Which of the following is NOT a characteristic that makes Drosophila an ideal model organism?

Which mechanism does NOT contribute to reshuffling of alleles in sexual reproduction in eukaryotes?

Explain in detail (use a drawing to support you explanation), why after each round of replication, the new daughter strand is ~20nucleotide’s shorter than the parent strand.

____ 22. The action potential
a. is a chemical that diffuses across a synapse.
b. transmits information from the cell body to the axon through the synapse.
c. is an electric current that passes through the axon and causes the release of neurotransmitters into
the synapse.

____ 24. Humans need _________ to move parts of the appendicular skeleton, such as the arm.
a. muscles
b. bones
c. joints
____ 25. An MRI reveals that a patient’s heart valves are inflamed. Doctor A says that the patient has coronary artery
disease. Doctor B says that the patient has rheumatic fever. Which doctor is most likely correct?
a. Doctor A, because the heart valves pump blood into coronary arteries.
b. Doctor B, because antibodies attack heart valves in rheumatoid fever.
c. Doctor A, because arterial clogging leads to hear valve fatigue.
____ 26. Which lists the layers of skin from outer to inner?
a. dermis, melanin
b. epidermis, dermis
c. melanin, epidermis
____ 27. A doctor find that her patient’s white blood cell count is higher than normal. What does this most likely
indicate?
a. The patient is healthy.
b. The patient has an infection.
c. The patient’s kidneys are functioning poorly.

4. Ms. Laila is examining the cellular organelles in the slide and she wants to study about the ribosomes. Answer the following based on Laila’s requirement. (2.5 Marks) a) What type of microscope is used to view these organelles?

b) Explain principle and working mechanism of the microscope which doesn’t penetrate the organelles but measures the size and structure.

Describe, in detail, how synthesis of a lagging strand of DNA occurs and WHY it is discontinuous. Be as descriptive as possible.

In Drosophila black body (B) is dominant to gray (b) and long wings (L) is dominant to short wings (l). The F1 flies were produced by crossing a homozygous black, homozygous long winged fly with a gray short winged fly. (4)

a) Give the genotypes of the Parents and the F1.

b) If an F1 is testcrossed, what is the expected phenotypic ratio?

c) If the F1 are allowed to interbreed what are the expected phenotypes and probably proportions in the F2 generation?

d) If the F1 is mated with a true breeding black and long winged fly, what would be the expected phenotype(s) and the probably proportions of the F2 generation

Your team has posed the question: Does MAD1 control the metaphase checkpoint? The hypothesis was: If MAD1 gives the signal to progress to anaphase after chromosomes have aligned, then a group of mutant MAD1 cells will more often have imperfect chromosome numbers after a series of cell divisions compared to normal cells.You investigated this question by comparing the cell division of cells that have the normal, or “wildtype” MAD1 gene to the division of cells with the mutant MAD1 gene. In your experiments, you compared the number of “aneuploid” cells (imperfect chromosome numbers) to the number of “euploid” (correct chromosome numbers) in your experimental group of MAD1 mutant cells and your control group of MAD1 normal cells.

Results: Average Percent of Aneuploid Cells after 24 hrs

Control:Normal MAD1 cells had an average of 10 percent aneuploid cells after 24 hours.

Experimental: Mutatnt MAD1 cells had an average of 30 percent aneuploid cells after 24 hours

Question:

Develop a conclusion based on these results. Is the hypothesis supported or rejected? Explain your reasoning.

(a) Describe how secondary structural elements fold to produce

(i) The Rossmann fold                      

(ii) The four-helix-bundle motif        

(b) Explain why proline is more often found at the ends of α-helices but not in the middle.

How are actin filament and microtubule assembly similar?

Ecological Advantages of Vegetable Production in Nigeria(15 slides presentation )

3. Mrs. Natasha gave birth to a boy child and her friend Mrs. Tina gave birth to a female child. When the babies are born, the environment is different both inside and outside of the body. Based on the above case answer your questions. (2.5 Marks)

a) How do the new born girl and boy babies are coping up with new environment?

b) What type of enzyme and neurotransmitters are involved with this process?

c) Is there any difference between these babies in coping up with the new environment? Comment on it.

d) Which type of tissue is involved in this process?

e) Mention the name of the gas which is involved in this process.

f) Write any two locations of this tissue.

What would happen in a cell that had a mutation that inactivated the protein WASP?