Questions
1. How does the structure of mosses, liverworts, and hornworts explain their small size? In what...

1. How does the structure of mosses, liverworts, and hornworts explain their small size? In what way does their life cycle still depend on the presence of a water film?

In: Biology

What accounts for the unusual properties of the heart of a shrew? In other words, why...

  1. What accounts for the unusual properties of the heart of a shrew? In other words, why is the shrew’s heart unusually large with an unusually slow heart rate?
  2. What are the three general components of a circulatory system? Describe the functions of a cardiovascular system.
  3. What are the limitations of Diffusion?
  4. Describe the 3 main types of pumping structures in animal circulatory systems?
  5. Distinguish between open and closed circulatory systems. Is the distinction between open and closed circulatory systems always clear? Distinguish among interstitial fluids, blood, lymph, and hemolymph.
  6. Compare and contrast hemocytes found in insects and vertebrates.
  7. Describe composition and functions of plasma?
  8. Describe functions of the five types of leukocytes?
  9. Describe the structure and function of erythrocytes?
  10. Describe the structure and function of platelets?
  11. How do sponges, cnidarians, and flatworms manage without a circulatory system?
  12. Describe the circulatory system of an oligochaete?
  13. Compare and contrast the circulatory system of a bivalve and a cephalopod?
  14. Compare and contrast the structure and function of the circulatory systems of a branchiopod crustacean and a decapod crustacean?
  15. Describe the five common features of crustacean heart?
  16. How is the hear of Daphnia magnus different than the typical crustacean heart?
  17. Describe the structure and function of the insect circulatory system.
  18. Do all animals have a circulatory system? (explain)
  19. Closed circulatory systems are usually found in high active organisms with high demands for oxygen or in those living in oxygen limited environments. What is the main exception to this general rule? (explain)

In: Biology

What is the relationship between the Reproductive Rate (R0) and the proportion of susceptible individuals that...

What is the relationship between the Reproductive Rate (R0) and the proportion of susceptible individuals that become infected with a disease? Is there a value below which almost no one becomes infected?

In: Biology

Industrial Melanism The peppered moth, Biston betularia, is a speckled moth that rests on tree trunks...

Industrial Melanism

The peppered moth, Biston betularia, is a speckled moth that rests on tree trunks during the day, where it avoids predation by blending with the bark of trees (an example of cryptic coloration). At the turn of the century, moth collectors in Great Britain collected primarily light forms of this moth (light with dark speckles) and only occasionally recorded rare dark forms. With the advent of the Industrial Revolution and increased pollution, light-colored lichens on the trees died, resulting in strong positive selection for dark moths resting on the now dark bark. The dark moth increased in frequency. However, in unpolluted regions, the light moth continued to occur in high frequencies. (This is an example of the relative nature of selective advantage, depending on the environment.)

Color is controlled by a single gene with two allelic forms, dark and light.   Pigment production is completely dominant, and the lack of pigment is recessive.   We use the letters A and a for these alleles.

  1. If this population met the assumptions for Hardy Weinberg Equilibrium predict the genotypic frequencies for the next generation.
  2. Now, assume that pollution has become a significant factor and that in this new population 50% of the light moths but only 10% of the dark moths are eaten (natural selection). How many moths would be left for each phenotype? What would be the p and q values of the population after predation? (Assume both genotypes for the dominant phenotype are eaten equally)

In: Biology

Compare and contrast N-fixation and mycorrhizal associations. Your answer should include the organisms involved and the...

Compare and contrast N-fixation and mycorrhizal associations. Your answer should include the organisms involved and the major role they play.

In: Biology

You are interested in how weight of brazil nuts was shown to be under the control...

  1. You are interested in how weight of brazil nuts was shown to be under the control of two genes. Each locus can be occupied by either an additive or non-additive allele, and the effect of each additive allele on nut weight is approximately equal. In a population study, two true-breeding strains were isolated. The nuts from one of the strains weighed 10.0 g and the nuts from the other strain weighed 15.0 g. Assuming, that these strains represent the upper and lower limits of nut weight, answer the following questions.

a. If the two strains are crossed, what would be the weight of the nuts produced by the F1 plants? Explain your answer

b. If two F1 plants are crossed, what range and distribution of nut weight would you expect to see among 64, F2 progeny? Be sure to list the classes and the # of additive alleles for each class, as well as the predicted # of individuals in each class

In: Biology

What is the function of the cytoskeleton in eukaryotic cells? multiple can be selected Move chromosomes...

What is the function of the cytoskeleton in eukaryotic cells?

multiple can be selected

Move chromosomes during cell division

Maintain cell shape by resisting tension

Anchor the nucleus and some other organelles

Divide animal cells in two

In: Biology

Which of the following processes is most likely to play a critical role in generating antibodies...

Which of the following processes is most likely to play a critical role in generating antibodies that effectively combat fungal infections?

