Gene Expression, Inheritance Patterns, and DNA Technology

1. Gene Expression, Inheritance Patterns, and DNA Technology This Powerpoint contains information for chapters 11, 12, and 13.

2. Gene Expression Role • Activation of gene = ____________________ • When transcription occurs • Mechanisms ensure that each protein is produced only when needed • 2 steps = ________________________________________

3. Gene Expression in Prokaryotes • Francois Jacob and Jacques Monod • Discovered how genes control metabolism of sugar lactose E. Coli • See Concept Map

4. Gene Expression in Eukaryotes • Vastly different from prokaryotes • Larger ______________ • DNA located in several individual chromosomes instead of single circular one • Most are __________________________________ • Expression is far more complex • No _______________ found in eukaryotes

5. Three regulatory elements: • Structural genes: ____________________ • Promoter: __________________________ • Operator: __________________________ • All three of the above terms form the _______________________________ • What is the lac operon?

6. Let’s talk about E. coli • Lactose…found in cows milk…disaccharide (glucose + galactose) • Let’s say you drink a glass of milk: • Lactose entering your body _______________________________________________ • Control the metabolism of lactose • Adjacent on chromosome • Production is controlled by 3 regulatory elements

7. Repressor attaches to operator

8. If lactose is absent… • Repressor protein attaches to ____________ • Inhibits a specific gene from being expressed • Prohibits ______________from binding to structural genes = no _______________

9. Jobs on structural genes • Introns – _________________________________ • Exons – __________________________________ • Unsure of benefits of intron-exon pattern • May provide options for producing different _________ • Could facilitate the exchange of exons among homologous chromosomes during crossing over in meiosis = _________________________ • Pattern could serve as an additional source of the genetic diversity that is essential for evolution

10. Control after transcription • Gene expression can be controlled by modifying _____ after _________________________ • __________ – lg. molecule; from transcription of introns and exons • Enzyme comes in and splits the pre-mRNA at each end of an intron and then splices the exons together, forming ________________ • mRNA leaves nucleus and enters the cytoplasm • mRNA begins the manufacturing of proteins on the ribosomes • BUT WE ALREADY KNOW THIS!!!!

11. Nature of Cancer • Tumor – uncontrolled, abnormal cell division • Benign – ________________________________________________________________________________________________ • Malignant – _____________________________________ • Metastasis – ____________________________________

12. Kinds of cancer • Carcinomas – ______________________________________________________________________________________________ • Sarcomas – ____________________________________ • Lymphomas – solid tumors that grow _____________________________________________________________________________________________________________________________________________

13. Cancer and the cell cycle • Normal cell division – divide when needed and when conditions are right; governed by ______________________________________________________________________________________ • Adequate nutrition • Attachment to other cells, membrane, or fibers between cells • Cancer cell division – continue to divide in dense environments • _____________________________________________ • Continues to divide after _______________________________________________

14. Causes of cancer • Mutations that alter the expression of genes coding for growth factor proteins • Can be ________________________ • Mostly caused by ________________________________________________________________________________________________ • Depends on factors • Maybe genetic predisposition (mutations in gametes can be passed to offspring) • Exposure time to _______________ • Amount of ____________________ • More than one ________________ is usually needed to produce cancer

15. Oncogenes • Begin as _______________– normal genes; control cell growth and differentiation • Normally code for ______________ • Regulate ________________________________________ • Mutation in proto-oncogene • Produce more ________________________________________________________________________________________________ • Increases rate of cell cycle = ___________________

16. Tumor-suppressor genes • Code for ________________________________ • Mutations = proteins for which they code are either expressed _____________________________________________________________________________________________________________________________________________

17. Viruses and Cancer • Many viral genes are ________________ • Viruses can stimulate _________________by causing ______________________________________________________________________________________________ • Viruses may activate the cell’s own _________________ • Found to cause various types of ___________________

18. Review • Know all vocabulary (would you expect anything less?) you know, morphogenesis, homeoboxes, introns, exons, etc. • Know the pictures depicting gene expression in prokaryotes and eukaryotes and what is happening (be able to identify what is happening and where; steps) • make sure you understand the lac operon! • steps leading to formation of protein in eukaryotic cells • Know difference between oncogene and tumor-suppressor gene • Know how Drosophila is used as an example with regards to mutations. • Know how genes can be expressed – the process • Know types of cancer and what happens for a cell to become cancerous

