Corn seeds are placed in two pots labeled A and B. Both pots receive 50g of the same soil, they receive the same amount of light and water each day. A chemical called colchicines is mixed with soil of plant B. Plants are allowed to germinate (grow). Slides are made from the roots of both plants A and B. Mitosis of plant A seems normal, but plant B shows cells containing a nucleus with two sets of chromosomes.
1) A good hypothesis for this researcher's investigation is ..
A) Do root tips treated with colchicines yield a nucleus with multiple sets of chromosomes?
B) Colchicines yields plants with mutant offspring
C) Colchicines destroys spindle fibers which results in cells with too many chromosomes
2) The experimental group was the group that the hypothesis is based on - TRUE OR FALSE
3) How many variables did the experimental group receive?
A) 1
B) 2
C) 3
D) 4
2 answers
Ummmm..... I think that the answer 2 #3 is A. Only plant B gets the chemicals so that iz the variable. Srry that i cant help wit anything else
The answer to 1 is A. It is more specific than B, and the experiment does not give any information about spindle fibers (C).
2) I'm not quite sure what is meant by "is based on." However, the experimental group's difference in changes from the control group will give evidence that either supports or contradicts the hypothesis.
3) There is one independent variable, but there are three extraneous variables that are controlled.
Here is some basic information on the experimental process that might help you in the future.
An independent variable is the potential stimulus or cause, usually directly manipulated by the experimenter, so it could also be called a manipulative variable.
A dependent variable is the response or measure of results.
Extraneous variables — other than the independent variable — potentially can affect the dependent variable, so they must be controlled. If possible, you try to keep them constant between the experimental and control group.
The experimental group receives the independent variable.
The control group is similar to experimental, except it does not receive the independent variable. Extraneous variables are balanced between experimental and control groups.
Types of experiments
1. Single blind gives the control group a placebo — a substance that is inert, it has no physical effect. Subjects don't know if they are in experimental or control group to reduce placebo effect, a change in behavior solely due to believing that you are getting the independent variable.
2. Double blind keeps both subjects and experimenter ignorant of group setup. Distribution of the independent variable and placebo is controlled by third party. This controls for experimenter bias and self-fulfilling prophecy. This means that experimenters with particular expectations are likely to consciously or unconsciously to bias the experiment and influence it to conform to their expectations.
As an example, suppose you want to find out if fluorides reduce dental cavities. You would find two groups, trying to control the extraneous variables. Extraneous variables are found by surveying previous research in the area. In this case, you would match the groups in terms of previous history of cavities, diet and dental hygiene habits including how and how often they brush their teeth.
The experimental group would get toothpaste with the independent variable, the fluoride, while the control group would not have the fluoride in their toothpaste. The toothpaste without the fluoride would be the placebo.
The dependent variable would be the number of cavities after participating in the experiment for a time. The dependent variable indicates the results, but it is not the results. At the end of the experiment, both groups could have no change in cavities or one of the groups could have a greater reduction in cavities. (Of course, if the fluoride increased cavities, you wouldn't want to use it.) All of these varied results would be indicated in terms of the dependent variable.
If only the subjects do not know who is getting the fluoride, it is a single blind experiment. If both the subjects and experimenter do not know, it is a double blind.
I hope this helps. Thanks for asking.
2) I'm not quite sure what is meant by "is based on." However, the experimental group's difference in changes from the control group will give evidence that either supports or contradicts the hypothesis.
3) There is one independent variable, but there are three extraneous variables that are controlled.
Here is some basic information on the experimental process that might help you in the future.
An independent variable is the potential stimulus or cause, usually directly manipulated by the experimenter, so it could also be called a manipulative variable.
A dependent variable is the response or measure of results.
Extraneous variables — other than the independent variable — potentially can affect the dependent variable, so they must be controlled. If possible, you try to keep them constant between the experimental and control group.
The experimental group receives the independent variable.
The control group is similar to experimental, except it does not receive the independent variable. Extraneous variables are balanced between experimental and control groups.
Types of experiments
1. Single blind gives the control group a placebo — a substance that is inert, it has no physical effect. Subjects don't know if they are in experimental or control group to reduce placebo effect, a change in behavior solely due to believing that you are getting the independent variable.
2. Double blind keeps both subjects and experimenter ignorant of group setup. Distribution of the independent variable and placebo is controlled by third party. This controls for experimenter bias and self-fulfilling prophecy. This means that experimenters with particular expectations are likely to consciously or unconsciously to bias the experiment and influence it to conform to their expectations.
As an example, suppose you want to find out if fluorides reduce dental cavities. You would find two groups, trying to control the extraneous variables. Extraneous variables are found by surveying previous research in the area. In this case, you would match the groups in terms of previous history of cavities, diet and dental hygiene habits including how and how often they brush their teeth.
The experimental group would get toothpaste with the independent variable, the fluoride, while the control group would not have the fluoride in their toothpaste. The toothpaste without the fluoride would be the placebo.
The dependent variable would be the number of cavities after participating in the experiment for a time. The dependent variable indicates the results, but it is not the results. At the end of the experiment, both groups could have no change in cavities or one of the groups could have a greater reduction in cavities. (Of course, if the fluoride increased cavities, you wouldn't want to use it.) All of these varied results would be indicated in terms of the dependent variable.
If only the subjects do not know who is getting the fluoride, it is a single blind experiment. If both the subjects and experimenter do not know, it is a double blind.
I hope this helps. Thanks for asking.
3 answers