ACT Science : How to find research summary in biology

Study concepts, example questions & explanations for ACT Science

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Example Questions

Example Question #207 : Biology

The process by which cells divide and multiply is known as the cell cycle. This cycle consist of two main phases: interphase and mitosis. Each phase consists of a series of clearly defined and observable steps. At the conclusion of the cycle, each parent cell produces two genetically identical daughter cells that may undergo a cycle of replication.

Roughly 90 percent of the cell cycle is spent in interphase. Interphase is comprised of three main steps: the first gap phase, the synthesis phase, and the second gap phase. The initial gap phase is a period of cellular preparation in which the cell increases in size and readies itself for DNA synthesis. In the synthesis phase, DNA replication occurs. In the second gap phase the cell grows in size and prepares for cellular division in the mitotic phase. At the end of each gap phase the cell has to pass regulatory checkpoints to ensure proper cell growth and environmental conditions.

Mitosis is a form of nuclear division and is broken down into five distinct phases. During prophase, the genetic material contained in chromatin condenses into distinct chromosomes. Prometaphase is marked by the breakdown of the nuclear envelope and the formation of centrosomes at the poles of the cell. During metaphase, kinetochores attached to the microtubules migrate the chromosomes to the center of the cell. A checkpoint ensures that the chromosomes are aligned on the center and halts the cycle if an error occurs. Anaphase occurs when chromosomes break apart at their center or centromere and sister chromatids move to opposite ends of the cell. Last, telophase and cytokinesis occurs as nuclear membranes form in each new daughter cell and when chromosomes unwind into loose chromatin. Cytokinesis is defined as the division of the each cell’s cytoplasm and organelles. The conclusion of the cell cycle results in the production of two genetically identical daughter cells.

Ninety percent of the cell cycle is spent in which stage?

Possible Answers:

Anaphase

Gap 1

Prophase

Interphase

Correct answer:

Interphase

Explanation:

Interphas

The passage clearly states that 90 percent of ths cell cycle is spent in interphase. Interphase is a period of cellular preparation in which the cell grows and ensures environmental conditions are proper for cellular division.

 

Example Question #201 : Act Science

The process by which cells divide and multiply is known as the cell cycle. This cycle consist of two main phases: interphase and mitosis. Each phase consists of a series of clearly defined and observable steps. At the conclusion of the cycle, each parent cell produces two genetically identical daughter cells that may undergo a cycle of replication.

Roughly 90 percent of the cell cycle is spent in interphase. Interphase is comprised of three main steps: the first gap phase, the synthesis phase, and the second gap phase. The initial gap phase is a period of cellular preparation in which the cell increases in size and readies itself for DNA synthesis. In the synthesis phase, DNA replication occurs. In the second gap phase the cell grows in size and prepares for cellular division in the mitotic phase. At the end of each gap phase the cell has to pass regulatory checkpoints to ensure proper cell growth and environmental conditions.

Mitosis is a form of nuclear division and is broken down into five distinct phases. During prophase, the genetic material contained in chromatin condenses into distinct chromosomes. Prometaphase is marked by the breakdown of the nuclear envelope and the formation of centrosomes at the poles of the cell. During metaphase, kinetochores attached to the microtubules migrate the chromosomes to the center of the cell. A checkpoint ensures that the chromosomes are aligned on the center and halts the cycle if an error occurs. Anaphase occurs when chromosomes break apart at their center or centromere and sister chromatids move to opposite ends of the cell. Last, telophase and cytokinesis occurs as nuclear membranes form in each new daughter cell and when chromosomes unwind into loose chromatin. Cytokinesis is defined as the division of the each cell’s cytoplasm and organelles. The conclusion of the cell cycle results in the production of two genetically identical daughter cells.

What happens to the cell during the gap phases of interphase?

Possible Answers:

The cell grows and prepares for division.

Sister chromatids migrate to opposite ends of the cell.

Chromosomes line up on the center of the cell.

The cytoplasm is divided equally as the daughter cells separate from one another.

Correct answer:

The cell grows and prepares for division.

