Module 2.6 Flashcards
Mitosis
AA type of cell division wher eone cell splits into two .
-Mitosis is part of a much longer porcess called the cell cycle .
cell cycle
-the whole cell cycle takes a long time
-the duration of the cell cycle depends ont he type of cell (mammalian cell 24 hours)
-Some cells take months
-Some cels even exist the cell cycle either temporarily or permanently .
Cell cycle conists of two main parts
-The Mphase (or mitotic phase ) is when mitosis takes place and cells divide into two .
-However , the Mphse is actuallhy a relatively short period within the whole cell cycle .
Most of the cell cycle is called interphase .
during interphase , the cell ma apper to be relatively inactive , but actually lots of different processes are happening .
-dURING INTERPHSE , THE CELL IS CARRYING OUT THE FUNCTIONS OF THAT PARTICULAR CELL YPE ,.(iNTESTICAL EPITHELIAL CELLS ) - ARE ABSORBING NUTRIENTS from the small intenstine .
the interphase can be divided into three main phases .
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G1 PHASE (1st stage )
-during g1 phase - the cell replicaites organelles such as mitochondria
-Replicating organelles require a great deal of proteins .
-So durinng G1 , a high level of transcrption and translation take place .
(Loooked a in protein synthesis )
.
G1 phase prt two
-During g1 , the size of the cell also increases .
-This ensures that when the cell duvudes , the two daughter ells are the correct size.
second phase of interpahse (second stage )
-SPHASE
Next the cell passes into the s or synthesisi phase .
-During the s phse all of the chromosomes are replicated + to do this , cells need to synthesise a great deal of DNA .
last phase of interphase is the G2 PHASE
now cell enters GN phase .
-During GN , the cellreplaces the energy stores sued during the s phase
-cell contitnues to carry out transcription and transaltion .
-If any of the chromosmes have been damaged , then theya re REPAIRED during gn .
-jUST LIKE g1 PHAE , cells continue to GROW .
Once the cell has fnished G2 phase , it now enters the M or mitotic phase
Mitotic pahse can be divided into two prts .
MITOSIS - chromosomes separate into two sepearae nueclei .
-CYTOKENSISI - cell divideds into TWO .
sometimes , cellcs can exit the cell cycle , if this happeens , then scientists say tht the cell is in the G0 phase .
cell enters g0 phase for three reasons.
reason 1
fully differentiated cells can enter g0 and stay there for the rest of their lives (adult neurones )
reason 2
overtime , DNA can be damaged .
At a certain point , the cell will no longer be bale to divide .
-Scienitsts call this senescent cells , At this stage , the cell enters G0 permanantly.
reason 3
lsdtly , cell enters g0 temporary for example b memory cells
-thee cells an the be triggered to renter the cellc ycle during n inreaction .
-the cell cycle is very tightly regulated .
at certain key points in th cell cycle , the cell chekcs that the cell cycle should continue , Scienitsts call these CHECKPOINTS .
-At any point , if a cell fails a checkpoint , it iwll leave the cell cycle and enter g0.
there are three checkpoints
first checkpoint
first checkpoint
before the spahse ,t he cell must pass thorugh the g1 checkpoint .
-Here the cell checks it has gorwn into the correct size and also checks for DNA damage .
secodn checkpoint
if the cell satisidies the g1 checkpoint , then it passes into the s pashe and carries out DNA repliation .
-Thr next check point is AT THE END OF GN and before cell passes into the mitotic pahse .
-Again at the G2 checkpoint , cell checks for DNA damage and if the cell has grown to the correct size .
third checkpoint
if this checkpoint is passed , then cell enters the mitotic pahse .
-Final checkpoint is called he SPINDLE CHECKPOINT .
-Checks that the chromosmes are assembled correectly on the mtioti spindle .
-If this is the case , then he cellc ompeltes mtiosis and proceeds thorugh cytokenesis .
chromosomes
a cell that is aout to udnergo mitosis
cell only contains two pairs of chrosmomes (just to make diagram more simplfied)
Most organsisms contain lot mroe (23 pirs )
Long chrosmomes are shown in green
and short pair is hsown in ellow
cheomosmoes that are in pairs are xcalled diploid cells .
in cell divisionby mitosis , we staert with one diploid cell and end up with two .