19. Sex Determination • Thomas Hunt Morgan • Studied __________________ • 4 Pairs of ______________________________ • Noticed one pair was different between males and females • X – appeared same in male and females • Y – shorter, hook shaped • Gametes from meiosis II have either ____________________(depending on sex of parent)

20. Sex Determination (cont.) • Morgan believed ____________________ it to carry more genes • X = X-linked genes • Y = Y-linked genes • Genes on sex chromosomes = ___________________ • Morgan’s fruit fly experiments confirmed the existence of X-linked traits

21. Morgan’s findings on eye color • White-eyed male x red-eyed female = (followed Mendel’s predictions) • F1 generation all had __________________ • Crossed F1 generation = F2 generation exhibited _______________________________________________ • Hypothesized that the gene for ______________________________________________________________________________________________

22. Linkage groups • Linked genes tend to be ___________________ • Typically a _______ ratio • If on a different chromosome, they are _________________ • Key: Grey (G) is _______________ to black (g); Long (L) is ____________________ to short (l) • Morgan crossed: GGLL x ggll • F1 = GgLl; crossed two F1 generations • F2 = Morgan thought if alleles were on different chromosomes, should _______________________ • Phenotypic ratio should be ____________ • If on same chromosome, __ gray, long-winged: __ black, short-winged • Result closely approximated the ___________ • Hypothesized that genes are linked

23. What about … • Gray, short-winged and black, long-winged appearing? • If on same chromosome, must be some kind of _______________________________ • Possibly couldn’t be ________________ = Occur in one individual out of tens of thousands • Rearrangement occurred during _________________ • Rearrangement of alleles = _______________________________________________________________________________________________________________________________________________________________

24. Chromosome Mapping • Alfred H Sturtevant • Morgan’s student • Used ____________________________________________________________________________________of Drosophila • Know what a chromosome map is, you won’t have to calculate map units, etc.

25. Mutations • Chg in DNA of organism • Entire ________________ or single ___________________ • Germ Cell = ______________________________________________________________________________________________ • Somatic = ______________________________________ • Lethal = death, often before birth • Beneficial? = better chance of reproducing and have evolutionary advantage • Variation upon which natural selection acts

26. Chromosome Mutations • Deletion= _____________________________________ • Inversion= ____________________________________ • Translocation= ________________________________ • Nondisjunction= _______________________________ • Ex. ____________________________________________

27. Gene Mutations • Point = substitution, addition, or removal of • Substitutions = __________________________________ • Nucleotide Insertions – ________________________________ • Nucleotide Deletions - ________________________________ • Frame-shift = __________________________________ • What happens?

30. 12.2 (Page 230-231 only) • Familiarize yourself with Table 12-3 on page 230 • Disorders due to _________________________ • Can cause gametes to lack a ________________________________________________ • Zygotes (______________) can have either 45 or 47 (often __________) • 45 = ____________________ (one copy of chromosome) • 47 = ____________________ (three copies)

31. Trisomy • Trisomy 21 = extra copy of _______________________= Down Syndrome List 5 characteristics:

32. Down Syndrome

33. Nondisjunction and sex chromosomes • Males with extra copy of _____ = __________________________________________________ • Some feminine characteristics • Some are mentally retarded • Some are infertile • Individuals that inherit ______________do not survive = ___________contains information essential for development • Individuals that have __________________= Turner’s syndrome • Female appearance • Do not mature sexually • infertile

34. Klinefelter’s Syndrome

35. Turner’s Syndrome

36. DNA Technology • Used to ______________________________________________________________________________________________ • Trace the path of the restriction enzyme using 5 post-its…be able to explain what is happening. Use your text, pages 239-240 to better gain an understanding for your explanation.

37. How does it all happen? • DNA is a long chain of _______________________ • _________________________________ cut DNA into more manageable segments • ___________________ are created • Readily bind to _____________________________________ • Can be used to isolate a _________________________ • A __________________can transfer the gene to an organism

39. Transplanting Genes • What would be the need to transplant genes? Talk with your table and discuss.