The trp operon: Bacterial cells can take up the amino acid tryptophan from their surroundings, or, if the external supply is insufficient, they can synthesize tryptophan from small molecules in the cell.  

When external supplies of tryptophan are plentiful, the cells suppress transcription of the trp operon, which encodes the tryptophan biosynthetic enzymes. When external supplies of tryptophan are not plentiful, the cells express the trp operon.

The trp operon repressor protein inhibits transcription of the genes in the trp operon. Upon binding tryptophan, the tryptophan repressor binds to a site in the promoter of the operon and represses transcription.

A. (2 pts) Why is tryptophan-dependent binding to the operon a useful property for the tryptophan repressor?

B. (4 pts) How would regulation of transcription of tryptophan biosynthetic enzymes be affected in cells that express a mutant form of the tryptophan repressor that (i) cannot bind to the DNA or (ii) bind to DNA even when no tryptophan is bound to it? Also address how tryptophan synthesis would be affected and how that would affect the cell. Please bullet point your response (i) and (ii) for each mutant for ease of grading.

Explain, in great detail, the protocol of DNA isolation. In your explanation, mention which steps and/or materials are important in the process, and explain the significance of these steps. Following your explanation, describe where, in the protocol, can contamination occur and cause DNA isolation to fail.

True or False: (PE = Physical Education)
1. A degree in Physical Education was historically viewed from a "generalist" perspective
2. Because of the nature of “physical education activities,” the physical educator isn’t concerned with standards of health and moral and ethical development of students.
3. The impulsive developmental aspect can determine attributes such as character and moral values
4. The advent of "specialization" is not a consequence of the growing knowledge in the academic discipline of physical education and the need of qualified professionals in a specific field
5. Leadership can be considered the key to meeting PE objectives
6. Each person’s experiences determine their truth about the meaning of physical education.
7. Physical Education objectives are chosen only on the needs of the individual
8. The "quality" of any developmental area and subsequent adjustment is influenced by a predetermined standard.
9. In physical education only neuromuscular and organic adjustment are considered as specific objectives
10. Adjustment can be considered essential in order to live
11. Standards should be evident in all aspects of development and adjustment
12. Bio-mechanics and Sport history are not considered sub-discipline of physical education
13. Learning and acquiring skill in a variety of movement forms is not essential in neuromuscular development
14. When referring to the objective of leadership in physical education it can be a process that determines the type of results.
15. Standards are based upon the conceptions of the individual and/or profession

1. In general, Bacteria predominate in __________ waters, while numbers of Archaea are about equal or show a slight predominance in __________ waters.

A) upper / lower                                             B) mid-range / upper and lower

C) upper and lower / mid-range                     D) lower / upper

2. Mycorrhizal fungi obtain their carbon from ________ and their inorganic minerals from __________.

A) root secretions / particles produced by the photosynthetic actions of other parts of the plant

B) the soil / particles produced by the photo-synthetic actions of other parts of the plant

C) the soil / root secretions

D) root secretions / the soil

3. The absorption of __________ by chlorophylls begins the process of __________.

A) ATP / photosynthetic energy conversion

B) light energy / phototrophic energy conversion

C) ATP / autotrophy

D) light quanta / autotrophy

4. Which statement(s) is/are true?

A) Some methanogens are endosymbionts of certain protozoa.

B) A competing H₂-consuming process to methanogenesis is acetogenesis.

C) Methanogenesis is carried out by a group of Archaea, the methanogens, which are strict anaerobes.

D) All of the above are true.

5. Genes encoding __________ are widely used as target genes in molecular biodiversity studies.

A) 16S rRNA                          B) reverse transcriptase

C) ATPases                             D) DNA polymerase III

6. True or false:

T/F More dense populations of phototrophic microorganisms would be found in near-shore areas than in pelagic waters.

T/F Hydrothermal vent animals are known to live off the products of the chemolithotrophic microbial symbionts.

T/F Excretions from roots hinder, rather than promote, the development of microorganisms in the rhizosphere.

True or False: (PE = Physical Education)
1. A degree in Physical Education was historically viewed from a "generalist" perspective
2. Because of the nature of “physical education activities,” the physical educator isn’t concerned with standards of health and moral and ethical development of students.
3. The impulsive developmental aspect can determine attributes such as character and moral values
4. The advent of "specialization" is not a consequence of the growing knowledge in the academic discipline of physical education and the need of qualified professionals in a specific field
5. Leadership can be considered the key to meeting PE objectives
6. Each person’s experiences determine their truth about the meaning of physical education
7. Physical Education objectives are chosen only on the needs of the individual
8. The "quality" of any developmental area and subsequent adjustment is influenced by a predetermined standard
9. In physical education only neuromuscular and organic adjustment are considered as specific objectives
10. Adjustment can be considered essential in order to live.
11. Standards should be evident in all aspects of development and adjustment
12. Bio-mechanics and Sport history are not considered sub-discipline of physical education
13. Learning and acquiring skill in a variety of movement forms is not essential in neuromuscular development.
14. When referring to the objective of leadership in physical education it can be a process that determines the type of results
15. Standards are based upon the conceptions of the individual and/or profession

Which minerals and vitamins are involved in reproductive failures commonly reported in animals and poultry?

