Which of the following best describes the term parasitism?

one species uses another species as a food source, typically killing it.
one species uses another species as food or shelter causing harm.
one species takes food or resources away from another species.
one species can photosynthesize or otherwise create its own food.

(select all the correct choose each statement that is scientific. - the opinions of randomly selected participants in a survey prove the idea that global temperatures are not increasing on earth. - the universe's average temperature and rate of expansion support the idea that it began as one super-dense and hot mass 13.8 billion years ago. - ocean tides are caused by the uneven gravitational pulls of the moon and sun on different parts of earth. - human life is more valuable than other forms of life on earth because humans are more intelligent than other organisms.

Which best describes a gene? a. a sister chromatid b. a chromosome c. a tetrad d. a piece of a chromosome

What does the number 18.9984 represent in the image?