Campbell Biology 12th ed Chapter 1Lecture Part 1

[Music] hello everyone and welcome to pocket size bio with Dr CCO this video begins a

series of lectures with uh Campbell Biology right and Campbell Biology is a gold standard if I can say textbook that many undergraduate students use or AP

biology students use and I have yet to see full lectures of individual chapters on YouTube so I wanted to kind of tackle this uh Endeavor here so today we're

going to talk about chapter one and I do want to note that uh my videos are pretty much showing notes that Encompass every chapter all the uh all the content

of every chapter and the visuals right so you can see what I'm discussing and so forth I Prim use this blue one you

see here the Campbell Biology but if you're using biology a global approach that is also fine there's some Er

discrepancies between the chapter allocations But ultimately it's if I can say identical content right so anywhere

where that occurs I will uh let you guys know okay just a little bit about myself guys and kind of um what what I'm H

doing so my name is Roman CCO I'm a PhD holder in um cell biology and I focus my studies on regenerative

physiology right and uh I do uh academic mentorship to undergraduate students and high schoolers right so they can publish their work in high school journals or attend

conferences so far all my students that I have mentored have had a 100% success rate and if you need some mentorship I

can provide uh one-on-one um lessons for you right if you want to start a research project from zero or if you need help you already started something and you need help on uh certain

experiments or data analysis or writing the Manu manuscript I can help you with that right so you can book a lesson with me on preply or preply um and the link

is in the description all right enough about me guys let's get started with the chapter okay so uh we begin Campbell Biology of course from the beginning

unit one Evolution and uh the themes of biology and scientific inquiry right so the key Concepts we're going to talk about is just characteristics of life

certain core themes that Encompass biology which is evolution right and a little bit of the nature of science uh which is is encompassed in the

scientific method okay so this is a nice little depiction here that kind of gives you a scope of what we're going to talk about right figure 1.1 it says the light Appel color of

this beach Mouse allows it to blend into its habitat brilliant white sand dunes dotted with sparse uh clumps of Beach Grass along the Florida Seashore mice of the same species that inhabit nearby

Inland areas are much darker blending with the soil and vegetation where they live right so we're going to focus on this

idea of um biology and the themes that Encompass biology Evolution how we have certain levels of organization in our body and even as we get into a broader

scope of biology right we have ecosystems and communities and populations um how everything is kind of organized aside from that we dive into

the organism and how an individual organism works and terms of genetic information and gene expression and how uh matter and energy

cycle between the non-living uh components of Earth and of course the biotic aspect of earth right living

organisms okay so get into section 1.1 that I'm going to kind of break it down into so section

one or concept one the study of Life reveals right unifying themes okay it's

a little difficult to fully um answer right what is life it's a very simple question but it's can be broken down

into fairly complex um Parts oh sorry okay we could recognize some key features about you know what defines us

as living organisms and sets us apart from rocks or soil so to say okay so uh it is enormous in scope right the whole

study of biology is the scientific study of life and it is broken down into several Concepts or themes right organization information processing

energy and and matter interactions between living organisms and um other living organisms and non-living things and evolution

here here you can see some examples of the properties of life we're going to get into also okay living organisms they tend to exhibit

order right they tend to show a change over time where they adapt to their environment evolutionary adaptation regulation where uh organisms are able

to cope with their environment under changing conditions right uh energy processing one way or another we all must have

energy within our body or else we will die right um growth and development all organisms from the

moment that they're formed that they're uh given birth to right they need to um produce new features grow in size so

they can survive and thrive in their environment without um that being said we can't just be in an environment we also need to respond to the things

inside our environment right so response to the environment is very critical and of course although it's not critical to have as a property of life we do need to

reproduce or else our whole species will disappear right we're not infinite we don't have an infinite lifespan um we're born we grow we reproduce we

die right but we need to continue knew the species uh so this is a feature of life okay so the first them the First theme

we're going to tackle is new properties emerge at Su uh at successive levels levels of biological organization okay so uh the study of

life you know it um we have different um scales if I can say right we have the microscopic

scale sorry can I have a little typo here right can extend from different scales of organization we have the microscopic where you're talking about the individual organism and going inside

the organism and um even talking about individual cells going even further with uh macromolecules right

uh to the macroscopic from the individual you go further to the population many individuals right Human Society as an example getting into where