-Two identical diploid cells like this .
-so cell division by mitosis takes place whn we ant idneical copies of cell 9e,g whena n organsism grows and repairs itself )
-Mitosis also used in a sexul reporduction
-mitosis par of the cell cyce.
-cell cycle has 2 pairs m phase nd interphase
-during interpHAW , RHW Cell increases its energy stores and grows in size .
-cell also replicates its organelles nd copies its DNa .
in the miotitic pahse , the cell crries out two processes
nueclues divides into two daughter nueclei (mitosis )
2. cell divides intwo d=two daughter cells each with a nucleus (cytokensis (
-JEY ; mitsosis is specifically refers to the division of thenueclues
division of CELL is cytokenesis .
both cytokensis and mitosis take plce in m phase
CCloser look at key event in itnerphase
KEY ; during interphase , we CANNOT SEE chromosmes in the neucles .
-The chormosmes are there but not visile as DISTINC TSTRUCUTRES .
-Instead we see dark mateiral called CHROMATIN .
-In croamtin , the chormomsoes jage a loose , open strucutre and hti smeans the DNA is ccesile for transcirption dd REPLICTION +TRANSCIRPTION
DNA in a chromosome
KEY ; Dna is a single long moelucl of DN .
KEY ; during interpahse , chormosmoes replictae like this
-now we hve two dienticl moelcule of dna .
-Scienitsts now cllt hese sister chormatids and the chromatids are joined t the centromere .
WHEN DOES THISH HAPPEN ?
KEY ; this happens for every chormsome + in humans that emans 23a[ors .
-This tkes palce during interpahse and the choromsomes sre not VIsible as DISTINCT STRUCUTRES at this stgae .
-After the inerpahse NUCLEUS DIIDES NTO WO DURINGMITOSIS .
cell thzt has just finished interpahse and going to enter mitsois
there are four stages of mitosis
PROPAHSE
METAPHASE
ANAPAHSE
TELEPHASE
Prophase
during propahse , the chromoseomes condesne and beome visible in then ucleus .
-We can see tht each chromosome consits of two sister chromatidss joined at the centrosome .
-The nuecleolus s disappears snd the nuclear Mmembrane starts to break down .
-A pair of centrioles move to either side ( or pole of the cell )
propahse (2)
proteins start to form spindle fbres which attah to the centromere of ach chrosmosme .
-These spindle fibres strt to move the hromosomes towrds the center of the cell .
second stage of mitosis is metaphase
-at metapahse , the spindle apparatus ahs completely formed .
-The chromsomes are lined at the center / equator of the cell .
third stge of mitsooosis - anaphase
-in anapahse , the centrosomes divide into two .
-spindle fibres begin to shoreten .
-This pulls the sister chromarids towards opposite poles of the cell like this .
telepase part two
the chromosmes uncoil back to their chratin -the neucleolus also reperrear in eah nucleus .
-at this point ,t he ell has now finsihednuclear division by mtisoiss nd starts CYTOKENSIS .
foruth pahse is the telephase
in telophase , the chromatidfd hsve reached the poles of the cell .
+now scienitsts refer to thems chromosmes again .
-now the psindle appartus breaks don and the nuclear memebrane reforms .
What happens is cytokenesis
the central memebrne is puled inwrds b t he cytoskeleton .
-this cretes a groove or furroe which gradually deepens .
eventuLLY Tte memebrnes fuse and form two independan ceells .
-cell division by mtisiosiss has finsihed .
THIS P ORCESS IS FOR N ANIMAL CELL .
Variation in plant cells 1
centrioels do not play a role in forming hte psindle apapratus in plant cells .
-as plnt ells do not contain centrioles .
variation in plant cells 2
when plnt cells undergo cytokensis ,t he cell memebrne cannot form a furrow as in animal cells .
