AP Biology Gene Regulation and Development Review

Transcription

1 AP Biology Gene Regulation and Development Review

2 1. What does the regulatory gene code for? 2. Is the repressor by default active/inactive? 3. What changes the repressor activity? 4. What does repressor do? 5. Significance?

3 1. What does the regulatory gene code for? repressor 2. Is the repressor by default active/inactive? inactive 3. What changes the repressor activity? Presence/absence of corepressor 4. What does repressor do? Blocks transcription 5. Significance? Turns gene off

4 1. What is a receptor and a ligand? 2. Where are each found? 3. How do the two interact? 4. What can affect their interaction?

5 1. What is a receptor and a ligand? 2. Where are each found? 3. How do the two interact? 4. What can affect their interaction? A receptor is a protein on the cell s membrane. If the molecular shape of a signaling molecule (ligand) matches with the receptor, it can bind, cause transduction that results in a response A mutation that affects the shape of the receptor can cause binding with the ligand to fail

6 Peptide Ligands 1. What is the ligand (signalingmolecule)? 2. Why can it not pass through the membrane? 3. Where is the receptor located? 4. What does transduction do? 5. What is the response?

7 1. What is the ligand (signaling-molecule)? Growth factor 2. Why can it not pass through the membrane? It is a large protein 3. Where is the receptor located? Cell membrane 4. What does transduction do? Sends signal into the cell 5. What is the response? Gene transcription

8 A B 1. Hh is a ligand (signaling molecule). Why is there a difference in transcription of the target gene in A and B? 2. How could researchers block transcription even if Hh (ligand) were present?

9 A B 1. Hh is a ligand (signaling molecule). Why is there a difference in transcription of the target gene in A and B? Presence of Hh in B inactivates the repressor 2. How could researchers block transcription even if Hh (ligand) were present? Block transduction

10 Match the letter labels to the diagram below:

11 = enhancer

12 Make sure you understand the Pitx1 gene models (see your packet).

13 The Central Dogma DNA mrna protein 1. What is the label that should be found on top of each arrow? 2. Where does each of these processes take place?

14 The Central Dogma DNA mrna protein 1. What is the label that should be found on top of each arrow? Transcription, then translation 2. Where does each of these processes take place? In the nucleus for transcription (RNA polymerase makes a copy of a gene) and in the cytoplasm on a ribosome for translation

15 1. What evidence would suggest that transcription of a specific gene is being inhibited? 2. What evidence would suggest that translation, not transcription is being inhibited?

16 1. What evidence would suggest that transcription of a specific gene is being inhibited? Little or no mrna for that gene is present, and since little or no mrna is present, little or no protein as well 2. What evidence would suggest that translation, not transcription is being inhibited? mrna for the gene is present, but the protein is not

17 Which biotechnology approach could be used to identify betaglobin mrna in a sample of total cellular RNA?

18 Which biotechnology approach could be used to identify betaglobin mrna in a sample of total cellular RNA? 1. Electrophoresis 2. DNA acts as a probe and separated mrna marks betaglobin mrna based on size 2. Singlestranded DNA complement ary to betaglobin mrna added

19 = wild-type (AA) 2 = cystic fibrosis (aa) 3 = child 1 4 = child 2 5 = ladder What is the genotype of child 1 and child 2? Use RFLP analysis to justify your answers:

20 = wild-type (AA) 2 = cystic fibrosis (aa) 3 = child 1 4 = child 2 5 = ladder Child 1 (lane 3) has cystic fibrosis (aa) Child 2 (lane 4) does not (AA)

21 Is the genetic disorder dominant or recessive? Justify: 2. What are the genotypes of the parents? 3. What is the genotype of child #2? 4. What is the genotype of child #3? 5. How do the genotypes relate to the RFLP pattern shown in the gel? 6. Could the gel be used to genotype the kids? Explain:

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23 If intracellular levels of iron become high, cells synthesize an iron-storing protein called ferritin (see left).

24 1. Is translation of the ferritin mrna stimulated or inhibited by the presence of iron? 2. What is the mechanism whereby the translation of the ferritin mrna is stimulated?

25 1. Is translation of the ferritin mrna stimulated or inhibited by the presence of iron? stimulated 2. What is the mechanism whereby the translation of the ferritin mrna is stimulated? Inactivated IREbinding protein, allowing ribosome to bind to mrna

26 Hereditary hemochromatosis is an iron storage disease. There is a decreased uptake of iron into cells. Instead, iron builds up to toxic levels in the blood.

27 What process is involved in the morphogenesis shown in both the tadpole and mouse paw?

28 What process is involved in the morphogenesis shown in both the tadpole and mouse paw? Apoptosis programmed cell death, cells die, nutrients reabsorbed

29 Cytoplasmic Determinants (CDs): 1. CDs play an important role in which stage of embryonic development? 2. What is the origin of CDs? 3. What are CDs? 4. Are CDs evenly distributed in the egg and in the twocelled embryo?

30 Cytoplasmic Determinants (CDs): 1. CDs play an important role in which stage of embryonic development? Very early embryo 2. What is the origin of CDs? Maternal (egg) 3. What are CDs? ligands 4. Are CDs evenly distributed in the egg and in the two-celled embryo? No

31 Induction: 1. Induction plays an important role in which stage of embryonic development? 2. What is the mechanism involved?

32 Induction: 1. Induction plays an important role in which stage of embryonic development? Early embryo 2. What is the mechanism involved? Signal transduction pathway

33 A C B A Induction: 1. What are the labels for A, B and C 2. Describe the action shown for each step (A, B, C) 3. How is the blue (lower) cell affecting the brown (upper) cell?

34 A C B A Induction: 1. What are the labels for A, B and C A = ligand, B = receptor, C = transduction 2. Describe the action shown for each step signals, receives, sends message to the nucleus 3. How is the blue (lower) cell affecting the brown (upper) cell? The lower cell is instructing the upper cell

35 1. Where (in the unfertilized egg) is bicoid mrna most concentrated? 2. What happens to bicoid mrna in the early embryo (after the egg is fertilized)? 3. Describe this pattern in terms of a [ ] gradient: 4. What is the outcome of this gradient?

36 1. Where (in the unfertilized egg) is bicoid mrna most concentrated? In the anterior end 2. What happens to bicoid mrna in the early embryo (after the egg is fertilized)? translated 3. Describe this pattern in terms of a [ ] gradient: high to low 4. What is the outcome of this gradient? Head formation

37 Anterior Shown above is a representation of the 29 vertebraesegments of a mouse. 1. In which vertebrae-segments is Hox 6 expressed? 2. The beginning of Hox 6 expression marks the end of which type of vertebrae and the beginning of which other type? Posterior

38 Anterior Shown above is a representation of the 29 vertebraesegments of a mouse. 1. In which vertebrae-segments is Hox 6 expressed? The beginning of Hox 6 expression marks the end of which type of vertebrae and the beginning of which other type? Cervical, thoracic Posterior