we live the the community of other living organisms to a whole ecosystem to the entire planet even the biosphere so more in detail this is an example of what I'm talking about right

this panel here you have the broadest scope which is the biosphere it encompasses all e um ecosystems around the world and and so forth right then if you zoom

into a particular location get a little bit more defined you have an ecosystem very specific abiotic factors right temperature uh the overall

climate um the type of organisms that are living within that particular area into a community communities are basically referring to only living

organisms right here you see a picture of certain deer and plant species okay within a specific area then you get into

populations right just one specific kind of species all right could be just a species of deer species of um rabbits or

rodents Etc okay into that individual organism the plant we're getting more and more specific

okay within that organism we get further down that individual organism then turns you break down that organism into several of its parts basically the

organs we're all familiar with this right um You have your heart you have your stomach etc etc uh of course there's some more refinement that needs

to be shown here the organ systems right but uh we get into that later on in the chapters so for organs get into the tissues several tissues or several uh

several uh cells similar cells working together to create an overall function okay here you have an example

of a leaf several tissues within the uh Leaf several cells within the leaf to um create an overall process of photosynthesis you zoom in more into

that you have your cells okay you have a plant cell within that plant cell you have organel right you have the nuclei you have the mitochondria you have the chloroplast here you can see an example

of an organal which is the chloroplast and further down you have a particular molecule okay in this case you have chlorophyll

molecule every single um scale you know has some certain characteristics that execute a function when they work in concert with

other or um um structures they can create a a new property right that we're going to take a look at in the next

thing okay oh sorry let me go down a little bit so this is what I was referring to in uh in terms of properties they're

referred to as emergent properties right and these are properties that come about due to interaction or arrangement of particular Parts structures and then as

you have this interaction complexity tends to increase right you have chloroplast producing you know uh or carrying out the process of photosynthesis is right but the

chloroplast in itself that organel requires many different proteins it requires chlorophyll to absorb light to to even start off that process right so

you have to have several components and you to you need to have an interaction between these components right or coordination if not you're just going to have a mix of many things but um

nothing's really happening right so when you have that coordination occurring then you get an emergent property okay and then so that idea of

emergent properties and and kind of getting different components and putting them together is is um in a nutshell called systems biology right you're

exploring biological systems by analyzing interactions between you know whatever Parts you're focusing on okay it could be a single leaf it could be a

whole organism like a frog it could be a colony of ants right what's their behavior their individual behavior and then as a whole right it could be an entire ecosystem so it's a it's a broad

concept but it hits it defines the point of emerging properties okay um within a systems biology we're going to focus on um

Dynamic behaviors right and dynamic behaviors tends to open up more questions all right um molecular interactions or or your

whole metabolic um Machinery how does it influence the sleep cycle of a person and how can you alter that sleep cycle

so there many scales you can um kind of discuss or research right carbon dioxide levels affect biosphere and alter um

ecosystems right uh to what degree can they affect you know the individual or particulars of an ecosystem and so forth all

right okay so talking about structure and function so these are some of the properties I was mentioning in terms of properties of life

okay so structure and function a very very important principle you're going to see this many times throughout the year throughout the whole context of the book that the way something is structured

will kind of Define the way that it works right and in a simple example you have the flat shape of leaves right we've all seen how leaves are we've

experienced them since we're kids we interacted with them they're structures that are incredibly flat of course there are exceptions with adaptations and things like that but just your standard

leaves and the reason why it's flat is to maximize surface area exposure that you can have for sunlight right so you can produce photosynthesis more

photosynthesis more glucose production more energy for the organism okay so analyzing biological structure can give a clue as as to what it does and how it

actually functions how it works uh the wing of a hummingbird the the the anatomical structure of a hummingbird is quite unique that it

enables Wing rotation within the the the structure right so this gives the hummingbird a higher degree of rotation of freedom of mve movement in comparison

to other birds okay so this is an example of what I mean by structure and function we're going to see this in a lot more detail in the the later

sections all right one of the main main Key properties of life is the cell okay so an organism's basic unit of structure

in function and function so this is what kind of defines if I can say um life right so cells are are the smallest unit of

organization that can perform all activities required for life we're going to see cells all throughout this a

uh electron uh microscope uh image of a cell there's two types of cells you see here here's an El carotic cell you can think about of as an animal cell for now

