Transcript Gene Expression, Inheritance Patterns, and DNA Technology

This Powerpoint contains information for chapters 11,
12, and 13.
Gene Expression Role
 Activation of gene =
____________________
 When transcription
occurs
 Mechanisms ensure that
each protein is
produced only when
needed
 2 steps =
____________________
____________________
Gene Expression in Prokaryotes
 Francois Jacob and Jacques Monod
 Discovered how genes control metabolism of sugar
lactose E. Coli
 See Concept Map
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
Three regulatory elements:
 Structural genes: ____________________
 Promoter: __________________________
 Operator: __________________________
 All three of the above terms form the
_______________________________
 What is the lac operon?
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
 Repressor
attaches to
operator
If lactose is absent…
 Repressor protein attaches to ____________
 Inhibits a specific gene from being expressed
 Prohibits ______________from binding to structural
genes = no _______________
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
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!!!!
Nature of Cancer
 Tumor – uncontrolled, abnormal cell division
 Benign –
________________________________________________
________________________________________________
 Malignant – _____________________________________
 Metastasis – ____________________________________
Kinds of cancer
 Carcinomas –
_______________________________________________
_______________________________________________
 Sarcomas – ____________________________________
 Lymphomas – solid tumors that grow
_______________________________________________
_______________________________________________
_______________________________________________
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
_______________________________________________
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
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 = ___________________
Tumor-suppressor genes
 Code for ________________________________
 Mutations = proteins for which they code are either
expressed
_______________________________________________
_______________________________________________
_______________________________________________
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 ___________________
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
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)
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
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
_______________________________________________
_______________________________________________
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
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 =
_____________________________________________________
_____________________________________________________
_____________________________________________________
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.
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
Chromosome Mutations
 Deletion= _____________________________________
 Inversion= ____________________________________
 Translocation= ________________________________
 Nondisjunction= _______________________________
 Ex. ____________________________________________
Gene Mutations
 Point = substitution, addition, or removal of
 Substitutions = __________________________________


Nucleotide Insertions – ________________________________
Nucleotide Deletions - ________________________________
 Frame-shift = __________________________________
 What happens?
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)
Trisomy
 Trisomy 21 = extra copy of _______________________=
Down Syndrome
List 5 characteristics:
Down
Syndrome
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
Klinefelter’s Syndrome
Turner’s Syndrome
DNA Technology
 Used to
_______________________________________________
_______________________________________________
 Trace the path of the restriction enzyme using 5 postits…be able to explain what is happening. Use your
text, pages 239-240 to better gain an understanding for
your explanation.
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
Transplanting Genes
 What would be the need to transplant genes? Talk
with your table and discuss.