Discuss 2 physiological changes experienced by the human body when in a mindful resting state and how they might affect the cardiovascular system.

put the following processes of protein synthesis translation steps in the correct order :

A- the next aa2-tRNA attach to the second codon on mRNA located in A site

B- then large ribosomal subunit binds the small ribosomal subunit forming an active ribosome

C- the ribosome breaks down and the mRNA dissociates and protein is released

D- the ribosome small subunit binding to the mRNA

F- the first amino acid moves to exit site and leaves the ribosome

G- ribosome moves on mRNA and by 1 codon this process is called translocation

H- the tRNA is charging with amino acid at 3' OH end

i - the aa1-tRNA carries the anticodon attaches directly with mRNA in the start codon located in P site

1-

2-

3-

4-

5-

6-

7-

8-

1. How many pairs of setae are there in each segment of the worm？Does each segment have setae?
2. What body region or segment are the walking legs attached to? What about the swimmerets?
3. What is the function of these gills?
4. Try to identify and explain what the crayfish had been eating:

5. Inside the stomach locate the gastric mill, a hard serrated structure. Study it closely by running a finger along the tooth-like margin.

   What is this structure’s function?

6. What are the functions of the skin gills and pedicellariae?

1. Attenuation is a regulatory mechanism that has been well studied in the E. coli trp operon, involved in tryptophan biosynthesis. Which of the following accurately describes attenuation?
A: The goal of attenuation is to suppress the expression of biosynthetic enzymes when the end product of the pathway is available.
B: The attenuator is a stem loop structure at the 5´ end of the mRNA transcript that resembles the structure of the factor-independent termination sequence.
C: When tryptophan levels are low, the trp operon transcript is attenuated before the operon's structural genes are transcribed.
D: Attenuation allows fine-tuning of the levels of mRNA transcript from the trp operon in response to small changes in the availability of tryptophan.
E: The trpL mRNA contains a "stall" sequence for the ribosome that includes two adjacent trp codons.

----

2. Which of the following are true statements concerning the similarities and differences between prokaryotic and eukaryotic DNA replication:
A: Prokaryotes use DNA polymerase III as the primary replicative enzyme, whereas eukaryotes use DNA polymerase I.
B: Most prokaryotes replicate a single chromosome from a single origin of replication, whereas eukaryotes have thousands of origins of replication spread over multiple chromosomes.
C: In eukaryotes, DNA replication is continuous, whereas prokaryotes replicate their DNA discontinuously in a process that generates Okazaki fragments.
D: Eukaryotic DNA replication is more complex than prokaryotic replication, because eukaryotes must dissociate and replicate chromatin as part of the process.
E: A homodimer of DNA polymerase III catalyzes the replication of both leading and lagging strands in prokaryotes, whereas two different DNA polymerases are required to replicate the leading and lagging strands in eukaryotes.

-----

3. Ammonia is toxic and must be converted to urea in order to be excreted. The following statements describe the process:
A: ammonia is transported into the liver as either alanine or glutamine.
B: transamination is a key step in the release of ammonia from glutamine.
C: urea is formed and excreted primarily by the kidneys.
D: alanine carries ammonia waste from muscle to the liver; once in the liver, alanine is converted via pyruvate to glucose, which may be returned to the muscle.
E: carbamoyl phosphate is a key intermediate in the conversion of ammonia to urea.
F: urea is ultimately formed by hydrolysis from ornithine

Explain deviation from Mendel's model of the inheritance of traits(ie. his principles/theory of inheritance)  (.

please use the terms below in your answer)

Chi-square

Linked genes

map distance

Multiple alleles

Poly genic

Mitochondrial DNA

Maternal inheritance

In corn, the following allele pairs are on chromosome 9: colored (C) vs. white (c) aleurone color; starchy (Wx) vs. waxy (wx) endosperm; and full (Sh) vs. shrunken (sh) endosperm. F₁ plants heterozygous for all three alleles were test crossed; the resulting progeny had the following phenotypic ratios:

colored, waxy, shrunken 116

colored, starchy, full 601

colored, starchy, shrunken 2538

white, starchy, shrunken 4

white, starchy, full 113

white, waxy, full 2708

white, waxy, shrunken 626

colored, waxy, full _____2

6708

Determine the order of and distances between the three genes.  Also determine the coefficient of

coincidence (C) and the interference (I).

The undigested antibodies and pepsin digested antibodies were tested for haemagglutination. In the haemagglutination assay, the titre for undigested antibodies is 8 and pepsin digested antibodies is 4. why pepsin digested abs has lower titre compared to undigested abs. State 2 reason.