day 8 september 19 chapter 5 scribd

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Day 8 - Chapter 5

September 19th You know what to expect with YoutubeAssignments now- Please make sure they are complete-




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How do genes work? An o ve r v iew

Just as having a recipe for chocolate chip cookies is not the same

thing as having the actual cookies

Think about it: every cell contains all of the informationneeded to manufacture every protein in the body.

This means that the skin cells on your arm contain thegenes for producing liver cells and red blood cells andmuscle tissue—but they don’t.



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q Genotype• all of the genes contained in an

organism

q Phenotype•

the physical manifestations of theinstructions



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5.6 Transcription: readingthe information coded in DNA



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5.7 Translation: using informat ionfrom DNA to build usable molecules



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Several ingredients must be present inthe cytoplasm for translation to occur.

q Free amino acids

q Ribosomal units

q Transfer RNA



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Causes and effects of

mutationq Alteration of the sequence of bases in

DNA

• can lead to changes in the structure andfunction of the proteins produced

• can have a range of effects



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Mutations

q Bad reputation

q Tend to be disruptive

q Very, very rare



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Almost everyone in the U.S.consumes genetically modified foods

regularly without knowing it. W ha t f oods a r e r e spons i b l e f o r th i s ?



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Insect Resistance



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How can genetically modifiedplants lead to reduced pesticideuse by farmers?

1961, the toxic “Bt” crystals were included inpesticides

1995, however, recombinant DNA technology let to DNA thatincluded Bt



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Herbicide Resistance



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Faster Growth and Bigger Bodies



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5.16 Fears and risks: the safetyof genetically modified foods



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q Fear #1. Organisms that we want to kill may

become invincible.q Fear #2. Organisms that we don’t want to kill may

be killed inadvertently.

q

Fear #3. Genetically modified crops are not testedor re ulated ade uatel .



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(1) M app ing Gene t ic L ands capes : The Human Genome Project

the three billion nucleotide base pairs in the

human genomeand to identify all the genes present in it, 2000



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(2) Building Earth’s Family Tree

phylogenetictrees were builtbased on

similarities inorganisms’physical structuresand embryologicaldevelopment, DNAsequences



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When we say humans andchimps are genetically 96%

identical, what do we mean?



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5.19 The promise and

perils of cloningF rom o rg ans t o i nd i v idua l s



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1997IanWilmut,

aBritishscientis

t, firstclonedasheep

surprisingly simple

inconcept



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Are there any medical

justif ications for cloning?

Cloned animals might produce human medicinesor organs



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Is it possibleto clone adinosaur? How

could it bedone?



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A chicken dinosaur?Scientists discoverwhat the bird mighthave look liked inprehistoric times




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cells



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6.1 Immortal cells can spell

trouble: cell division insickness and health.

Once you are fully grown, do you have just oneset of cellsthat live as long as you do?



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Telomeres

q

The telomere is like aprotective cap at theend of the DNA.

q Every time a celldivides, the telomeregets a bit shorter.

(Like a car’sodometer)

d i v i s i o n s



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A t b i r t h , t h e t e l o m e r e s i n m o s t h u m a n c e l l s a r e l o n g e n o u g h t o

s u p p o r t a b o u t 5 0 c e l ldivisions

Is there a Fountain of Youth?



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Cancer

These arecells that

rebuild theirtelomeresafter each

celldivision,restoring the

protective



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“ Can ce r c e l l s a r e t h o s e

w h i ch ha ve f o rgo t t en

ho w t o d i e .”

—Harold Pinter

day 8 september 19 chapter 5 scribd

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