1. What lines of reasoning support the hypothesis that the first self-replicating systems were based on RNA molecules?
2. Why is the origin of cyanobacteria a critical step in evolution?
3. What evidence supports the idea that mitochondria and chloroplasts were once free-living members of the domain bacteria?

4. What evidence supports the classification of life into three domains?

5. Compare and contrast the physical and chemical conditions on Earth at the time life first arose with conditions today.
   a) Discuss two reasons why animals could not have existed on early Earth.
   b) In what ways has microbial metabolism altered Earth’s biosphere?
   c) How might life on Earth be different if oxygenic photosynthesis had not evolved?

Spiders have what kind of circulation?

A. Closed circulation with blood vessels

B. Intermediate circulation with some vessels and some areas where the fluid moves directly around tissues

C. Open circulation with fluid bathing all organs and tissues

D. None of the above

Consider 2 alleles in a population of seahorses: A and a. There are 2 sea horses with genotype AA, 96 seahorses with genotype Aa and 2 seahorses with genotype aa. What are the frequencies of the alleles in this population. Please show all work. Is this population in the Hardy Weinberg Equilibrium? Explain why or why not. THANKS IN ADVANCE!! :)

You are doing rotation in hospital's clinical laboratory. A sample of cloudy cerebrospinal fluid (CSF) from suspected meningitis case arrives and you are told to gram stain it and then plate it on blood agar and chocolate agar. In gram stain you find gram negative bacilli of varying size and shape. You also find lot of bacteria inside phagocytic cells. They are not diplococci.

Later charge nurse tell you the patient, a 3 year old girl, has not received any childhood vaccinations.

1. what is most likely causative agent .How do you know?

2.Explain your results on blood and chocolate agar.

3. Why is the fact that agent is not diplococci significant.

4. Give background info on the causative agent. Also explain what is causing the cloudiness in the CSF fluid.

5. Is this type of infection most often accompanied by increased PMNs, or increased lymphocytes. Explain.

6. Give detailed info about your choice organism: microbial characteristic, nutritional requirements, and growth characteristics(i.e facultative anaerobe, acidophile, capsule forming, lophotrichous flagella..)

In chickens, comp shape is determined by alleles at two loci (R, r and P, p). A walnut comb is produced when at least one dominant allele R is present at one locus, at least one dominant P allele is present at the second locus (i.e. genotype R_P_). A rose comb is produced when at least one dominant allele is present at the first locus and two recessive alleles are present at the second locus (genotype R_pp). A pea comb is produced when two recessive alleles are present at the first locus, and at least one dominant allele is present at the second (genotype rr P_). If two recessive alleles are present at the first and the second locus (rrpp), a single comb is produced. Progeny with what types of combs and in what proportions will result from the following crosses?

a. RR PP x rr pp

b. Rr Pp x rr pp

c. Rr Pp x Rr Pp

d. Rr pp x Rr pp

e. Rr pp x rr Pp

f. Rr pp x rr pp

please show step by step

Bean beetles (Callosobruchus maculatus) are agricultural pest insects of Africa and Asia. Females lay their eggs on the surface of beans (Family Fabaceae). Eggs are deposited singly and several days after deposition, a beetle larva (maggot) burrows into the bean. At 30°C, pupation and emergence of an adult beetle occurs 21–30 days after an egg was deposited. Adults are mature 24–36 hours after emergence and they do not need to feed. Adults may live for 1–2 weeks, during which time mating and oviposition (laying of eggs) occurs. Since larvae cannot move from the bean on which an egg was deposited, the oviposition choice of a female determines the future food resources available to their offspring. As a result, it is the most critical choice a female makes for her offspring, because it will influence their growth, survival, and future reproduction. Although females can be induced to lay eggs on a wide range of bean species, very few bean species result in normal development and the successful emergence of adults.

1. What is the test organism/experimental unit/subject in this experiment?

2. What is/are the dependant variable(s) in this experiment?

3. For a chi-square analysis how many degrees of freedom are present in this study?

About 3 million years ago, the Isthmus of Panama (a narrow strip of land connecting North and South America) formed, dividing marine organisms into Pacific and Caribbean populations. Researchers have examined species of snapping shrimp on both sides of the isthmus. Based on the morphological species concept, there appeared to be seven pairs of closely related species, with one species of each pair in the Pacific and the other in the Caribbean. The different species pairs live at different depths in the ocean. Using mitochondrial DNA sequences, the researchers estimated phylogenies and found that each of these species pairs (sister species), separated by the isthmus, were indeed each other's closest relatives. The researchers investigated mating in the lab and found that many species pairs were not very interested in courting with each other, and, any that did mate, almost never produced fertile offspring.