Explanation:

The cell grows and prepares for division.

The first and second gap phases provide time for cellular growth and preparation. The cell increases the amount of cytoplasm and organelles within itself to supply enough essentials to support two daughter cells. The passage supports this fact. The other answers are incorrect because they correspond to different phases within the cycle.

Example Question #202 : Act Science

The process by which cells divide and multiply is known as the cell cycle. This cycle consist of two main phases: interphase and mitosis. Each phase consists of a series of clearly defined and observable steps. At the conclusion of the cycle, each parent cell produces two genetically identical daughter cells that may undergo a cycle of replication.

Roughly 90 percent of the cell cycle is spent in interphase. Interphase is comprised of three main steps: the first gap phase, the synthesis phase, and the second gap phase. The initial gap phase is a period of cellular preparation in which the cell increases in size and readies itself for DNA synthesis. In the synthesis phase, DNA replication occurs. In the second gap phase the cell grows in size and prepares for cellular division in the mitotic phase. At the end of each gap phase the cell has to pass regulatory checkpoints to ensure proper cell growth and environmental conditions.

Mitosis is a form of nuclear division and is broken down into five distinct phases. During prophase, the genetic material contained in chromatin condenses into distinct chromosomes. Prometaphase is marked by the breakdown of the nuclear envelope and the formation of centrosomes at the poles of the cell. During metaphase, kinetochores attached to the microtubules migrate the chromosomes to the center of the cell. A checkpoint ensures that the chromosomes are aligned on the center and halts the cycle if an error occurs. Anaphase occurs when chromosomes break apart at their center or centromere and sister chromatids move to opposite ends of the cell. Last, telophase and cytokinesis occurs as nuclear membranes form in each new daughter cell and when chromosomes unwind into loose chromatin. Cytokinesis is defined as the division of the each cell’s cytoplasm and organelles. The conclusion of the cell cycle results in the production of two genetically identical daughter cells.

How many checkpoints are present in the cell cycle?

Possible Answers:

1

5

2

3

Correct answer:

3

Explanation:

3

The passage states that there are two checkpoints in interphase and one in mitosis. There are a total of three checkpoints that can halt the cell cycle and prevent cellular division. This information is supported by the passage.

Example Question #210 : Biology

The process by which cells divide and multiply is known as the cell cycle. This cycle consist of two main phases: interphase and mitosis. Each phase consists of a series of clearly defined and observable steps. At the conclusion of the cycle, each parent cell produces two genetically identical daughter cells that may undergo a cycle of replication.

Roughly 90 percent of the cell cycle is spent in interphase. Interphase is comprised of three main steps: the first gap phase, the synthesis phase, and the second gap phase. The initial gap phase is a period of cellular preparation in which the cell increases in size and readies itself for DNA synthesis. In the synthesis phase, DNA replication occurs. In the second gap phase the cell grows in size and prepares for cellular division in the mitotic phase. At the end of each gap phase the cell has to pass regulatory checkpoints to ensure proper cell growth and environmental conditions.

Mitosis is a form of nuclear division and is broken down into five distinct phases. During prophase, the genetic material contained in chromatin condenses into distinct chromosomes. Prometaphase is marked by the breakdown of the nuclear envelope and the formation of centrosomes at the poles of the cell. During metaphase, kinetochores attached to the microtubules migrate the chromosomes to the center of the cell. A checkpoint ensures that the chromosomes are aligned on the center and halts the cycle if an error occurs. Anaphase occurs when chromosomes break apart at their center or centromere and sister chromatids move to opposite ends of the cell. Last, telophase and cytokinesis occurs as nuclear membranes form in each new daughter cell and when chromosomes unwind into loose chromatin. Cytokinesis is defined as the division of the each cell’s cytoplasm and organelles. The conclusion of the cell cycle results in the production of two genetically identical daughter cells.

Cancer is defined as uncontrolled cellular division that results from the deregulation of the cell cycle. Which phases of the cell cycle are most likely to be subject to errors in regulation that could result in cancerous formations?