-INSTEAD , formt he GOLGI PPARATUS from membrane strcutures down the center of the cell .
-These then fuse together to form the cenral cell memrbane .
-dividing the cytoplasm ino to .
-a new cellulsoe cellw all also forms doen the center .
key
unlike mitosis , cell division by meisosis only takes place in SEX ORGANS .
-that is bevause cell division by meisosis only ever used yto produce GAMETES .
(SPERM AND EGG in animals ) and (pollen and eggs in lanys )
-Iin cell diviosn by meisois , we start wih a diploid cell .
-at the end , we have four
four diploid hetes . (These cells ahve inidvidul chromosomes not pairs )
KEY why IS IT IMPORTAN that gametes are haploid cells ?
-diromg fertilisation , gametes fuse togetehr to porduce a fertilised egg or zygote .
-As gmetes are haploid , the zygote has the diploid number of chromosomes .
KEY ; - all the gametes made by meisois are geeticlly different
esssential ideas aour chromosomes .
-diploid cells chromosomes in humans are in pair s
scientits refrt to a chromosme pair like this is a homologous chromosome , (one rom hpomoglous pair from mternl one homoous pair from paternal ).
key ; both chromosomes in a ioloigicl pair have the exalt sane gene .
-e,g both copeis of chormsome have he same genes
however u can inherit different alleles .
-pallele a from mother
allel from dad
or allele a from andlele from mother and dad
allel b from mum and dad .
-gmetes porduced by meisois re genetically different why ?
homogous pair of chromosomes abt to undergo meisois (mternal and patenral )
-before the nueclues divides by meiosis , all the chromsoomes are copied in the interphase .
REMEBER - sister chromids are joined at the centromes .
-At the early stage of meisois ,t he two chromoesomes in a homoglous serieds com in a pair and
the chromaitds of the two chromsomes wrapp around echother .
-Scientists call this porcess CROSSIN OVER .
-The attached pair of chromsomes are called a BIVALENT .
-Ppoints were chromatids are joined is called chiasmata .
KEY ; parts of the chromtids can BREAKUp AND EXCHANGE BETWEEN THE HOMOLGOUS CHROMOSOMES LIKE THIS . SHOWWN ON PICTURE
-as you can see the maternal and paternal chromosomes hsve now exhaged dn .
-scientits sy this is yhe recombinant CHROMOSOMES .
-AS THESE CHROMOSOMES HAVE EXCHANGED dna . THIS MEANS THEY HAVE EXCHANGED ALLELES .
Looking at blood group chromosome , paternal choromsome on the left is materbal and pterbal choromsome has blue ,
adfter crossing over boh maternal and paternal chromsomes both contian a and b chromosome .
one crhomatid with b aellele other one has a allele . REDO THIS CARRD
bear in midn chiasmata can occcur at multiple points
so a larg number of alleels can e exhanged .
This exhange i alleres is a major source of GEENEIC variation in meisois .
Key about meiosis
Meiosis invovles two rounds of nuclear division .
-in meiosis 1 , homologous chromosomes are separated from eachother.
-in meiosis’s 2 , sister chromatids are separated from
Eachother .
What happens before meiosis ?
-the cell will have been through interphase .
-during interphase , the cell copied the chromosomes and the organelles .
(Remember : chromosomes are not visible as distinct structures during interphase ).
Stage one of meiosis 1
Cell enters neurosis. 1 and the first stage of this is PROPHASE ONE
-during prophase 1 , the chromosomes condense and become visible .
-Homolgpus chromosomes link together forming the chiasmata
REMEMBER
When the homolgpus chromosomes are paired , like this we call this a bivalent.
-at this point , crossing over can take place .Exchanging alleles between the homologous chromosomes .
During prophase (1) part two
The nuclear melegesnd also breaks down .
-the centrioles move to opposite poles of the cell .
-spindle fibres also start to assemble in the spindle apparatus .
Next step - meta phase 1
The pairs of homologous chromosomes are now lined up with the equator of the spindle apparatus
Next is anaphase 1
During anaphase 1 , the spindle fibres shorten .
