP bio class good luck to Jonathan and Hannah and Mr Gallagher's class and good luck to Matthew good luck California good luck in Colorado to Kayla and Haley and Ben and Hannah and Mrs keigley AP bio class in Connecticut good luck to M Jorgenson's AP bio class Eric Hannah Luke good luck to Hamza Mr kuks AP bio class good luck to Joseph and Michael and aah and haa and Noah and Caro and Zach good luck Connecticut good luck in Delaware to anud deep and Britney in Florida good luck to Lev and Jacob and Briana and Alex and Jonathan and Juan and Madison and Brian and adidi and Tracy and Noah and Michael and Brendan and Greg and good luck to Samantha and Victor and Aaron and Cody and Miss Klein's AP Biology class and Nadia good luck in Georgia to danne and Caleb and julieanne and Matt and Evan and Dr or Miss Ya's AP bio class good luck to Maria Sophia Rosie and Rebecca in Illinois good luck to vatel and Mrs syes syis AP Bio students good luck to IFS AP bio class good luck to Sandy Smith's bio class and Zade and AD and Daniel and Daniel and Miss sex's AP bio class good luck to Haron and Shakib and Abdullah and fer and anest and Cavita good luck in Indiana to South Mount High School AP bioc class in Iowa good luck to Ethan in Kansas good luck to Linda and Nick in Kentucky good luck to Isaac in Maryland good luck to Courtney and Alex and Natalie and Kenny and Toby and Jack and Kylie and Courtney and iin and Jenna and Steph Stephanie and John and salvator and ilon and Christa and Olivia and Britany and Michaela and Samantha good luck to Aaron and sha and Stacy and Nico and Jacob and Kelsey good luck in Massachusetts to homy sunle to Mrs vot's AP Bio classes to Mrs kulu's AP Bio classes to Sid and Mrs me's AP bio class and Mrs Mahone's AP Bio classes in Belmont High School and Mrs liek and doeren Men and Tony and Ashwin and um anat trude and Jeff and Danny and Anton Anton and Jeff and Mara in Michigan good luck to Grace and Rebecca and Ian and Sagar and Osman and Jesse and Andrew and Ray and Jimmy in Minnesota good luck to Andy and Parker and Robbie and Brady and Mrs Hammond's AP bioc class and Haley and Ryan and Logan and Elizabeth and Miss shelds AP bio class good luck in Missouri to Lafayette High School AP bio class and Mrs or 's AP bio class and Lulu in Montana good luck to all my classes Mr Anderson's AP biology classes in Nevada good luck to cila and Jenny and Jorge and in New Hampshire good luck to Brandy and Ariana and Rachel good luck to Mrs Grangers AP Biology class and Mr grimsley's AP Biology class in New Jersey good luck to Eric and anet and anant and Aaron and aushi and Mrs lel's AP bio class and Jamie and Dennis and Rita and Caitlyn and Olivia and vaj and Ali and micro Marth and Anthony and Timothy and Grace and Ryan and puya and sigh and Brian and Cameron and Miss trampler AP Biology class and Samantha and Mrs Clark's AP Biology class and Andre and Alicia and mallerie and Mina and Shay and South Reeve must be South River High School AP Biology class and Laura and Amir and Miss carpy's class and ratan High School AP bio class and Chloe and Kristen in New York good luck to Abby and tenzen and David and Mrs Jasper's uh japser a biology class and Jack and Kim and Allison and John and Danny and zoo and Caitlyn and Ali and nambi and Bobby and good luck to Melissa and Jackie and Miriam and REE and Dominican Academy and Lauren and Davina and Zach and Sarah and Joe and Yad yudas and Mrs Brady's class and Kim and Noah and meet and Muhammad and Alexander and Jorge in North Carolina good luck to Andrew Kelly Ariana and Jerry in Ohio good luck to Ashley and Alexi and Vincent Maya Zachary Chris Karen Chase Cassie and Mrs Mr Boyd's AP Biology class in Oklahoma good luck to Philip and Oregon good luck to Aiden Pennsylvania good luck to Claire and Mary and Miss Williams AP bio class and Tom and Mara and Laura and Liv and M and re and Lil SS and hash ribosomes and Dr wormer AP Biology class and Danielle and Nick and Upper Dublin AP bio class in Rhode Island good luck to Alex in South Dakota look good luck to Mrs rell's AP bioc class and Maddie and Gabe and Lauren and JD Gabe and Derek and Voldemort Voldemort man and good luck to elanie good luck in Tennessee to Sydney and Kristen and manal and Colin and kin and Ben and Mrs Harper's AP bio class in Texas good luck to Mrs Hunt's AP bio class and Rebecca and Cindy and Cartana and Kendra and Anam and sarin and tajes tajes and Kendall and Kamar and prosia and Christopher and Maria and butcher AP bio class in Utah good luck to Jake and Saul and Aaron and Sarah and Mr Lukes AP bio class in Virginia good luck to Mary and Jay and Kosik and DVA and Paige and afron affen and Cameron and Mrs Gallagher's AP Biology class atena and Emily and Miss Gerald and the inquisitive one in Washington good luck to Jack and Alex and Monica and Lewis and uh Louis and Julian and Casey and Mr Anderson and Mrs blocks AP bio class in Wisconsin good luck to Abby and dsha AP bioc class in Megan in Manitoba good luck to Natalie in Albania good luck to clevy and in Australia good luck to Joey and Belgium good luck to Alishka and Brazil good luck to pac's AP bio class and Pedro and in Canada good luck to Aton and Anna and Hannah and yaser in China good luck to Claire and Angela and Miss kegley's keigley AP Biology class in Egypt good luck to Jessica in England good luck to Ava and Ava and Dylan and Joe in India good luck to Bula and Suman and palavi and Anushka in Indonesia good luck to Sandra in Ireland good luck to David in Malta good luck to Shawn in Palestine good luck to Anise in Poland good luck to Veronica Veronica in Republic of Korea good luck to Jay in Russia good luck to Alexander and Rashad and Saudi Arabia good luck to Majid and Samra and Rana and Rema in Singapore good luck to Monica and Jason and Stephanie and Renne in South Korea good luck to Jesse in Sweden good luck to Axel in Taiwan good luck to Annie in Tanzania good luck to sued uh sued and Trinidad good luck to miss OD Donovan's AP Biology class in Uganda good luck to Ronnie and kir and United Kingdom in the UK good luck to danella and Greg in the US people not from specific States good luck to Marty and John and Miss Leek and Tracy and Evan and Annie and Bill and Christi and Ansley and Amiri mea and William and Andrew and kin and NY and Liam and Karina and Alysa and Ryan and donon and Leandra and rajat and Miss bar AP Biology class and then people who just said they're from planet Earth good luck to rashan and the global Concepts AP Biology class hey good luck to everybody I hope you enjoyed the shoutouts I hope the review was helpful good luck on Monday um and uh I probably won't see you again so have a great summer [Music] we