1. Liz has recently been diagnosed with hypertension and told to cut back on her dietary sodium. Explain how sodium affects blood pressure and provide practical suggestions that would help Liz reduce her sodium intake. In your response, consider the guidelines in the DASH (Dietary Approach to Stop Hypertension) diet.

2. Define the terms “free radical” and “antioxidant”. Explain how free radicals are formed in the human body and how antioxidant nutrients function in decreasing human disease.

Assume that a chemical of concern has a concentration of 12 mg/L in drinking water. Determine the dose of the chemical for adults and children. What is the cancer risk associated with this exposure if the slope factor is determined to be 0.065 (mg/kg-d)-1 for oral exposure? If 10,000 individual consumed this water over their lifetime what number would likely get cancer?

if LIA tubes were accidentally prepared with no glucose how the results of the test ne changed

What are the consequences of flu virus evolution for vaccination strategy? (in-depth please)

Disc 1

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The following Critical Thinking questions are meant to provide deeper understanding of biology topics after students have watched this week's Panopto lectures. Attempting to answers these before lectures have been watched, may compromise your understanding and participation in this course.

In the future, I will be subdividing the class into smaller online groups to answer these questions so it may be less intimidating for the "shy" person, but for this first one I wanted to do it as a class.

How do your get graded? Well, you are NOT graded on whether you answer the questions correctly! You are graded on how well you use critical thought from our lecture and chapter readings to synthesize answers. Your posts should NOT be long, multi-paragraph essays but rather concise statements that are well thought out. They can even be in the form of a question or inquiry such as "...I know that only proteins have disulfide bridges so if a stain binds to these groups then it should change color, however I'm not sure how that relates to the question...". Help each other out if some people are struggling to understand the question or are having difficulty seeing a point of view. Some questions may not have a correct answer! I will reveal the answers or possible answers after the due date.

For each question below post one critical thinking post and one critical thinking reply to another student before the due date (that's a total of 8 posts all together). Note that your posts doesn't have to answer the question completely...partial answers to a question are fine!

Macromolecules

1. Trans-fatty acids are a type of unsaturated fat. Most trans-fats consumed today are industrially created as a side effect of partial hydrogenation of plant oils (Crisco). In trans-fat molecules, the hydrogens on the doubly bonded carbon atoms (characteristic of all unsaturated fats) are straighter, rather than kinked, in shape. Why do you think trans-fats are considered unhealthy as compared to other unsaturated fats? Can you explain your answer chemically?
2. Why might an evolutionary biologist be interested in comparing the amino acid sequence of proteins between two different species? What differences might she find when comparing species that are distantly related or closely related? Explain.
3. Some viruses carry their genetic material as DNA while others, known as retroviruses, carry their genes as RNA. Virologists studying emerging viruses that might infect humans are interested in discovering which types would be the most difficult for our immune system to fight. Viruses that mutate quickly and thus, are able to thwart our immune defenses are the most concerning. Which of these two viruses, DNA or RNA, do you think mutate faster? Explain.

1. What types of foods are fortified? Give an example.

2. In order for fortified foods to have their intended impact, what things are necessary?

3. Do consumers need to be aware that a food is fortified in order to receive benefits?

4. Are fortified foods necessarily good for us? Give an example of a fortified food that could also be high in added sugars, saturated fat, and sodium

5. Do you think food fortification is still necessary in the United States today? Why or why not?

One difficulty in extracting sequencing reads that correspond to mitochondrial DNA from mixed fragments of nuclear and mitochondrial DNA is the nuclear genome contains segments homologous to regions of the mitochondrial genome called "numts." Mammalian genomes contain 50-450 kb of numts (the human genome contains 1005 numts, averaging 446 bp).

Estimate the fraction of reads from fragments of mammoth DNA that are likely to be numts. The mammoth genome is approximately 4.7x10^9 bases in length.

Describe the fluid mosaic model of the phospholipid bilayer.

Explain how the humoral immunity and cellular immunity work together.

10a. Name the three post-transcriptional processing events that take place to generate a mature mRNA from a nascent transcript?

1. ________________________________________________________

2. ________________________________________________________

3. ________________________________________________________

b. Describe a specific example of how one of these processing events can provide functional diversity for a given gene.

please explain in simple details.

what is magnaporthe oryzae?

is it a fungus? where does it come from?

how does it affect plants?

how does it impact the enrvironmet?

how does the disease cycle start?

9. The process of DNA replication creates a particular problem for replicating the ends of linear chromosomes.
a) Describe why the DNA replication machinery has difficulty replicating DNA ends.

b) Telomerase has been identified as an enzyme that can reverse the outcome of end replication.
Describe the near-universal mammalian chromosome telomere sequence and how telomerase solves the problem of end replication.

1. Describe common modifications of stems. Which ones are important for human use, and why?

2. Discuss the function of a fleshy fruit. How do humans use fleshy fruits? Is the relationship with humans beneficial for these plants?

1. Alpha thalassaemia is a blood condition resulting from abnormal haemoglobin production, due to loss of function of copies of either HBA1 or HBA2 genes. These genes are very similar and next to each other on the chromosome; for simplicity’s sake we talk about having four copies of the HBA gene (two alleles, with two HBA copies on each allele).

Alleles are depicted with α representing a functioning HBA gene, and - representing a non-functioning gene. For example, the genotype α-/αα represents someone with one allele with only one HBA copy functioning, and a second allele with both HBA copies functioning.

There are multiple phenotypes of alpha thalassaemia, which generally depend on how many of the four HBA copies are functioning. This is outlined in the table below:

Both Indian and Southeast Asian populations have relatively high rates of alpha thalassaemia.

In Indian populations, alleles with one HBA gene copy deleted are the common cause of alpha thalassaemia conditions. Alleles with both HBA gene copies deleted are rare.

In Southeast Asian populations, alleles with both HBA gene copies deleted are the common cause of alpha thalassaemia conditions. Alleles with one HBA gene copy deleted are rare.

You are providing genetic counselling to an Indian couple, both of whom have alpha thalassaemia trait due to mutations commonly seen in their population.

Regarding alpha thalassaemia, what are the phenotypes possible for a pregnancy for this couple? Give the chance of each phenotype.

1. Diagram and discuss the structure of a woody stem. Which tissues are economically important? Why?

2. Flowers are sometimes referred to as ‘pets of the plant world’. Explain this statement. How did alliance with humankind affect the evolution of plants cultivated for their flowers?