Question

1. What type of proteins are often found in lipid rafts?

a. Peripheral membrane proteins

b. GPI-anchored proteins e.g. proteins involved in signaling

c. Enzymes

2. During the “green revolution” a wheat mutation was identified in the gene rht1. The wild-type RHT1 protein turned out to be a protein that has a DELLA domain. The rht1 mutant wheat protein was found to lack a DELLA domain. What was the effect of this rht1 mutant protein in regards to GA signaling?

a. By missing the DELLA domain, the rht1 protein was targeted for proteolysis, and GA specific transcription factors were no longer repressed.

b. By missing the DELLA domain, the rht1 protein was able to resist proteolysis, and GA specific transcription factors were repressed.

c. By having the DELLA domain, the rht1 protein was able to resist proteolysis, and GA specific transcription factors were repressed.

3. You want to observed the behavior of a GFP-labeled protein in a live tobacco BY-2 cells. Which of the following methods would you use?

a. Light microscopy

b. Confocal microscopy

c. Laser capture dissection microscopy

d. Transmission electron microscopy

4. Green fluorescent protein can be expressed as a chimeric protein. This means that GFP can be ______.

a. Fused to another protein of interest and expressed as a fusion protein.

b. Only expressed by itself

c. Only fused to the N-terminus of a protein and expressed as a fusion protein

d. Only fused to the C-terminus of a protein and expressed as a fusion protein.

5. The mutant screens revealed the receptors of NFR1 and NFR5 that are found on the surface of the root epidermal cells. What was the ligand that the NFR1 and NFR5 recognize?

a. Cytokinin

b. Bacterial flagellin e.g. fig 22

c. N-acetylglucosamine polymers e.g. NOD factors

d. Bacterial cell walls.

6. The wild-type Hit1 gene encoded a protein that was called LHK1. What type of protein is LHK1?

a. Serine-threonine kinase

b. Receptor tyrosine kinase

c. Histidine kinase

d. Calcium-dependent kinase

7. The hormone cytokinin binds to LHK1. What organ is formed in the root as a result of the signaling from this hormone?

a. Nodule

b. Root hairs

c. Cortex

d. Xylem

8.To determine what parts of a promoter either activate or repress a genes expression you have designed a transgenic experiment. Select which of the following experiments is the best to test the function of your promoter of interset.

a. Delete the entire promoter sequence and fuse it to a reporter gene i.e. GFP

b. Delete individual fragments of the promoter sequence and fuse it to a reporter gene i.e. GFP

c. Delete only one fragment of the promoter sequence and fuse it to the gene behind your promoter

d. Add in another promoter sequence in front of your promoter sequence and fuse it behind your gene’s promoter.

9. What resolution does an epifluorescence microscopy use?

a. 0.1 nm

b. 30 - 50 nm

c. 200 nm

10. We looked at two types of mutant screens that were performed in legumes. Which of the following was NOT on of the screens that we examined?

a. Selection of non-modulating mutants

b. Selection of hyper-modulating mutants

c. Selection of nodulating mutants.

Answer 1

Q -(1)

Ans-( b) GPI-anchored proteins

Lipids rafts are regions of membranes with a distinct characteristics structural composition and that appear to act as platforms to colocalize proteins involved in intracellular signaling pathways.cytoplasmic proteins that are covalently modified by saturated fatty acids and cell surface proteins that are attached via a glycosyl phosphatidylinositol anchor are highly concentrated with lipid rafts.

Q-(2)

Ans-(a) By missing the DELLA domain , the rht1 protein was targeted for proteolysis , and GA specifice transcription factors were no longer repressed .

DELLA , a subset of the plant specific GRAS family of putative transcription regulators are key intracelluar repressors of GA responses . DELLA repress seed germination , growth and almost all known GA - dependent processes , were as GA relieves their repressive activity .

Q(3)

Ans-(c)- Laser capture dissection microscopy .

Expression of genes incoding GFP within cells has engendered experiments that could not be imagined ten years ago , details of the use of particular fluorescence , confocal laser scanning or multiphoton microscopes to visualize GFP derived fluorescent proteins will not be covered but can be found in many cited references .

Q(4)

Ans-(d) Only fused to the C-terminus of a protein and expressed as a fusion protein .

GFP is an invaluable new tool for studies of molecular biology and cell physiology . as a marker of transfection in vivo, it provides a simple means of identifying genetically modified cell to be used in physiological studies .

Q(9)

Ans- (c)