BIOL 101: CH. 1 HW
Which of the following statements demonstrates unity in the diversity of life?
***All of the listed statements are correct. -All organisms, including prokaryotes and eukaryotes, use essentially the same genetic code. -The forelimbs of all mammals have the same basic structure, modified for different environments =Cilia and flagella in all eukaryotes have the same basic structure. -The structure of DNA is the same in all organisms.
After completing all experiments, rank the following control groups and treatment groups from least effective to most effective at decreasing bacterial diversity. Rank the groups from least effective to most effective. Two groups may be ranked equivalently.
LEAST -Control: unwashed hands -Control: rubbing hands with water -Treatment: rubbing hands with hand sanitizer -Treatment: rubbing hands with hand soap MOST
What are the characteristics of a good hypothesis?
-A good hypothesis leads to repeatable experiments -A good hypothesis is falsifiable. -A good hypothesis is testable.
What are the components of a good scientific question?
-The question is testable. -The question will lead to measurable data. -The question is specific.
Can you pick out the mossy leaf-tailed gecko lying against the tree trunk in this photo? How is the appearance of the gecko a benefit in terms of survival? Select the two correct statements.
-This coloration likely makes it easier for the gecko to hunt insects. -This coloration likely makes it harder for the gecko to be seen by predators.
Given what you learned about evolution, natural selection, and genetic information, describe how the gecko's coloration might have evolved. Rank the stages from earliest to oldest.
1. There are geckos of different coloration in a population. 2. Geckos that more closely resemble their background are less visible to predators and are more likely to survive, reproduce, and leave offspring. 3. The offspring would inherit the genes that generated the mossy bark coloration. 4. Over the generations, the coloration would become a closer and closer maich to the tree bark
How many dark brown mice were caught in the dark-colored soil enclosure on a moonlit night?
12
Now take a look at the data on both graphs for light brown mice, shown as white bars on the graphs. How many light brown mice were caught in the light-colored soil enclosure on a moonlit night?
18
How many dark brown mice were caught in the light-colored soil enclosure on a moonlit night?
19
How many light brown mice were caught in the dark-colored soil enclosure on a moonlit night?
28
If the results of this study prove correct, taking a fish oil supplement is most likely to benefit which of the following type of person?
A person with an increased risk of heart attack.
What is the difference between a hypothesis and a prediction?
A prediction is an "If . . . then" statement specific to an experiment, and a hypothesis is a possible explanation of an observation.
Suppose that Zonosemata flies whose own wings had been clipped and reattached were attacked more frequently than untreated Zonosemata flies. How would this result have affected the reliability of the other experimental results?
All results for the experimental groups involving wing surgery would be invalid.
A group of bioterrorists wants to make use of the H5N1 virus. Which of the following will they need to do to the virus to wreak havoc on humans?
Alter it so that person-to-person transmission is possible.
What sorts of functions might these shared genes have?
Coding for ribosomal RNA
Which condition is optimal for predation by the owl on mice?
Dark nights are better for hunting.
The mRNA vaccine available for Covid-19 utilized Crispr technology. What was done?
Gene editing was performed. Submit
Based on the results of the lab, fill in the following sentences. Place the terms in the appropriate blanks to complete the sentences. Terms may be used once, more than once, or not at all.
Hand soap reduces bacterial diversity Hand sanitizer reduces bacterial diversity. Neither hand soap nor hand sanitizer is superior at reducing bacterial diversity.
As you learned in the lab, a t-test produces a test statistic called a p-value. Can you fill in the statements below about how p-values are used to accept or reject hypotheses? Place the terms in the appropriate blanks to complete the sentences. Terms may be used more than once.
If the p-value is greater than or equal to 0.05, the null hypothesis is ACCEPTED and an alternative hypothesis is REJECTED If the p-value is less than 0.05, the null hypothesis is REJECTED and an alternative hypothesis is ACCEPTED Data analysis from an experiment yielded a p-value of 0.3. Consequently, the scientists ACCEPTED the null hypothesis and REJECTED an alternative hypothesis.
Which of the following is true of a scientific theory?
It generates testable hypotheses, is supported by a large body of evidence, and is broad in scope.
Complete the description of how to test the hypothesis. Match the terms in the left column to the appropriate blanks in the sentences on the right. Not all terms will be used.
It might be possible to do a LONG-term study in an area where you excluded predators. Mice have SHORT generation times, so if predation is "naturally selecting" lighter colored mice, then in the absence of predation you might predict the fur color WOULD NOT remain predominantly LIGHT in such an experimental population.
Sort the following results by their p-values, choosing whether the null hypothesis should be accepted or rejected in favor of an alternative hypothesis. Sort each item to the appropriate bin.
Null rejected in favor of alt hypothesis: -hand sanitizer does not affect bacterial diversity P < 0.001 -soap does not affect bacterial diversity P < 0.001 Null accepted: -hand soap and hand sanitizer equally decrease bacterial diversity p= .40
On a moonlit night, would a light brown mouse be more likely to escape predation by owls on dark- or light-colored soil? What data support your conclusion?
On light-colored soil; fewer light brown mice were caught on light soil than on dark soil under a full moon.