and here you see a little bacterial cell procaryotic cell um with their adequate size comparison very very small compared to anotic

cell okay so this idea that cells you know are are the the the the necessity the necessary structure for

life right comes about by this idea of the cell theory first developed in the 1800s you know based on many many observations from scientists you know trying to figure out what we're made up

of and one of the components of this cell theory is that all living organisms are made up of cells and the cell is a

basic unit of life okay and again this is a a theory which I don't want to just brush it off as we're going to see later

on in this chapter theories have a substantial amount of evidence to support this generalization okay uh so don't take it

this idea lightly most likely if you find an organism or some some some entity that resembles a living organism most likely they're

going to have cells okay but um there's so many different types of cells all right approximately 200 uh different types of cells within um

humans but they share certain characteristics amongst all of them okay one of them is a membrane okay so if you see here you have these

structures here that uh you have these cells that have a bunch of things inside of it but how do you keep it sorry uh how do you keep it all within this

structure right you have to have some type of boundary some type of border so this is what the membrane is right the membrane regulates materials coming

in uh material leaving the cell and just keeps everything packed Within this structure and there are two types of cells that I kind of mentioned

beforehand right procaryotic cells and they belong to uh the groups of bacteria uh sorry bacteria and ARA belong to this group and they're pretty much single celled organisms means that they only

consist of one little cell and you have El carotic cells much more complex much bigger as we're going to see later on and these could be single celled

organisms or multicellular organisms composed of different cells right or or multiple uh cells eotic cells like I mentioned um as

I'm mentioning right they contain membrane enclosed organel we're going to see this in a little bit uh they contain DNA which is housed within a very

special organel called the nuclei the nucleus okay and you can see this the nuclear structure here and DNA is found

within um many types of organel these small little structures that you see these globular little structures are organel okay and many of them have their

own membrane an example of uh organel is chloroplast you also have uh the endoplasmic reticulum mitochondria many many more that we're

going to describe and El carotic cells are generally larger than procaryotic cells as you see here in this

micrograph okay let's continue all right going to next theme

there life processes involve the expression and transmission of genetic information right so this is another key

element of Life the idea of um having genetic information right having DNA expressing the information that's contained in that DNA to produce a

protein to make the organism function properly and of course you want to pass down this information from parent to offspring parent to

offspring okay but I'm kind of getting ahead of myself let's get into a little bit of the um Essentials right so what

is this information this this uh the structure of information that we I keep talking about right uh essentially it's DNA okay structures known as chromosomes

they connect they contain genetic material in the form of deoxyribonucleic acid commonly known as DNA we all have

heard of DNA we all can get a sense of what it is right and the idea of DNA right it it's the control center of the cell it contains that information to

create protein right but other than that it's also uh necessary to copy this information pass it down from one cell

to another as it divides right the idea of cell dividing is referred to as mitosis and cell division and when that occurs the DNA needs to copy itself

right it under goes several processes of condensation it condenses into these rodlike structures right so you can equally divide the cell and the same

amount of DNA to two new cells right here's a a um a colored micrograph a stained uh micrograph of a cell that has

its copy of DNA right and they've condensed into chromosomes and it's under it's undergoing cell division right here it seems to be in an anaphase

and then it's passing through and splitting into two new cells basically you have a telophase occurring here and what I want you to see is that in blue

is indicated by DNA right the the the DNA is indicated in blue each new cell that's about to form will have its own copy of DNA again we're going to see this

process in a lot more detail step by step later later on okay so uh talking a little bit about DNA more in detail um yes it is the

genetic information okay sorry about the noise outside okay sorry about the noise outside um yes DNA the genetic material right so a

a chromosome so I talked about uh chromosome before right it's basically it's a long strand of DNA that could vary depending on the species on how

much information it's carrying but it can carry a 100 to a thousand um different types of genes right and a gene is just a particular section of