Possible Answers:

Gap 1, Prophase, and Cytokinesis

Metaphase, Anaphase, and Telophase

Gap 1, Gap 2, and Metaphase

Gap 1, Gap 2, and Cytokinesis

Correct answer:

Gap 1, Gap 2, and Metaphase

Explanation:

Gap 1, Gap 2, and Metaphase

This is the correct answer because these three phases are the phases that contain regulatory checkpoints. Errors in the ability of a cell to regulate the cell cycle via checkpoints could result in uncontrolled cellular division. This is supported by evidence located in the passage.

Example Question #211 : Act Science

The process by which cells divide and multiply is known as the cell cycle. This cycle consist of two main phases: interphase and mitosis. Each phase consists of a series of clearly defined and observable steps. At the conclusion of the cycle, each parent cell produces two genetically identical daughter cells that may undergo a cycle of replication.

Roughly 90 percent of the cell cycle is spent in interphase. Interphase is comprised of three main steps: the first gap phase, the synthesis phase, and the second gap phase. The initial gap phase is a period of cellular preparation in which the cell increases in size and readies itself for DNA synthesis. In the synthesis phase, DNA replication occurs. In the second gap phase the cell grows in size and prepares for cellular division in the mitotic phase. At the end of each gap phase the cell has to pass regulatory checkpoints to ensure proper cell growth and environmental conditions.

Mitosis is a form of nuclear division and is broken down into five distinct phases. During prophase, the genetic material contained in chromatin condenses into distinct chromosomes. Prometaphase is marked by the breakdown of the nuclear envelope and the formation of centrosomes at the poles of the cell. During metaphase, kinetochores attached to the microtubules migrate the chromosomes to the center of the cell. A checkpoint ensures that the chromosomes are aligned on the center and halts the cycle if an error occurs. Anaphase occurs when chromosomes break apart at their center or centromere and sister chromatids move to opposite ends of the cell. Last, telophase and cytokinesis occurs as nuclear membranes form in each new daughter cell and when chromosomes unwind into loose chromatin. Cytokinesis is defined as the division of the each cell’s cytoplasm and organelles. The conclusion of the cell cycle results in the production of two genetically identical daughter cells.

How many daughter cells are produced during the cell cycle?

Possible Answers:

4 similiar gametes

2 genetically identical daughter cells

4 genetically identical gametes

2 similiar daughter cells

Correct answer:

2 genetically identical daughter cells

Explanation:

2 genetically identical daughter cells

in the third paragraph the passage clearly states that the cell cycle produces two genetically identical daughter cells. The other answers are incorrect because gametes are sex cells and the product of meiosis not mitosis.

Example Question #212 : Act Science

The process by which cells divide and multiply is known as the cell cycle. This cycle consist of two main phases: interphase and mitosis. Each phase consists of a series of clearly defined and observable steps. At the conclusion of the cycle, each parent cell produces two genetically identical daughter cells that may undergo a cycle of replication.

Roughly 90 percent of the cell cycle is spent in interphase. Interphase is comprised of three main steps: the first gap phase, the synthesis phase, and the second gap phase. The initial gap phase is a period of cellular preparation in which the cell increases in size and readies itself for DNA synthesis. In the synthesis phase, DNA replication occurs. In the second gap phase the cell grows in size and prepares for cellular division in the mitotic phase. At the end of each gap phase the cell has to pass regulatory checkpoints to ensure proper cell growth and environmental conditions.

Mitosis is a form of nuclear division and is broken down into five distinct phases. During prophase, the genetic material contained in chromatin condenses into distinct chromosomes. Prometaphase is marked by the breakdown of the nuclear envelope and the formation of centrosomes at the poles of the cell. During metaphase, kinetochores attached to the microtubules migrate the chromosomes to the center of the cell. A checkpoint ensures that the chromosomes are aligned on the center and halts the cycle if an error occurs. Anaphase occurs when chromosomes break apart at their center or centromere and sister chromatids move to opposite ends of the cell. Last, telophase and cytokinesis occurs as nuclear membranes form in each new daughter cell and when chromosomes unwind into loose chromatin. Cytokinesis is defined as the division of the each cell’s cytoplasm and organelles. The conclusion of the cell cycle results in the production of two genetically identical daughter cells.