Group of answer choices:

A.Fc receptors

B.Allelic exclusion

C.T cell help

D.Apoptosis

E.Use of the kappa (k) light chain

In: Biology

In humans (and most animals), sex is determined using the X-Y system. The basis of this...

In humans (and most animals), sex is determined using the X-Y system. The basis of this system is that the number of X chromosomes and Y chromosomes determines whether the individual will be male or female. A male will contain one X and one Y chromosome, while a female will contain two X chromosomes.

For this discussion, consider how the number of X chromosomes affects the inheritance of traits that are carried on the X chromosome. Does this make one sex more likely to display certain characteristics? Why or why not?

  • Clearly explain how the number of alleles for sex-linked genes varies in males and females.
  • Include how this affects the genotypes of each sex. In other words, are these terms applicable: homozygous, heterozygous, carriers, etc.?
  • Considering a recessive genetic disorder that is carried on the X-chromosome, should a male child be more concerned if his mother has the disorder or his father has the disorder? Explain your reasoning. How might this differ for a female child?

In: Biology

1)Explain the principles of RAPD and rep PCR genotypic fingerprinting. 2)what are the different criteria used...

1)Explain the principles of RAPD and rep PCR genotypic fingerprinting. 2)what are the different criteria used for naming bacterial species.

3)Illustrate how the ribosomal genes and ITS regions are present in the genome of bacteria and fungi 4).Explain how you would use sequences of genes or regions of the genome to identify microorganisms. 5)Why is 16 SrRNA gene an excellent molecular(chronometer).6)What is the minimum similarity level for a bacterial species and a bacterial genus based on 16S rRNA gene sequences.7)Why is 16S-23S ITS sequences more discriminatory at sub genus and sub species levels of bacterial taxa than 16S rRDNA sequencing.8)Can bacterial genera and species be named based on 16 S-23ITS gene sequences.9)What are the major database used for comparing 16S rRNA gene sequences.10)What are the problems with the present nomenclature of bacteria as it relates to identification of bacteria by 16 SrDNA gene sequences.11)How did 16 rRNA gene sequencing identification contributed to clinal microbiology.12)Explain how bacteriophage typing can be used to identify bacteria.13)What is FAME and how is it used to identify microorganisms.14)Explain how BIOLOG system is used to identify microorganisms. 15)What is IMViC.What is the typical IMVic pattern for E.coli.16) name the different types of vaccine.Explain how they are produced.17)explain the function of dendritic,macrophages,Th1 and Th2 lymphocytes, B lymphocytes.18)what is the role of acidity,complement system(enzymes)normal microbial flora in the innate defense system

In: Biology

What is the difference between the lytic and lysogenic stage of reproduction in viruses? Why can...

What is the difference between the lytic and lysogenic stage of reproduction in viruses? Why can some pathogenic viruses remain in an infected person for long periods of time?

In: Biology

How is the genetic code used in gene expression?

  1. How is the genetic code used in gene expression?

In: Biology

Consider the emergence of a pandemic, from the first spillover event to worldwide transmission. Where are...

Consider the emergence of a pandemic, from the first spillover event to worldwide transmission. Where are the points at which we could stop the spread of the disease? Explain.

In: Biology

A patient in the hospital has an intravenous catheter inserted to allow for the delivery of...

A patient in the hospital has an intravenous catheter inserted to allow for the delivery of medications, fluids, and electrolytes. Four days after the catheter is inserted, the patient develops a fever and an infection in the skin around the catheter. Blood cultures reveal that the patient has a blood-borne infection. Tests in the clinical laboratory identify the blood-borne pathogen as Staphylococcus epidermidis, and antibiotic susceptibility tests are performed to provide doctors with essential information for selecting the best drug for treatment of the infection. Antibacterial chemotherapy is initiated and delivered through the intravenous catheter that was originally inserted into the patient. Within 7 days, the skin infection is gone, blood cultures are negative for S. epidermidis, and the antibacterial chemotherapy is discontinued. However, 2 days after discontinuing the antibacterial chemotherapy, the patient develops another fever and skin infection and the blood cultures are positive for the same strain of S. epidermidis that had been isolated the previous week. This time, doctors remove the intravenous catheter and administer oral antibiotics, which successfully treat both the skin and blood-borne infection caused by S. epidermidis. Furthermore, the infection does not return after discontinuing the oral antibacterial chemotherapy. What are some possible reasons why intravenous chemotherapy failed to completely cure the patient despite laboratory tests showing the bacterial strain was susceptible to the prescribed antibiotic? Why might the second round of antibiotic therapy have been more successful? Justify your answers.

In: Biology

Draw the generalized alternation of generations life cycle all plants follow. When are plants gametophytes? Sporophytes?...

  1. Draw the generalized alternation of generations life cycle all plants follow. When are plants gametophytes? Sporophytes? Know this for bryophytes (mosses), seedless vascular plants (ferns), gymnosperms and angiosperms for the exam.

In: Biology