DNA and a gene encodes a information to create a protein to build a protein and depending on how you use these genes how you turn on some genes

or you leave off some other genes it gives a cell a certain identity right that's how we can kind of distinguish and develop different types of

cells all right so when we um are first conceived right when you have an Exel in a sperm cell undergoing fertilization

here you have your fertilized egg you have a new individual right it starts as one cell but it contains all the genetic information in that one cell as as the

cell divides and divides and divides right different cells are starting to have a a kind of an orchestra of different genes turning off

and on for certain periods of time to turn into and develop into that individual in this case you have this little baby here human baby okay oh my

goodness all right so yes as the cell is being um as is fertilized and you produce its new individual the cell needs to copy itself

uh sorry the DNA needs to copy itself the cell divides as the cell is dividing and dividing and dividing DNA is copying and copying and copying right so every

new cell has its own set of DNA okay so I've been talking about DNA here and DNA there what is uh how does DNA actually look like like and what is it

composed of right so going a little bit um lower here the molecular structure of DNA accounts for its ability to store information right remember structure

fits function right so DNA is made up of two long chains each individual chain looks something like this okay and there are essentially two

chains that are interacting together and they're coiled up into a helix so you can see this little Blue Area here right the backbone of the the sugar phosphate

backbone uh where two strands are entangled within each other amongst each other okay so you have these strands or

chains they're arranged in a double helix and what makes a a strand a chain is essentially four types of building blocks that are repeating in a

particular order all right they're abbreviated ATC and and they stand for adenine thyine cyto and guanine you can see them here this

little diagram representation here this is a a nucleotide right each of these four

letters are referred to as nucleotides and a specific sequence of nucleotides provides information to

create a specific uh protein right or specific amino acid that we're going to see later on okay so sequence is incredibly

important in genetics right in gene expression this is one key thing you need to always remember right the specific sequence of a nucleotide will

determine the information that is being carried ultimately creating a specific amino acid or polypeptide which will

produce a specific protein okay just to give a little analogy here you have rat rat rat is one word tar is is another

word art is another word a different word right they they mean different things so similarly to that the DNA has

the same kind of um uh process right where these four different types of building blocks these

nucleotides right they're arranged differently so they produce something new definitely we see this in a lot more detail as we go

along okay so continuing on with the concept of genes and proteins and gene expression right um so like I mentioned

before right genes that are protein in coding right they control protein production right because they have that information to produce that

protein a related molecule right for DNA to kind of help with the protein production is referred to as RNA and it serves as an intermediate

molecule to carry out information okay so if you want to produce a protein you undergo this particular process from DNA like we saw

the little molecule you have a process called transcription which creates a RNA molecule that RNA molecule serves as a

kind of temporary blueprint which um under go a process called translation where you have a protein a

protein using that information to manufacture um a the protein is going to be manufactured right in a particular sequence

there that overall process of getting information passing it from DNA all the way to um basically the factory which is

a ribosome is referred to as gene expression okay gene expression here you can see a uh a breakdown a visual breakdown of what's

happening right in our in our in the nucleus we have DNA there's a specific sequence of DNA it creates an intermediate molecule called RNA this

process is called transcription transcription holds the information to produce protein this is called translation and

proteins have a different building block called amino acids right and ultimately you have the sequence of amino acids to

produce a protein that has now kind of it it creates its overall structure ultimately to produce its function in this case the book gives an example of

crystallin right uh crystallin is a transparent protein that is used inside the formation of the lens

okay uh which is of course fundamental for our eyeball okay so um it's okay if you don't

understand uh everything completely right now so this is just a very broad overview of genetics right and gene

expression okay different organisms this is something quite interesting right that different organisms they employ essentially the same genetic code that same

process sequence of nucleotides will produce a protein okay many many many species around um within this living

world right difference between organisms reflect different reflect differences between DNA sequences yes you different species have different sequences of DNA

but nevertheless the process in which you go from DNA to protein is relatively similar so this brings me to one of the

main um um themes of biology the universality of the genetic code is a strong piece of evidence right that all

life is related and we are all related to each other in one way or another because of the simple fact that we use the same process right

so um going into a little bit of detail with RNA an RNA molecule right RNA

molecules they um especially in recent uh times and in research right um RNA is a singl stranded nucleic acid right and

it serves as a component of a organal called the ribosome and that's where the Machinery to create the protein occurs right or or uh is

located right so it serves as a component for cellular ma Machinery but RNA can also regulate a gene um encoding

for a protein right so it has regulatory functions and it has structural functions right very very critical for gene

expression so getting a little bit aside uh genomics studying we've been talking about the idea of DNA sequencing

sequence turning into U RNA to produce a protein the study of all the DNA in your body right and and with the use of

computational biology is essentially called genomics right where scientists have developed incredibly large