Study 1

Scientists study the role of the cell cycle in the cells of a growing onion. They investigate the number of cells in each phase of the cycle in two parts of the onion: the fast growing root and the slow growing bulb. They record their observations and calculate the percentage of cells undergoing each phase (See Figure 1 andFigure 2).

 

Root

Figure 1

Bulb

Figure 2

What cellular component moves chromosomes to the center of cells during metaphase?

Possible Answers:

Centromeres

Kinetochores

Chromatin

Sister chromatids

Correct answer:

Kinetochores

Explanation:

Kinetochores

Kinetochores attach to chromosomes at the centromere. These are the components that move chromosomes to the center of the cell during mitosis. In anaphase these chromosomes split into sister chromatids that migrate to the poles of the cells. This is suppported by evidence in the passage.

Example Question #213 : Act Science

The process by which cells divide and multiply is known as the cell cycle. This cycle consist of two main phases: interphase and mitosis. Each phase consists of a series of clearly defined and observable steps. At the conclusion of the cycle, each parent cell produces two genetically identical daughter cells that may undergo a cycle of replication.

Roughly 90 percent of the cell cycle is spent in interphase. Interphase is comprised of three main steps: the first gap phase, the synthesis phase, and the second gap phase. The initial gap phase is a period of cellular preparation in which the cell increases in size and readies itself for DNA synthesis. In the synthesis phase, DNA replication occurs. In the second gap phase the cell grows in size and prepares for cellular division in the mitotic phase. At the end of each gap phase the cell has to pass regulatory checkpoints to ensure proper cell growth and environmental conditions.

Mitosis is a form of nuclear division and is broken down into five distinct phases. During prophase, the genetic material contained in chromatin condenses into distinct chromosomes. Prometaphase is marked by the breakdown of the nuclear envelope and the formation of centrosomes at the poles of the cell. During metaphase, kinetochores attached to the microtubules migrate the chromosomes to the center of the cell. A checkpoint ensures that the chromosomes are aligned on the center and halts the cycle if an error occurs. Anaphase occurs when chromosomes break apart at their center or centromere and sister chromatids move to opposite ends of the cell. Last, telophase and cytokinesis occurs as nuclear membranes form in each new daughter cell and when chromosomes unwind into loose chromatin. Cytokinesis is defined as the division of the each cell’s cytoplasm and organelles. The conclusion of the cell cycle results in the production of two genetically identical daughter cells.

Study 1

Scientists study the role of the cell cycle in the cells of a growing onion. They investigate the number of cells in each phase of the cycle in two parts of the onion: the fast growing root and the slow growing bulb. They record their observations and calculate the percentage of cells undergoing each phase (See Figure 1 andFigure 2).

 

Root

Figure 1

Bulb

Figure 2

Chromosomes can be defined as which of the following?

Possible Answers:

Condensed chromatin

Centrosomes

Organelles

Components of the nuclear envelope

Correct answer:

Condensed chromatin

Explanation:

Condensed chromatin

Chromosomes are best defined as the choice that describes them as condensed chromatin. During prohase chromatin condenses into tightly packed chromosomes that carry genetic materia to each of the daughter cells at the conclusion of mitosis.

Example Question #214 : Act Science

Five experiments are done to test the relative infectiousness of different serotypes of the Influenza A virus when exposed to tissue from different organisms and competition from one another.

When the virus is more infectious, it will result in more detectable antigens.

Antigens are detected via Enzyme-linked immunosorbent assay (ELISA), which elicits a detectable hue of purple whenever antigens are detected. The hue darkens in response to increased detection of antigens according to this qualitative scale:

Very Dark Purple, Dark Purple, Purple, Light Purple, and Very Light Purple

Experiment 1

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were separately centrifuged onto single layers on human cells and viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Dark purple     H5N1: purple

Experiment 2

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were separately centrifuged onto single layers on chicken cells and viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Dark purple     H5N1: Very dark purple

Experiment 3

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were separately centrifuged onto single layers on swine cells and viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Very dark purple     H5N1: Purple

Experiment 4

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were centrifuged together onto single layers of duck cells while viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Very dark purple     H5N1: Very dark Purple

Experiment 5

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were centrifuged together onto equal layers of human, chicken, swine, and duck cells while viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Purple     H5N1: Light Purple

In experiment 5, what is the most likely purpose of sampling all of the serotypes together on the 4 cell types?

