(Q).
Q: The rate at which an unstable isotope decays is measured in a unit known as what?   Read this paragraph and choose the correct option from the provided answers:  The decay of an unstable isotope to a stable element occurs at a constant rate. This rate is different for each parent-daughter isotope pair. The decay rate is measured in a unit called the half-life. The half-life is the time it takes for half of a given amount of an isotope to decay. For example, the half-life of carbon-14 is 5,730 years. Imagine that you start out with 100 grams of carbon-14. In 5,730 years, half of it decays. This leaves 50 grams of carbon-14. Over the next 5,730 years, half of the remaining amount will decay. Now there are 25 grams of carbon-14. How many grams will there be in another 5,730 years? The figure below graphs the rate of decay of a substance ( Figure below ).   Choices:  - full-life  - staying-life  - half-time  - half-life   A:
(A).
half-life


(Q).
Q: What size of ring will a summer drought cause in a tree?   Read this paragraph and choose the correct option from the provided answers:  You can tell other things from tree rings too. In a good year a tree will produce a wide ring. A summer drought will produce a smaller ring. These variations will appear in all trees in a region. The same pattern can be found in all the trees in the area. This pattern helps scientist to identify a particular time period.   Choices:  - giant  - larger  - medium  - smaller   A:
(A).
smaller


(Q).
Q: The genetic code is universal, unambiguous, and what else?   Read this paragraph and choose the correct option from the provided answers:  6. The genetic code is universal, unambiguous, and redundant. Explain what this means and why it is important.   Choices:  - novel  - efficient  - functional  - redundant   A:
(A).

redundant