libraries of genes right um and to analyze okay all the genes in our body is referred to as the genome and that analysis of the genome is referred to as

genomics okay so scientists have accomplished and have sequenced many organisms including

humans so imagine imagine if you knew all the genes in your body and you know how they work right then we can um uh

have more insight to Medical applications right biotechnology and so forth so uh genes sequence is essentially the genome sequence is the

entire sequence of nucleotides in an in an individual species okay as I mentioned before genomics studies the whole set of genes in one or more

species and related to that proteomics proteomics studies um all the sets of proteins and the sequence of their proteins and their properties right in

an individual and uh as we as we go along in the book and we see different types of uh methods

and techniques right the scientists have discovered over time and have implemented over time uh it's much easier to do Gene analysis but um one of

the biggest right um reasons why gene analysis has been able to come about is because of sequencing right and nowadays we have

high throughput sequencing where you can sequence using a using a a um a machine you can actually determine the exact

letter sequence of a particular DNA uh sample and you can analyze that DNA sample via the study of um uh the

implementation of computational tools to manage large sequence data that is called bioinformatics right and ultimately you need to kind of figure out what is the

meaning of all this sequence right and that does require a lot of collaboration between mathematicians biologists com um

um um computational biologists right to have some overall understanding of what it is you want to study and analyze

okay so next theme uh life requires the transfer and transformation of energy and matter right this is a very familiar topic to most of us that we we've we've

seen in high school right so energy and matter right every activity we do in this life requires energy energy is the ability to do work we need to get energy

right throughout our day one way or another ultimately the energy input that comes into these living systems in this

world comes from the sun the majority the majority okay and um it is it it is

transformed right into usable forms right so we know plants producers autot trops right these are organisms

that can harness the energy of the Sun and you get from light energy and you convert it into chemical energy

right and sugars glucose primarily so although humans right animals can directly produce glucose

with light right but we consume organisms that do do that right light light energy is produced into chemical energy and then food and that form of

energy is passed on to Consumers basically us heterotrophs okay so you see this nice representation we all it all starts from

light energy coming from the sun energy is flowing into this plant this autot and this autotop harnesses that energy produces glucose some uh consumer like

this worm here eats that plant always if I can say in every um Step uh within this flow of energy

you're going to have heat being lost in the system okay one way or another so consumers of course we need

energy to do work we always lose heat as we burn and consume energy whoops so one of the important things about

this energy Flows In One Direction you always start from the Sun you have that highest um input of energy as it's passing

through different organisms you're going to have um energy decreasing more energy is lost as heat you'll never see energy

going backwards right it always goes in one directions chemicals and matter though do cycle they can go in different

ways in different directions okay um and when I mean chemicals I'm talking about oxygen carbon dioxide nitrates

right organic matter um just as the the organism here you have this little worm that is feeding off the plant the worm could die into the soil breaks down um

by this uh decomposers remaining material could go into the soil serve as nutrients um into the soil

for the plant so you have a cycling of chemicals right um going in different directions but energy only Flows In One Direction

okay okay another theme next theme so from molecules to ecosystems interactions are important in biological systems so as I

mentioned before there's a level of hierarchy right where you have this idea of interactions right between components it's critical you have to have some

interactions because how are you going to know if you know you are able to react to to Something in the environment

right you have to have interactions and and um some examples of this interactions and responses right could be regulation of

blood sugar levels right body body cells must be having um the the a necessary level of sugar right

for their for what the work the the the the work that they're doing inside the cells right so the body has to be regulating sugar concentrations if your

sugar levels too low you need a way to bring it back up and so forth right so the ability to kind of

regulate biological processes is referred to as feedback a feedback mechanism sorry and there's different types of feedback

mechanisms okay but in a nutshell a feedback regulation or these mechanisms is it's an output right um a

yeah the the output of a certain process will regulate that very process it's a little confusing but we'll take a look at it the most common one that we think

about is negative feedback regulation where you essentially have a loop right where the response to a particular

stimulus reduces the stimulus okay insulin signaling after a meal right and here you you have this

example very nice example here so you have number one high blood glucose level stimulates cells in the pancreas so let's say you just you just had food right you just had food you have a a

surge of of glucose there's a lot of glucose in the blood okay high blood glucose level stimulates cells in the pancreas to secrete insulin insulin

circulates throughout the body insulin binds to body cells and that tells them hey we need to consume we need to collect some uh glucose and start uh