1. These species are distinctive species under all three species concepts.

a. Likely

b. Not Likely

2. Sympatric speciation caused the difference between the seven species on the Pacific side.

a. Likely

b. Not Likely

3. Sympatric speciation caused the differences between the sets of sister species on either side of the Isthmus.

a. Likely

b. Not likely

4. If sea levels rises enough to cover the isthmus, the sister species on either side of the isthmus will likely undergo fusion.

a. Likely

b. Not likely

5. Habitat isolation is the only reproductive isolating barrier preventing the formation of hybrid from the different sister species.

a. Likely

b. Not likely

6. If sea levels rise enough to cover the isthmus, the frequency of hybrid offspring would decrease.

a. Likely

b. Not likely

7. What other type of reproductive isolating barrier is creating the reinforcement of differences between the sister (closely related) shrimp species pairs?

a. Behavioral isolation

b. Gametic isolation

c. Temporal isolation

d. Reduced hybrid fertility

e. Both A and D

This applies to forensics/fingerprinting

1. For two prints to be made by the same source, the ridge characteristics must be present in both impressions and in the same RELATIVE area. Why relative and not exact?

How can we determine the accuracy of gene expression levels in different databases? How can these variations be minimized?

report on 5 different food additives that you research (be sure to include what information you used for your report.) Tell me things for example, what they come from, why they are used , contraindications, and what potential side effects they may have.

1. About how many species have been given scientific names to date?

a. 100,000

b. 500,000

c. 1 to 2 million

d. over 6 billion

2. Most species live in

a. the air surrounding the earth

b. the ocean

c. temperate zones

d. tropical regions

3. Which of the following statements is true of most ancient species? They

a. are still surviving today

b. are living in dormant states

c. died leaving behind fossils

d. became extinct without leaving fossils

4. “Naming, describing and classifying organisms into different categories based on their characteristics” is a definition of

a. taxonomy

b. natural selection

c. biology

d. morphology

5. Which of the following is the most specific level of classification?

a. Class

b. Genus

c. Order

d. Phylum

6. The great diversity of life was largely caused by

a. Spontaneous mutations

b. Natural selection

c. Taxonomic transformation

d. Genetic manipulation

7. The system of biological classification used today was created by

a. Aristotle

b. Carolus Linnaeus

c. Charles Darwin

d. Stephen Jay Gould

8. The organisms with the greatest number of species are

a. Insects

b. Rodents

c. Single celled bacteria

d. Vertebrates

9. Which of the following is the correct format for binomial nomenclature?

a. Homo Sapiens

b. Homo sapiens

c. Homo sapiens

d. homo sapiens

10. Which of the following is the broadest classification category of living things?

a. Family

b. Genus

c. Phylum

d. Species

11. A population of organisms that can reproduce fertile offspring is a

a. Family

b. Genus

c. Kingdom

d. Species

12. In which phylum do humans belong?

a. Chordates

b. Invertebrates

c. Primates

d. Prokaryotes

13. The use of two names as the scientific name for an organism is called

a. Binomial nomenclature

b. Biotaxonomy

c. Darwinian classification

d. Dewey system

14. The main purpose of using the Linnaean classification system is to be able to

a. Trace the evolution of different species

b. Count all living organisms past and present

c. Group organisms with others with similar characteristics

d. Organize organisms from most simple to most complex

15. The Linnaean classification system is most like

a. A library catalogue system

b. Google’s search engine

c. The index of a book

d. Telephone area codes

16. Which of the following is a characteristic shared by all living organisms? They

a. Reproduce sexually

b. Develop spores for protection

c. Begin life as a single cell

d. Maintain a constant body temperature

17. Which of the following differentiates living things from non-living things?

a. The presence of carbon

b. Chemical activity

c. Growth and development

d. Motility

Answer each of the following questions as true or false:

18. Living organisms regulate their use of energy.

19. All species in the animal kingdom obtain energy by ingesting other living things.

20. All mammals are primates.

21. The sum of all the energy used by living organisms is called anabolism.

22. Living things may remain dormant for many years.

23. Diversity is an important contributor to a sustainable ecosystem.

24. Most species have been identified and given a scientific name.

25. Homeostasis is dependent on positive feedback mechanisms.

Is each of the following mutations a transition, a transversion, an addition, or a deletion? The original DNA strand is 5′-GGACTAGATAC-3 ′ (Only the encoded DNA strand is shown.)

A. 5′-GAACTAGATAC-3 ′ B. 5′-GGACTAGAGAC-3 ′ C. 5′-GGACTAGTAC-3 ′ D. 5′-GGAGTAGATAC-3 ′

What modifications were made to adjust for life on land ? Briefly explain at least 3 modifications.