The following statements pertain to the development of the theory of the structure of dna. match the statement with the appropriate step (observation, hypothesis, experiment designed to test hypothesis) in the scientific method. a. two strands of dna wind around one another in a helical structure. b. in a sample of dna, there are equal amounts of the bases a and t and equal amounts of the bases c and g. c. direct x-rays at a sample of crystallized dna and interpret the diffraction pattern for structural information.

The correct answer will be-

1. Observation-option B.

2. Hypothesis-option A.

3. Experiments- option C.

Explanation:

A scientific method involves various steps to explain a natural phenomenon of nature. It begins with making an observation which leads to asking the scientific question. The researcher does background research and proposes a hypothesis which could be tested through experiments. The experiments could prove or disprove the hypothesis based on the results.

In the given question the observation made is an equal amount of A and T and G and C are observed. It leads to a hypothesis which shows that this could have happened due to the winding of two strands of DNA and the experiments was performed through X-ray diffraction pattern.

Thus, the selected options are the correct answer.

interphase

the period of cell growth when the cell synthesizes new molecules and organelles. the cell is not dividing and it constitutes the majority of the time spent in the cell cycle

prophase

changes occur in the nucleus and cytoplasm. the chromatin condenses to form structures (sister chromatids) visible with a light microscope and the mitotic spindle begins to form, but the nucleus is still in tact

prometaphase

the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the sister chromatids

metaphase

all the cell's duplicated chromosomes are lined up at an imaginary plane equidistant between the poles of the mitotic spindle

anaphase

begins when sister chromatids separate from each other and ending when a complete set of daughter chromosomes arrives at each of the two poles of the cell

telophase

the daughter nuclei form at the two poles of a cell

cytokinesis

the division of a cytoplasm to form two separate daughter cells. usually occurs during telophase during mitosis. this and mitosis make up to mitotic (m) phase of the cell cycle