1. Explain why Phenol Red Lactose broth tubes are used for Water Quality testing.

2. A. What does it mean if a water quality analysis returns a positive result for the presence of E. coli? B. What is the meaning of the term indicator organism?

5. Early Monday morning you collect a water sample from a local beach. You set up an MPN test with the water sample, using one tube for each dilution. After the correct incubation time, you examine the tubes and discover positive results in the 1 ml tube, but the 10 ml and 0.1 ml tubes are negative.

A. Should the beach be opened? Explain your answer.

B. What could have caused the results you obtained? Be specific.

define circadian rhythm in  plants and explain what happens when an organism is artificially maintained in a constant environment

Use the pressure-flow model to explain what is likely to happen to water, pressure and solute potential in the following scenarios and how that is likely to affect sugar transport in the phloem:

a. Potatoes rapidly growing and accumulating starch.

b. An Arabidopsis thaliana mutant homozygous for a loss-of-function mutation in the sucrose-H+ transporter SUC2.

c. A plant watered with salty water accumulating higher than normal levels of Na+ and Cl- ions in the root xylem.

d. A plant in which all emerging fruit are removed.

e. Potential adaptation(s) in Sea Asparagus (Salicornia virginica) growing on BC ocean beaches to get sugar to move from photosynthetic leaves to non-photo-synthetic leaves. These plants transport Na and Cl ions in the xylem and secrete it from leaves.

What is a heterozygous B-thalassemia?

Question 10 (Mandatory) (1 point)

A serum ferritin level on a patient with a slight microcytic anemia due to a chronic disease will typically be ___________________.

Question 10 options:

Question 11 (Mandatory) (1 point)

Another name for a siderotic, or iron, granule is a ________________________.

Question 11 options:

Question 12 (Mandatory) (1 point)

The test which evaluates the binding ability of transferrin is the _____________________ test.

Question 12 options:

Question 13 (Mandatory) (1 point)

Most of the iron stored in the body is stored as __________________.

Question 13 options:

Question 14 (Mandatory) (1 point)

The ferritin level in Sideroblastic anemia would be __________________.

Question 14 options:

Question 15 (Mandatory) (1 point)

Which of the following would be seen in Sideroblastic Anemia?

Question 15 options:

Use logical operators in descriptions of rules and relationships in a problem situation.

Is this a good answer? Would you add anything to this answer? Thank you.

5) Gamma-delta T cells are Weird. (Yes, that capitalization is intentional.) Although they undergo V(D)J recombination to produce their γδ chains, they have a limited repertoire of gene segments to use, and apparently only certain combinations are stable (for example Vγ9/Vδ2), further limiting what antigens they can see. Additionally, they do not require seeing MHC molecules with peptides to function, suggesting they do not always see protein-based antigens. Weirder yet, some γδ T cell subsets have the ability to phagocytose antigen and themselves function as antigen-presenting cells. Some scientists argue that these features suggest that γδ T cells are an evolutionary ‘left-over’, a bridging cell type between ancient innate immune cell types and the more recently developed adaptive cell types.  

Identify two other pieces of evidence from the text or literature and explain why they do or don’t support the idea that γδ T cells are “missing links” of the immune system.

(8 points, 4 per explanation)

Answer:

Gamma delta T cells (γδ T cells) are T cells with a specialized T-cell receptor (TCR) on their outer covering or surface. Comparisons between the δ and γ V, D and J gene portions within the primate species have shown a fascinating order of how these loci have evolved (Holtmeier & Kabelitz, 2005). The gene segments of the δ locus have not changed considerably in the primate ancestry from humans to marmosets; the gene directive, overall, is well-looked-after and most of the genes remain purposeful with few duplications or deletions.

Evolutionary perspectives of the Gamma delta T cells:

Gamma delta T cells are an enigma of the immune system. Their triggers are not really understood. An attempt to explain their role as the cells that bridge the gap between innate and adaptive immunity doesn’t really justify their niche in the immune system, rather it focuses on their complex behavior. Therefore, hypotheses can be derived from the inferences that are made as a bid to explain their fundamental behaviors, as follows:

First Hypothesis:

The gamma delta T cells are placed at the borderline between the innate immune response that is quick in its action against any agents whether it be pathogens or micro-organisms, coming from outside, and the adaptive immune response which is extremely specific in its action and uses the B and T cells to tailor an immune response for the body, against the incoming foreign agents. This is basically because of the uniqueness of the gamma delta t cells which bear TCRs, that are mostly invariant in nature. A good example in this regard would be the Natural Killer T cells that bear the CD1d-restricted sites (Holtmeier and Kabelitz, 2005). This hypothesis says that gamma delta t cells are indeed, the missing links between the two evolutionary types of immunity.

Second Hypothesis

The second hypothesis is a reinforcement of the fact that gamma delta T cells really are the missing links between the evolutionary steps of immunity. Some evidence has surfaced in the recent findings that confirm recent work has shown that Vγ9/Vδ2 T cells in human are also proficient enough to carry out complex processes such as the phagocytosis, a function previously found to occur only in innate myeloid lineage cells such as neutrophils, monocytes and dendritic cells (Holtmeier and Kabelitz, 2005). This makes the fact very credible that these cells are actually the link between the two types after all.

Imagine that humans will someday evolve to have brains that are more resilient to Traumatic Brain Injuries (TBI) than those we have today. What anatomically and/or cellular changes might need to occur in the human brain for it to confer this resilience?

Compare and contrast the primary, secondary, tertiary and quaternary structures of Myoglobin(Mb) and Hemoglobin(Hb). You can create a Venn diagram or do columns listing the similarities and differences.  BE SPECIFIC

1. Duchenne muscular dystrophy (DMD) is caused by a relatively rare X-linked recessive allele. It causes progressive muscular wasting, and usually leads to death before age 20. What is the probability that the first son of a woman (who does not have the disease but whose father is affected) will be affected?

2. Hemophilia in humans is inherited as an X linked recessive trait. A woman whose father is hemophiliac marries a man with normal clotting ability. What is the probability that her first child will have hemophilia? Assume that the woman's mother is homozygous dominant.

3.In the ABO blood system in human beings, alleles A and B are codominant and both are dominant to the O allele.  In a paternity dispute, type AB women claimed that one of four men was the father of her type A child.  What blood types could the father of the child be on the basis of the evidence given?

1. In cats, coat color is controlled by a gene on the X chromosome. Yellow coat color is determined by the b allele and black coat color is determined by the B allele. The heterozygous condition results in a color known as tortoise shell.

a. What phenotypic ratio of offspring would be expected from a cross between a yellow male and a tortoise-shell female?

b. What proportion of the female offspring from a cross between a black female and a yellow male will be tortoise-shell (so, ignore the male offspring)?

2. In a certain species of flower, two autosomal genes, C and R, are both involved in flower color. The dominant C allele confers the ability to produce any color on the petal; cc individuals are white no matter what other genes they express. The dominant R allele produces red petal color; the flowers will be pink if they have two copies of the r allele. For the following cross, what is the phenotypic ratio?

CcRr x Ccrr

Why do hornwort sporophytes differ from those of all other plants?

• A. They have a foot and a basal meristem, so sporogenous tissue is formed continuously

• B. The leaves are short and round, but contain enough conductive tissue to maintain the entire structure

• C. They produce chemicals that are toxic to animals, so can only be spread by wind

• D. They sporophyte is much larger than the gametophyte, which is different than other closely related species

1. A) Why is it important to control illumination for live cells? B) Briefly explain how live cell imaging chambers can be used to control four parameters (name and indicate importance) that contribute to maintaining healthy cells.