The homogenised chromosomes , move towards opposite poles .
-for this to happen , the choasmata between the homologous chromosomes break .
Finally , in meiosis 1 , we have telephase 1
In telophase 1 the chromosomes have now reached the poles of the cell .
-At this point , the nuclear membranes reform and the chromosomes uncoil bsck
Into their chromatic state .
At this point cell undergoes cytokinesis dividing into two cells .
-These cells are haploid because they no longer contain pairs of homolgpus chromosomes .
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Meiosis 2 , prophase 2
The chromosomes condense and become visible again .
Again , the nueclear membrane breaks down and spindle fibres begin to develop .
Meiosis’s 2 , metapshe 2
The chromosomes are lined up on the equator of the spindle apparatus .
Meiosis 2 , anaphase. 2
The centromere of each chromosome divides and the spindle fibres shorten
-the chromatic are now pulled towards opposite piles of the cell .
Meiosis 2 , telephase 2
In telephase 2 , the chromatic a HAVD reached the poles of the cell and we now call them chromosomes .
-just like before , the nuclear membranes reform and the chromosomes uncoil back to their chromatin state .
-Finally , each cell undergoes cytokinesis to produce two haploid cells .
Meiosis starts with a diploid cell and produces four haploid cells .
As the chromosome number gables , scientists say that meiosis’s is what ?
Reducfiojal dicison .
Each gamete , made by meisosisnis genetically different to the others we saw .
Crossing over , is a major source of genetic variation in meiosis .
But meisosis increases genetic variation in another way as well .
Shown homologous chromosome pairs lined up on the spindle during metaphase 1 .
(Not showing crossing over to keep things simple)
Key : when homologous chronicles pairs line up on the spindle .
We cannot predict whether the paternal or maternal chromosome will end upon which gamers
Scientists call this independent assortment .
-looking at cell A, the homologous chromosome pairs have lined up so that one paternal and one maternal chromosome are now both on the let and right .
-so when the homologous chromosomes separate , we produce your genetically different cells , shown .
Each cells may have different alleles , depending on whether it contains a paternal or maternal chromosome
Shown in cell two pairs short pair and a long pair , when in reality there is 23 .
How do you workout the number of genetically different gamete’s produced by independent assortment .
2 to the power of the number of homolgpus chromosome pairs .
So in humans just independent assortments is
2 to the power of 23.
So meiosis have two ways to produce genetic variation in the gametes .
1.crossing over
2.independant assortment of chromosomes
One final factor to generic baso adopt
Most organisms produce a vast number of genetically different gametes .
-during fertilisation , both male and female gamete’s fuse randomly with eachotehr . AKAA can’t predict what male gamete’s will fuse with female takegrdn
-This random fusion sofbtakefrs introduces a whole extra level of genetic variation into the offspring .
Meaning of differnetation
process by which stprocess by which stem cells become specialised into different types of cell .em cells become specialised into different types of cell .
Epithelial cells
Cells that continue linining the tissue
The need for specialisation
A multicellular organisms needs to carry out many different tasks at the same time .
E.g to reproduce digest and to protect against diseases .
Teehee is a lot of different tissue for that like digestive , lymphatic and reproductive tissue .
-these tasks require different proteins organelles and feels
Function of erythrocytes
RNSPORT - oxygen tot he cells of the bodty . FUNCTIONS .
ADAPTATIONSS ; dmsll cells ,w hich means they
micrometres ) .
-lavr a large surface area to volume ration ( 7.5 microemtres) Meaning oxuygen can diffuse across their meembranes easily an dreach all the regions inside rhe cell .
-they also ahva e abicnocanve shape increases surface area to voluem rtion . Erythrocytes have a ewell developed cytoskelton –> allowing then to bend . bsed ont he veseel hey are going though allowing hem to squeeze through narrow capillaries .
Neutrophils are much large rhwn erythrocytes
Travel across the world issues of in right uo and entail bacteria or fungi they find there . Neutrophils wre much wronged than erythrocyte disgust they don’t need to whet the smallest capillaries .
