a researcher is studying the response of bacteria to a certain chemical in three experiments the bacteria swim towards the chemical and in one experim

ATI TEAS 7

Science TEAS Practice Test

1. A researcher is studying the response of bacteria to a certain chemical. In three experiments, the bacteria swim towards the chemical, and in one experiment, the bacteria swim away from it. What would be the most appropriate next step for the researcher?

A. Report only the first three experiments.
B. Report all the experiments, but refrain from making any conclusions.
C. Repeat the experiment several more times and apply a statistical analysis to the data.
D. Repeat the experiment, adding a new chemical to determine its effect on the bacteria.

Correct answer: C

Rationale: Repeating the experiment multiple times and applying statistical analysis would help ensure the results are reliable. By doing so, the researcher can validate the observed trends and determine the significance of the bacteria's response to the chemical. This approach would enhance the credibility of the findings and allow for more robust conclusions to be drawn. Reporting only the first three experiments (Choice A) would overlook critical data that could provide a comprehensive understanding of the bacteria's response. Refraining from making any conclusions (Choice B) would not utilize the available data effectively. Adding a new chemical in a repeated experiment (Choice D) would deviate from focusing on analyzing the response to the original chemical, introducing unnecessary variables.

2. Which of the following are the products of anaerobic respiration in humans?

A. Ethyl alcohol and CO2
B. Ethyl alcohol only
C. Lactic acid and CO2
D. Lactic acid only

Correct answer: C

Rationale: During anaerobic respiration in humans, lactic acid and CO2 are produced. Choice A, 'Ethyl alcohol and CO2,' is incorrect because ethyl alcohol is not a product of anaerobic respiration in humans. Choice B, 'Ethyl alcohol only,' is incorrect as ethyl alcohol is not a product of anaerobic respiration in humans. Choice D, 'Lactic acid only,' is incorrect because CO2 is also a product of anaerobic respiration in humans.

3. In an experiment where five tropical plants are kept at varying humidity levels in a greenhouse for three months, while one plant is left outside in normal conditions, with plant height measured weekly, what serves as the control of the experiment?

A. Plant height for each tropical plant
B. The plant left outside in normal conditions
C. Humidity level readings in the greenhouse
D. Amount of time used to study plant height

Correct answer: B

Rationale: The correct answer is B. The plant left outside in normal conditions acts as the control in the experiment. It provides a standard reference point for comparison to assess the impact of the varying humidity levels on the growth of the tropical plants. Choice A is incorrect because it refers to the dependent variable being measured, not the control. Choice C is incorrect as humidity levels in the greenhouse are part of the experimental conditions, not the control. Choice D is incorrect as the time used for studying plant height is a parameter of the experiment and not the control.

4. Centrioles are structures involved in cell division. What is their specific role?

A. Forming the nuclear envelope
B. Replicating DNA
C. Organizing microtubules during cell division
D. Protein synthesis

Correct answer: C

Rationale: Centrioles are involved in organizing microtubules during cell division, specifically in forming the mitotic spindle. The mitotic spindle is crucial for the proper alignment and separation of chromosomes during cell division, ensuring the accurate distribution of genetic material to daughter cells. Choice A, forming the nuclear envelope, is incorrect as centrioles do not have a direct role in this process. Choice B, replicating DNA, is incorrect as centrioles are not involved in DNA replication. Choice D, protein synthesis, is incorrect as centrioles do not play a role in protein synthesis.

5. Which of the following is an example of an organ?

A. Skin
B. Neuron
C. Brainstem
D. DNA

Correct answer: A

Rationale: The correct answer is A, 'Skin.' The skin is the largest organ in the human body and consists of multiple tissue types working together to perform various functions such as protection, sensation, and temperature regulation. Choice B, 'Neuron,' is a specialized cell in the nervous system and not an organ. Choice C, 'Brainstem,' is a part of the central nervous system composed of nerve tissues but is not an organ on its own. Choice D, 'DNA,' is a molecule that carries genetic instructions, not an organ.