Homework Help for Biology

Describe four factors(activation mechanisms) that can be optimized to obtain the maximum enzyme rate in the nonpolar organic solvents(e.g. hexane)

1) ESSAY[20 PTS]- A living cell is constantly "fighting" entropy. What does this mean in terms of a cell and how does the cell carry this out? Be sure to write legibly and in complete sentences in 4 to 5 paragraphs

Positive selection is observed whenever non-synonymous mutations in a gene have
a higher probability of fixation than synonymous mutations in a gene. In Tegula
species, a fitness advantage must explain such an elevated probability of fixation for
non-synonymous mutations in lysin or VERL. In thinking about the fitness achieved
through eggs (which are relatively expensive to produce) and sperm, explain why
you observed stronger positive selection on one of these genes.

Additional info: using MEGA software, the dN/dS ratio for lysin was 1.237 (positive selection) and the dN/dS ratio for VERL was about 1.0 (neutral selection).

1. Describe two reasons why ecosystem functions, such as productivity, may increase as species richness increases.

What parameters increase the stability of a dsDNA. Briefly explain each one.

A. Environmental (extrinsic) parameters:

B. Sequence-based (intrinsic, inherent) parameters:

22. What is one possible reason why nonstandard base pairing (wobble) is allowed during protein synthesis?

Note; please state the sources for the answers

common to the lymphatic system and the disorders of the system. 2. Discuss the effects of four different red blood cell conditions. 3. Identify the important signs and symptoms associated with polycythemia and Hodgkin’s lymphoma. 4. Describe the common diagnostics used to determine type or cause of bleeding disorders. 5. Identify common factors of the malaria. 6. Describe the typical course and management of the common lymphatic system disorders.

immunology, please just use around 200 words to help me understand. Describe one molecular pathway for T-cell activation. What is one of the pros of this pathway?

PLEASE REVISE:

An enlarged thyroid is swelling of the neck and is called a goiter. In goiter, the thyroid gland is not functioning properly. This growth will compress the esophagus and trachea leading to symptoms of coughing and the patient can’t breathe properly. Goiter is related to hypothyroidism and is always linked to thyroid & parathyroidism. The thyroid gland regulates the body's metabolism, while parathyroid glands regulate calcium levels and have no effect on metabolism.

Chapter 10

1.Outline the history of our knowledge on DNA up to Watson and Crick. What were the main contributions made by each researcher’s key experiment?

2.Explain the setup of the Hershey and Chase experiment, what would the results have been if protein was the genetic material?

3.Draw the structure of a DNA nucleotide, labeling each main component correctly. How does an RNA nucleotide differ?

4.If a section of double stranded DNA contains 19% Adenine, how much Thymine is present?

5.You are a researcher studying the genetic basis of heart attacks and have been working to determine the expression levels of different genes that might contribute to cancer formation. You obtain the DNA methylation status of five genes of interest (the data are shown in the table below). The plus (+) sign indicates the level of DNA methylation; more plus signs correlates with increased methylation levels.Based on this information which genes would you predict to have the highest rate of transcription?

What are the characteristics of the 3 main DNA forms?

Chapter 11

What are the different types of chromatin?

What are the structures and important roles for telomeres and centromeres?

What are the differences found between eukaryotic chromosomes and mitochondrial?

Chapter 12

Explain each of the different models of replication.

If you grow a culture of bacteria in media with radioactive nucleotides so that all DNA in the cells include radioactive nucleotides and then place the bacteria in new non radioactive media. After two rounds of replication what proportion of the DNA molecules will contain radioactivity?

Summarize the similarities and differences between rolling-circle replication, theta replication and linear eukaryotic replication.

What are the functions of the different DNA polymerases found in eukaryotic cells?

Draw a replication fork and include all key components and orientations. (Leading/lagging strands, DNA helicase, RNA primer and DNA gyrase)

What is the Holliday model of recombination and what are the necessary steps?

Chapter 13

What are the different types of RNA and what roles do they play?

Describe the properties and functions of each of the RNA polymerases and how they differ depending on the organism.

Describe in detail the process and mechanisms of transcription in both prokaryotes and eukaryotes.

Chapter 14

What are the primary purposes of each of the three post transcriptional modifications that occur in eukaryotic cells.

What is alternative splicing and what role does it play in the cell?

How is ribosomal RNA processed after transcription?

How do siRNA and miRNA work, describe/draw out the process in detail.

Describe how the first and second lines of defense of your innate immune system can protect you from an influenza A infection. Recall from week 7 course content topic “About Influenza Viruses” that influenza is a respiratory disease. Be specific about the tissues, cells, and processes involved and as related to influenza or other respiratory viral diseases.

In a woody dicotyledonous tree, which of the following parts will mainly consist of primary tissues?

(a) all parts

(b) stem and root

(c) flowers, fruits and leaves

(d) shoot tips and root tips.

Glycogen is a polymer of

(a) galactose

(b) glucose

(c) fructose

(d) sucrose.

How does cation exchange affect plants?

a. Cation exchange gives the roots of the plant a negative charge, which allows it to take up water more efficiently.

b. Cation exchange makes cations in the soil more available to plants.

c. Cation exchange makes cations in the soil more available to plants.

d. Cation exchange decreases the loss of water from plants by transpiration.