Drive to sites if ineffions by loving along the gradient of inflammatory chemical . This so called chemo taxis and wjenisnpossibkebhavsuebneturohiksbhagr receptors for inflammatory chemicals. .
Specialisation of neutrophils - white blood cells
Function - travel to sired kf in function and engulf why bacteria or fungi they find there .
-neutrophils are much larger than erythrocytes because they don’t need to shelter the smallest capillaries .
Travel sites log infection by moving along a gradient inflammatory chemical . This is called chemo taxis
And is possible bevause neutrophils have receptors for inflammatory chemicals .
Neutrophils a multiplier nucleus around one. So it can be more move around more quickly and engulf molecules.
…
Spermatozoa soerm cells —-> specialised for swimming and fertilisation .
They gave a tail undulipodium allows them to swim .
Middle of the tail requires ATP, so sperm have lots of mitochondria. They are also long and then makes them streamlined.
What’s the spam has swamp the excels (over) and digesting on the outside of the Excel. So it can inject the genetic information into the excel so that the egg and sperm genetic information fuses to former zygote.
 the way the sperm breaks through the coating is via an organelle called AER ozone
Type of lysin is called digestive Aunty lysosome.
Once the sperm has digested through the outer layer of the oven, it’s hyper nucleus can enter to form the zygote.
Epithelial cells
Cells that make up the lining between the body and outside .
E.g cells cells that like the alveoli in lungs are epithelial cells .
One type of cell in eooo the liek tissue is the squasmus epithelial cell .
Specialisation / thin and flat r diced diffusion distance of 02 and c02 .
What is ciliated epithelial cells? They have cilia which allow mucus to move along the trachea, and which which is swallowed in the stomach.
Guard cells
In leaf epidermis cells that surround the stomata .
Palisade cells
Closely packed photosynthetic cells within leaves.
Root hair cells:
Epidermal cells of young roots with long hair like projections.
Two Adaptations of palisade cells. Number one.
They are long cylindrical, so that they packed together quite closely, but with a little space between them for air to circulate; carbon dioxide in these spaces diffuse into the cells.
Should they have a large vacuole, so that the chloroplast are positioned nearer to the periphery of the cell, reducing the diffusion distance for carbon dioxide.
Two. Adaptations of palisade cells. Number two.
– They contain many chloroplast – the organise that carry out photosynthesis.
– they contain cytoskeleton, threads and motor proteins to move chloroplast – nearer to the upper surface of the leaf when sunlight intensity is low, but further down when it is high.
Adaptations of Guard cells number one
– Light energy is used to produce ATP.
The ATP actively transports potassium, iron from surrounding epidermal cells into the guard cells, lowering their water essential.
Water now enters the guard cells from neighbouring epidermal cells, by osmosis.
Adaptation of Guard cells number two
– The Godsell swell, but other tips to sell. No cell wall is more flexible and is more rigid where it is thicker. The tip of bulge and the gap in between them the stoma larges.
– As these states are open, air can enter the spaces within the layer of cells beneath the palisade cells.
Cassius exchange can occur, and dioxide would diffuse into the palisade cells. As they use it for photosynthesis, this will then maintain a steep concentration gradient.
– Oxygen produced during photosynthesis can diffuse out of the paralysed cells into the air spaces out through the open stomata .
Root hairstyles, adaptations number one
 the headlight projections quote, increase the service surface absorption of four mineral wines, such as nitrates from the soil into which projects.
– mineral ions are actively transported into the root herself, lowering the water potential within them, and causing water to follow while osmosis, down the water potential gradient.
Root hair cell number two adaptations
Does the root hair cells have special carrier priorities in the plasma membrane in order to actively transport them in ions in.
– The cell will also produce ATP, as this is needed for transport.
CP. 155–156 for more details. Check for the diagram to eat them as well.
Xylem and phloem adaptations
Xylem and phloem from the vascular tissue of plants and I described in topic 2.6.7.
With more information given in chapters 3.3 on transport in plants.
Xylon, vessels and sieve tubes are present in vascular bundles, and then location can be seen in page 156.
