Which of the following is a characteristic of all living things? A. obtain energy from an outside food source 3. maintain homeostasis C. sexual reproduction D. multicellular Single-celled organisms, such as paramecia, are able to sense a food source and move toward it. Which key characteristic of all living organisms does this example illustrate? A. regulation and homeostasis B. sensitivity and responsiveness to the external environment C. adaptation to environment D. ability to grow and reproduce Viruses contain genetic material, and they can evolve over time and adapt to their environment. However, they also must use the machinery of the host cells they invade to reproduce and do not carry out any metabolic processes on their own. Based on this description, should viruses be classified as "living? A. Yes. Viruses contain genetic material, just like other living things. B. Yes. Viruses have the ability to adapt and change. C. Yes. Reproduction is one of the characteristics of living organisms. D. No. Viruses cannot reproduce or conduct metabolic functions on their own. Scientific study always begins with: A. hypotheses. B. data. C. observations. D. experiments. The proposed explanation for a phenomenon is best described as A. an experiment. B. an observation. C. a testable prediction. D. a hypothesis. If your hypothesis is, "Echinacea reduces the duration and severity of the symptoms of the common cold," what is your null hypothesis ? A. Echinacea increases the duration and severity of the symptoms of the common cold. B. Echinacea reduces the duration and severity of the symptoms of the flu. C. Vitamin C reduces the duration and severity of the symptoms of the common cold. D. Echinacea has no effect on the duration and severity of the symptoms of the common cold.

Ans 1. Which of the following is a characteristics of all living things

The answer is B. maintain homeostasis.

Ans 2. The key character illustrated by the organism is B. sensitivity and responsiveness to the external environment

Ans 3. The answer is C. Yes. Reproduction is one of the characteristics of living organisms.

Ans 4. A scientific study always begins with observation of previous data.

So, the answer is C. observations

Ans 5. The proposed explanation for a phenomenon is called hypothesis

So, the answer is D. a hypothesis.

Ans 6. The null hypothesis will be as follows:

So, the answer is D. Echinacea has no effect on the duration and severity of the symptoms of the common cold.

For a proper explanation of each question, I have numbered the questions from top to bottom serially for your convenience.

Ans 1. All living organisms required energy but not all obtain from external sources as is the case with phototropic organisms who can prepare their food hence option A is wrong.

All living organisms maintain homeostatic because cells require ideal conditions such as appropriate temperatures, pH, and the correct concentration of a range of chemicals to work properly. Nevertheless, these circumstances will change from time to time. Despite environmental changes through homeostasis (literally, "stable status") - an organism's ability to maintain constant internal conditions, organisms can maintain internal conditions in a limited scope almost continuously. For instance, through a process called thermal regulation, an organism may regulate body temperature.

But all living organisms do not reproduce sexually as lower organisms reproduce asexually. Not all living organisms are multicellular because there are many lower unicellular organisms.

Ans 2. The movement of paramecium towards food source is the response of paramecium to an external stimulus that is food which it requires for growth and development. This phenomenon is common to all unicellular organisms and they respond to many such stimuli like light, chemical, etc.

Ans 3. Viruses are considered as the connective link between living and dead because they act as a particle of protein with a genetic material outside the host cell but stars to behave like a living organism as soon as they enter the host cell and start reproducing as a living organism which proves they are living else they would have been considered as dead organism. That is why they are called a connective link between living and dead. So they are living as Reproduction is one of the characteristics of living organisms.

Ans 4. There are fundamental methods that are common to all sciences to gain knowledge. The scientific analysis which is conducted by the scientific method is at the heart of the science. Scientific research is a program to ask questions and to check responses. Typically, a scientific study starts with observations. You always make observations. This often leads to questions that lead to the formation of a hypothesis.

Ans 5. A proposed explanation for a phenomenon is a hypothesis. The scientific method allows one to test a theory to be a valid hypothesis. Scientists are generally based on past findings, which can not be explained satisfactorily by current scientific theories. Although the term hypothesis and theory are often synchronously used, a scientific hypothesis is not the same as a theory of science. One working hypothesis is a theory suggested provisionally for further study, beginning with well-trained speculation or thought.

Ans 6. A null hypothesis is a hypothesis which states that between the two variables in the hypothesis there is no statistical significance. The researchers are seeking to challenge this theory. The null hypothesis is challenged and usually wishes to disprove this to demonstrate that the two variables in the hypothesis are statistically significant.