Determine whether the following statements about null and alternative hypotheses are true or false. Place "True" or "False" at the end of each statement.
TRUE: A null hypothesis states that there is no relationship between the independent and dependent variables. TRUE: Alternative hypotheses infer an effect between two variables. TRUE: There can be multiple alternative hypotheses. FALSE: There can be multiple null hypotheses.
In an experiment, investigators try to control all of the variables except one—the one that tests the hypothesis. Which of the following reasons is the primary rationale for controlling variables in an experiment?
To eliminate alternative explanations for the results of an experiment
In Pasteur's experiment to test the hypothesis of spontaneous generation, why did he boil the broth in both flasks?
To kill any existing organisms in the broth
Is a dark brown mouse on dark-colored soil more likely to escape predation under a full moon or with no moon? What data support your answer?
Under a full moon; the owl caught more dark mice when there was no moon (about 20) than when there was a full moon (about 12).
Is a light brown mouse on light-colored soil more likely to escape predation under a full moon or with no moon? What data support your answer?
Under no moon; the owl caught more light mice when there was a full moon (about 18) than when there was no moon (about 11).
Why is milk often fortified with Vitamin D?
Vitamin D is associated with calcium uptake.
Based on the results of the mouse coloration case study, suggest another hypothesis researchers might use to study the role of predators in natural selection.
You might wonder what would happen if a population of beach mice lived in an area where predators were absent.
What combination of independent variables led to the highest predation level in enclosures with dark-colored soil?
light brown coat with full moon
Now think about the data from the viewpoint of the owl's hunting success. Combining the data shown in both graphs, estimate the total number of mice caught in moonlight versus no-moonlight conditions.
moonlight: about 77 caught; no moonlight: about 95 caught
Under which conditions would a dark brown mouse be most likely to escape predation at night?
on dark-colored soil with full moon light
Under which conditions would a light brown mouse be most likely to escape predation at night?
on light-colored soil with no moon
Competition is central to the theory of natural selection. Why does competition occur?
organisms typically produce too many offspring and resources are limited
What is the dependent variable, the response to the variables being tested?
the number of mice caught
Which of the following statements is true of a hypothesis?
A hypothesis can be supported or rejected through experimentation.
You have your blood tested. The results show that you have adequate levels of Vitamin D. Which of the following would likely be best for you?
Not take a Vitamin D supplement.
Drag each statement under the step in the scientific method that it demonstrates.
Observation: The eggs of mice in plastic cages washed with harsh soap displayed problems during cell division that caused genetic abnormalities. Question: Could bisphenol A from the plastic be affecting the mice in the damaged cages? Hypothesis: The frequency of genetic abnormalities in mice is affected by exposure to bisphenol A Prediction: If mice are exposed to elevated levels of bisphenol A, the frequency of genetic abnormalities in these mice will increase.
Drag the labels to identify the components of Hunt's experiment. Labels may be used once, more than once, or not at all.
Observation: The eggs of mice in plastic cages washed with harsh soap displayed problems during cells division that caused genetic abnormalities Question: Could bisphenol A from the plastic be affecting the mice in the damaged cages Hypothesis: The frequency of genetic abnormalities in mice is affected by exposure to bisphenol A Prediction: If mice are exposed to elevated levels of bisphenol A the frequency of genetic abnormalities in these mice with increase
Suppose the sub-hypothesis that wing waving alone reduces predation by jumping spiders was supported by the Zonosemata experiment. What results would have supported that sub-hypothesis?
Zonosemata flies with housefly wings are attacked less frequently
So far you've looked at each color of mice separately. Next, consider the two colors of mice together when looking at the graphs. What combination of independent variables led to the highest predation level in enclosures with light-colored soil?
dark brown coat with no moon
Sort the following phrases based on whether they apply to the experimental group or the control group in an experiment. Sort each item to the appropriate bin.
experimental group: -the group that receives the treatment while all other variables are kept constant -used to measure the effect of hand soap on bacterial diversity -used to measure the effect of hand sanitizer on bacterial diversity Control group -used to establish a baseline for comparison -used to measure the bacterial diversity of unwashed hands -the group that does not receive treatment while all other variables are kept constant
The graph shows data from the light-colored soil enclosure. There is one dependent variable and more than one independent variable on the graph. What are the independent variables, the variables that were manipulated by the researcher?
mouse coat color and the presence or absence of moonlight
You are a historian writing a book about diseases that affected United States history. Which of the following diseases had the largest impact?
smallpox
Excited about the fungus chemical's promise for treating cancer, you write up your experimental results and send the paper to a prestigious scientific journal, hoping it will be published. The journal sends your paper out to several scientists for evaluation--a process known as peer review.The reviewers identify several issues with the experimental design and data presented in your paper. Which of the following criticisms are valid issues of concern that peer reviewers might identify?
- The effect may not be real because we don't know if the results are reproducible. - The treatment kills cancer cells, but it might simply be a poison that kills all cells—even normal cells. - Cell samples were taken from too few patients
Using the hypothetical petri dishes below, calculate the difference in bacterial diversity between the before and after samples. In these hypothetical samples, different sizes and shapes of colonies represent different bacterial species. Colonies of the same size and shape represent the same species.