Your body has four main types of tissue
Epithelial -lining tissue
Connective tissues - these hold structures tigether sjnfprogifr support (blood bone and Cartilage)
Muscle tissue - made of cells that are specialised to contract and cause movements .
-Nervous tissues - made of cells specialised to conduct electrical impulses .
In depth about epithelial cells
This covers and lines free surface in the borybeufhbwe RHE ekin , activities or the digestive and respiratory systems (guys and airways , blood vessels heart chambers .
Characteristics of epithelial tissue
-epithelial a tissue is made up almost entirely of cells .
-these cells are very close to each other and fork continuous sheets . Adjacent cells are bound together gy lateral contacts such as tight junctions wjdnreemododked .
Characters of epitheliealntiddue
-theee are no blood vessel within epithelial tissue ; cells receive nutrients gy diffusion from tissue fluid in the underlying connective tissue .
-some epithelial cells have short cell cycles and divide up to two or three times a day in I replace worn or related tieeue .
-epithelial tieeue is epdiwlierr to carry out its functions or protection , absorption , fiktirwrik. Exertion and secretion .
What is connective tissue
Connective tissue is widely distributed in the body .
It consists of a non-living extraceullsr matric containing proteins and polysaccharides.
The matrix drowned the living cells within the tissue and enables it withstand forces such as weight .
Blood bone cartilage tendons and ligaments are exwmole of connective tissue even skin .
Cartilage
Immature cells in cartilage is called chord blasts . They can divide by mitosis and sevretd the extra Euler matrix .
-once the matrix has been synthesisers chin fib lasts become mature.
-less active chocdcutes which maintain the matrix -
There are three types of cartilage
Hyaline
Fibrous
Elastic
Hyaline cartilage
Forms the embryonic Skelton - covers the end of long bones in adults voice box all of fat .
Fibrous cartilage
Occurs in the discs between vertebrae in the backbone spine and in the knee joint .
Elastic cartilage
Makes up the outer ear and the epiglottis .
Muscle tissue
Mudslide tissue is well vascularised it’s got lots of blood vessels .
Muscle feels wee called fihredbtheybwrenelinahed and contain special orhennells . Called myofilwmrtnsnwhihfb allow the midflrntossue to contract.
First type of muscles
Skeletal muscles packaged by connective tissue sheets , joined to bones by tendons these muscles when they contract cause bones to love .
Second types odnksicles cardiac
Makes up the walls of the heart and allow the heart to beat and pump blood .
Third type of muscles -smooth muscles
Occurs in the wall of intestine , blood vessel , uterus and uriwntru Tracy’s and it propels substances along these Tracy’s .
What is Meristem
Area of unspecialised cells within a plant that can divide and differentiate into other cell types .
Organ
A collection of tissues eorking togeyher to form a function related functions
Phloem
Tissue rhat carries prodcuts of ohtoshntheiss , in solution within plants z
Xylem
Reissues fhat carries water and mineral ions from the roots to all parts follow the plant
Epidermal tissue
(Like epithelial tissue in snails )
-it consists of flattened cells that , apart from the guard cells lack chloroplasts and form a protective covering over leaves teaks and roots .
-some epidermal cells Wlso have walls impregnated with a waxy substance forming a cuticle .
Vascular tissue
Vascular tissue is concerned with transport (xyleknajdnojloem )
Xylem vessels carry water and minerals from roots to all parts of the pelts .
-phloem ehehe tuband e trwjerer the products of pjtosystnehsir (mainly sucrose ) in solution , from leaves to parts of the plant that do not pjtosytnehsis such as roots toriwnt shoots .
Merisremrwirc tiesue
Corn wine tell cells and rrrribrrbhybcell differentiation .
Fellenijnkeriereme have thin walls containing little cellulose and no chloroplasts
Do not have a large vacuole
Can divide by mitosis and differentiate into other types of cells
Some cambium cells differentiate into xylem vessels
-lighting (woodu subsyjce ) deposited into cell walls to reinforce and warerporofntjem but this also kills the cell .