Possible Answers:

To test for possible effects of competition between serotypes.

To illicit cross-contamination of cells.

To determine the bounds on the antigen detection resolution.

To get the lightest purple possible.

Correct answer:

To test for possible effects of competition between serotypes.

Explanation:

Since, in consideration of all the other experiments as controls, experiment 5 does give some insight into the possible effects of competition between the three serotypes, it is likely that this was a motive for the experiment.

Example Question #215 : Act Science

Five experiments are done to test the relative infectiousness of different serotypes of the Influenza A virus when exposed to tissue from different organisms and competition from one another.

When the virus is more infectious, it will result in more detectable antigens.

Antigens are detected via Enzyme-linked immunosorbent assay (ELISA), which elicits a detectable hue of purple whenever antigens are detected. The hue darkens in response to increased detection of antigens according to this qualitative scale:

Very Dark Purple, Dark Purple, Purple, Light Purple, and Very Light Purple

Experiment 1

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were separately centrifuged onto single layers on human cells and viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Dark purple     H5N1: purple

Experiment 2

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were separately centrifuged onto single layers on chicken cells and viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Dark purple     H5N1: Very dark purple

Experiment 3

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were separately centrifuged onto single layers on swine cells and viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Very dark purple     H5N1: Purple

Experiment 4

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were centrifuged together onto single layers of duck cells while viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Very dark purple     H5N1: Very dark Purple

Experiment 5

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were centrifuged together onto equal layers of human, chicken, swine, and duck cells while viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Purple     H5N1: Light Purple

What is a likely explanation for experiment 2 and experiment 4 having similar outcomes?

Possible Answers:

The lack of infectiousness of H2N2.

The absence of other serotypes in the sample.

The absence of other cell types in the sample.

The similarities between chicken and duck tissue.

Correct answer:

The similarities between chicken and duck tissue.

Explanation:

Chicken and duck cells both represent avian tissue.

Example Question #216 : Act Science

Five experiments are done to test the relative infectiousness of different serotypes of the Influenza A virus when exposed to tissue from different organisms and competition from one another.

When the virus is more infectious, it will result in more detectable antigens.

Antigens are detected via Enzyme-linked immunosorbent assay (ELISA), which elicits a detectable hue of purple whenever antigens are detected. The hue darkens in response to increased detection of antigens according to this qualitative scale:

Very Dark Purple, Dark Purple, Purple, Light Purple, and Very Light Purple

Experiment 1

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were separately centrifuged onto single layers on human cells and viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Dark purple     H5N1: purple

Experiment 2

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were separately centrifuged onto single layers on chicken cells and viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Dark purple     H5N1: Very dark purple

Experiment 3

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were separately centrifuged onto single layers on swine cells and viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Very dark purple     H5N1: Purple

Experiment 4

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were centrifuged together onto single layers of duck cells while viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Very dark purple     H5N1: Very dark Purple

Experiment 5

Three separate serotypes of Influenza A are used: H1N1, H2N2, and H5N1. Viral samples were centrifuged together onto equal layers of human, chicken, swine, and duck cells while viral activity was identified using ELISA. The results are as follows:

H1N1: Very dark purple    H2N2: Purple     H5N1: Light Purple

Based on the experiments, can it be determined which is (relatively) the most infectious serotype?

Possible Answers:

Yes: H5N1

No

Yes: H1N1

Yes: H2N2

Correct answer:

Yes: H1N1

Explanation:

Yes, H1N1 consistently resulted in a very dark purple (the highest infectiousness rating) where the others occasionally did not.

According to the five experiments, H1N1 is the most infectious.

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