-3 Species
Drag type of experiment on the left to the example of experiment on the right.
1. natural: Blood concentrations of BPA in college students are compared to their recent consumption of canned food 2. natural: The feeding behavior of fish in streams that receive acidic runoff from strip mines is compared to the feeding behavior of fish in unaffected streams. 3. natural: The deformity rate in baby birds from nests in pesticide-sprayed fields is compared to the deformity rate in birds from nests in unsprayed fields. 4. manipulative: Tumor development is compared in mice exposed to five dosages of a known carcinogen in the laboratory. 5. manipulative: Foraging activity levels are compared in tadpoles exposed to four concentrations of toxic metals in the laboratory. 6. manipulative: Growth of corn plants is compared in field plots sprayed with three different dosages of weed killer. 7. natural : BPA concentrations in the urine of people with diabetes are compared to BPA concentrations in the urine of people without diabetes.
You are a family practitioner. Which of the following patients you see is most likely to need Vitamin D supplements?
A woman with dark brown skin who lives in Michigan.
Compose a biological hierarchy for a coral reef as the ecosystem, a fish as the organism, its stomach as the organ, and DNA as the molecule. Include all levels in the hierarchy and start from the higher level of biological organization. Drag the appropriate labels to their respective targets
Biosphere ➡️ ecosystem ➡️ community➡️ population ➡️ organism ➡️ organ ➡️ tissue ➡️ cell ➡️ organelle ➡️ molecule
Hunt and her team designed an experiment to test her hypothesis about the effect of BPA on mice. They administered daily doses of BPA to groups of female mice over three, five, or seven days and then tested these mice for genetic abnormalities that occur during meiosis, the division of chromosomes during egg formation. Drag the labels to identify the components of Hunt's experiment. Labels may be used once, more than once, or not at all.
Dosage 0: control Dosage 20: treatment Dosage 40: treatment Dosage 60: treatment Dosage: independent Time: independent % abnormalities: dependent
Make sure you understand the difference between independent and dependent variables. Two of the following phrases are general descriptions of these variables. Three phrases are specific to an experiment you conducted in the lab. Sort each item to the appropriate bin.
Independent variable A factor in an experiment whose value is manipulated or changed to reveal possible effects on another factor Use of hand sanitizer Use of hand soar Dependent variable - Amount of bacterial diversity -A factor in an eyneriment whose value Is measured to see whether it IS influenced by changes in another factor
The bars on the graphs show the numbers of mice that were caught, but keep in mind that mice that were not caught by the owl escaped predation. On a moonlit night, would a dark brown mouse be more likely to escape predation by owls on dark- or light-colored soil? What data support your conclusion?
On dark-colored soil; fewer dark brown mice were caught on dark soil than on light soil under a full moon.
You are a registered dietician. Which of the following clients is most likely to benefit from taking a fish oil supplement?
Someone who rarely eats fish.
Covid-19 is a truly global pandemic. Which of the following was most like it in distribution around the planet?
Spanish influenza
Based on your hypothesis, you predict that the chemical isolated from the fungus will successfully kill cancer cells. To test this prediction, you design the following experiment. - You isolate cancerous cells from the colon of a patient from North Carolina and culture (grow) the cells in your lab. - You divide the cultured cells into four separate culture dishes. You treat two of the dishes with the fungus chemical and the other two with a control solution that does not contain the chemical. -Over the next ten days, you collect data on the percentage of cells that remain alive in each culture dish.
Supported -Cancer cells treated with the chemical have a lower survival rate than cells that are not tested -After 5 days of chemical treatment, less than 50% of the cancer cells are alive
Which of the following statements could not be supported or rejected by a scientific experiment?
The first living cell on Earth came from outer space
If trends continue, which of the following will happen?
The number of diseases crossing from animals to humans will increase.
Which of the following variables did Pasteur change in his experiment to test the hypothesis of spontaneous generation?
The shape of the flask
A typical prokaryotic cell has about 3,000 genes in its DNA, while a human cell has about 21,300 genes. About 1,000 of these genes are present in both types of cells. How do you explain how such different organisms could have this same subset of 1,000 genes?
The subset of genes shared by humans and prokaryotes originates from a common ancestor and has been retained over billions of years of evolution.
Which of the following statements is not true of scientific experiments?
They must occur under carefully controlled conditions found in a laboratory.
The reviewers suggested that you think more carefully about your hypothesis and experimental design. For a chemical to make a good cancer treatment, it is not enough that it harms cancer cells. The chemical needs to have a selective effect on cancer cells--that is, it needs to harm cancer cells much more than it harms normal (noncancerous) cells.You decide to run a new experiment to test the hypothesis that the fungus chemical harms cancer cells selectively. In this controlled experiment, you will test both cancer cells and normal cells under identical conditions. What data would support this hypothesis? Predict the expected results for cancer cells and normal cells by choosing the correct graph lines and dragging them onto the two graphs.
graph 1 should show a decrease in cancer cells graph 2 should show little to no change
Based on both graphs, what condition(s) are most deadly for both colors of mice?
high contrast between the mouse and its background