-the ends of the cell break down so that xylem forms continuous volume with wide linens to carry water and dissolved minerals .
Other cambium cells differentiate into phloem siege tubes or companion cells .
-sieve tubes lose most of their organelle and sieve plated develop between them .
-companion cells retain their organelle and continue metabolic functions to provide atp for active loading of sugars into the sieve tubes .
Main functions of leaf
Photosynthesis
Main function of root s
Anchorage jn soil .
-ahsorotion of mineral ions and water .
Storage like carrot parsnip store carbs
Main function of stem
-support
-hood leaves up so that they are exposed to kore sunlight .
- transportation of water and minerals .
-transportation of products of photos Yh rose .
- storage of products of phtosytnehsis liek pottu tubers etorebeterch
Function of fower
Sexual reproduction
Digestive systems
Oesophagi stomach gland liver pancreas
LIFE PRODCESSSES CARRIED OUT :but nutrion provide ATP and materials for growth and repair .
Circulatory system
Heart and blood vessels
Examples of life processes / ransport to and from cells
Respiratory dryers
Airways and lungs , plus diaphragm and intercostal muscles .
-breathing and gaseous exchange extewriin .
Urinary dryer
Kidney uttered snd bladders
Example of life processes exertion
Integumentary system
Skin hair nails
Example of processes : wagerloofing , protection , temperature regulation .
Musculoskeletal Sket so shfem
Skeleton and skeletal muscles
Life processes , support lortecfion and movement .
Immune system / bone marrow thymus gland
Examples of life ldocessss protection against pathogens
Nervous system
Brain spinal cord and nerves
Life processes / communication , control and coordination
Endocrine system
Gland fhat make hromones - thyroid , ovaries teddies and adrenals
Life processes / communication control and coordination
Reproductive system
Organs tissue penis ovaries uterus
Life processes repdociok
Lump system
Lump jfoss and vessels
Life processes - transport full jud bsck fkr he circulatory systems and is also improtant in reisditing infections
Stem cells
On differentiated cells, capable of becoming any type of sewing, the organism are described are described as pluripotent .
-are able to express all their genes .
-can divide by mitosis, and provide more cells that can differentiate into specialised cells, for growth and tissue repair.
Sources of stem cells (one)
Embryonic stem cells – these are present in an embryo formed when the zygote begins defied.
Stem cells and umbilical cord blood.
Stem cells sources, part two
Adult stem cells (also fun, children) I found in developed to choose such as the blood brain muscle bone adipose tissue.
They act like a repair system because they are renewing source of undifferentiated cells.
Induced pluripotejy cells developed in laboratories by reprogramming different different cells to switch on certain key and become undifferentiated.
Potential uses in research and medicine
Bone marrow transplants stem cells from burn barrow are already extensively used in bone marrow class to treat diseases like leukaemia and diseases of the immune system. They also used to restore the patient’s blood system after treatment for cancer.
Drug research
Stem cells can be made to develop into particular types of human tissue, the new drawers can be tested first on these tissues rather then animal tissue.p
Developmental, inter biology
Scientist your system in many ways to research developmental biology.
They can study how these cells develop to make critique the cell type and then eat self function so they can see what goes wrong when they are disease.
They are trying to find out if
Because of damaged tissues or replacements, lost tissues
Is difficult to culture themselve they s in the lab. Also their cert to find out which side to use self in molecule needed to direct the different stem cell.
– Have been used to treat my type one diabetes by programming to become pagetic. Research is underway to develop such treatment for humans.
Repair of damaged tissue part two
Morris themselves can be used to put into liver cells liver.
Stem cells can be used after Alzheimer’s or past final.
Can be used to populate or buy scaffold of an organ and then develop and grow specific organs. This is called regenerative medicine. The patient tells her obtained and then you can reprogram up my cells and then they can make the organ so that we no need for immune suppressant drugs.
Samples may be used to preconditions arthritis strokes. stem cells may eentually be used to treat anyc onditions inclduign arthiris sorkes burns visiosn and hering loss .
