Question

chapter 1: scientific inquiry and biology

1. a researcher conducts an experiment on corn seedlings and uses the results to make predictions and conclusions about all plants. explain the researchers error in using the results in this way.
2. why is it important for a scientist to include all the steps that he or she used to conduct an experiment when writing the research report for other scientists to read?

part c—reading comprehension
base your answers to questions 34 to 36 on the information below and on your knowledge of biology.
the main purpose of science is to look at events, occurrences, and patterns in nature and develop explanations for them. these explanations can always be changed as new observations are made and new evidence is found. a possible explanation of a natural event or pattern is called a hypothesis. charles darwin, in his own words, showed why he was a true scientist.
from my early youth i have had the strongest desire to understand or explain whatever i observed - that is, to group all facts under some general laws. i have steadily endeavoured to keep my mind free so as to give up any hypothesis, however much beloved (and i cannot resist forming one on every subject), as soon as facts are shown to be opposed to it. i follow a golden rule that when ever a published fact, a new observation or thought came across me which was opposed to my general results, to make a memorandum of it without fail and at once: during some part of the day i write my journal, and take much pains in describing carefully and vividly all that i have seen; and this was good practice. and this habit of mind was continued during the five years of the voyage. i feel sure that it was this training which has enabled me to do whatever i have done in science.
on the voyage of the beagle, darwin saw seeds that had washed ashore on a small island near australia. he wondered whether seeds could travel long - distances in the ocean and still be able to grow. back in england, he enthusiastically filled his home with bottles of seawater. darwin soaked many different kinds of seeds in the salty water, for short and long periods of time. he used a variety of crop seeds - such as cabbage seeds, lettuce seeds and celery seeds - 23 kinds in all. he then tried to grow them in soil. darwins experiments showed exactly what the scientific method is. state the problem, collect information, form a hypothesis, perform an experiment, record observations and data, draw a conclusion, and share your results.

1. when does a scientist find it necessary to change a hypothesis?
2. why did charles darwin keep a journal?
3. describe how darwin followed each of the steps of the scientific method in his experiment with seeds and salt water.

Explanation:

1. A scientist finds it necessary to change a hypothesis when new observations or evidence are made that oppose the existing hypothesis. As stated in the text, explanations in science can change as new observations are made and new evidence is found.
2. Charles Darwin kept a journal to make a memorandum of new observations or thoughts that came across him, and to describe carefully and vividly all that he had seen. This was good practice and the habit of mind continued during his voyage and scientific work.

36.

• Problem: Whether seeds could travel long - distances in the ocean and still be able to grow.
• Collect information: He saw seeds that had washed ashore on a small island near Australia.
• Form a hypothesis: Not explicitly stated in the text but implied as the idea that seeds can survive ocean travel and grow.
• Perform an experiment: He soaked many different kinds of crop seeds in salty water for short and long periods of time and then tried to grow them in soil.
• Record observations and data: He recorded the results of which seeds grew and which did not.
• Draw a conclusion: His experiments showed something about the ability of seeds to survive salt - water exposure and grow, though the exact conclusion isn't fully stated in the provided text.
• Share results: The text doesn't mention this step in relation to Darwin's seed experiment specifically, but in general, scientists share results.

Answer:

1. A scientist changes a hypothesis when new observations or evidence oppose it.
2. Darwin kept a journal to record new observations and thoughts and to describe what he saw.
3. Problem: Whether seeds can travel in the ocean and grow. Information: Saw seeds on an island. Hypothesis: Implied that seeds can survive and grow. Experiment: Soaked seeds in salt - water and tried to grow them. Observations: Recorded which seeds grew. Conclusion: Results about seed survival and growth. Share results: Not mentioned for this experiment specifically.