either burning them or putting them in a storage mode form right called glycogen and that will lower

the um the glucose concentration right that lowered glucose concentration does not stimulate insulin production because

there's not that much okay so um insulin will help ra regulate its own stimulus right negative feedback

mechanisms okay then do you have another form called positive feedback regulation uh here positive feedback means that it kind of reinforces so the end product

that you're making will speed up even more production okay so one common example is clotting of your blood in response to

injury right uh if you get an injury you get a cut right this will kind of um um trigger a reaction right an inflamatory

response for blood clots platelets to come and aggregate aggregate right platelets are particular um structures that can help and and and seal right a

wound but as they're sealing and they're coming they release more chemicals to attract more platelets right so you need a different mechanism to to to stop that from

happening because you don't want to over clot that could lead to a problem of course in in a normal situation uh we do tend to regulate it well okay until this

the the the wound is sealed right adequately okay feedback regulation we're going to see many more examples later on

okay you see this form of uh interactions of Fe backs um even on ecosystems right so uh an an ecosystem

right just to kind of clarify there is an organism's interaction with other organisms and the physical environment at an ecosystem level organisms they're constantly

interacting right very very interesting here how you have in this example you have an acacia tree right you have this um

uh you have this organism here you have the aasia tree you have soil microorganisms insects that um actually

can live within the acacia tree right particularly ants there's some species of ants that can live within the tree and some of these Acasia trees have

little kind of spikes that if an if um a predator comes in and and hurts the tree the ants can come out and attack and defend it itself

right so you have these nice interactions right occurring Within These organisms there are many types of interactions uh we won't go into many

detail in a lot of detail with um of all of them but just to name a few there's mutualistic um interactions where you can have both organisms benefiting from each

other you can have a parasitic type of relationship where uh one organism host is um harmed while the parasite is

getting benefited right you have commensalism where one organism uh gets benefited and the other one doesn't like Wells and

Barnacles competition right uh between plants and let say certain nutrients in the soil okay so organisms are all are in

constant interaction with the environment okay even uh with a abiotic parameters like sunlight carbon dioxide and oxygen we're going to see this later on where

you have this cycling of material right uh plants they they uh absorb sunlight and they also bring in carbon dioxide

inside the leaves photosynthesis to occur and as an output you have oxygen okay uh and so forth uh one thing is interesting about

environments is that they're they're not um fixed right environments are dynamic they change right they also the organisms they um impact on how the

environment changes right plant roots they can break down rocks par fish they come and and create sediment because they nibble um they Grain on Coral right

so they create a refined sediment right plants and producers they're they're providing oxygen to the environment right so uh

environments are are Dynamic right they're fluid they can change based on the behavior of organisms

okay so the last part that I want to talk about for concept number one right human interaction has greatly affected the environment and this is a big big

problem there's a whole um unit based on human impact right in the past 150 years there's a great increase in um the

burning of fossil fuels right we all know fossil fuels consist of coal oil gas all the things we kind of use in our daily lives right there's a net increase

in carbon dioxide output right there's an increase in the amount of heat that is trapped in the environment right and unfortunately there's a net increase in

the average temperature of the planet right climate change and global warming um and so forth right so this is yeah this is one of the biggest things

about climate change that there's been a a directional change in the overall uh temperature right of

the of the Earth right so of course that in itself brings a lot of um um changes in in and and patterns of climate you

have a lot of more winds precipitation P patterns fluctuate um the frequency of extreme weather if if some of you probably know

there's more intense fires right around I want say around all the world but in certain locations like California and

Australia right so that gives a uh big impact on uh living organisms right many living organisms get affected right this

little table that I uh plotted here organisms affected you have polar uh polar bears of course um Gravely

affected by climate change they it the the these ice platforms right are melting so uh how are they going to

thrive if there's no area to kind of thrive in right so there's food short shortages if you don't have these platforms to

how are you going to get food right so that's increasing the mortality rates in polar bears okay there could be a point where

you're having so much loss of habitat of the environment organisms can't move fast enough to migrate so what happens population size decreases or to the point of

Extinction right so very very important to to to know this idea of human interaction of human

impact right so this finishes section one uh concept one of uh chapter one take a look at these questions here and

I'll see you guys in the next video for chapter uh one is section two thank you guys

[Music]