Why might the scientists have chosen changes in CO2 as an indicator of photosynthesis rather than
changes in the quantity of energy rich compounds
such as ATP and NADPH within the leaves?

Because it is easier to measure

Explanation:

Measuring the production of ATP or NADPH is challenging and requires some advanced methods in a a research laboratory.

However, the production of a gas is much easier to measure, and can be done in school laboratories. For example, by observing the production of bubbles or using a gas cylinder can tell how much CO2 is being produced.

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.

spiders belong to a group of arachnids.

arachnids have the following traits :

they have two body parts.

they have eight legs unlike insects which have 6 legs.

they have no wings.

these traits distinguish them from insects.

the information that antonio is doubting us the statement that spiders differences are as a result of being first to evolve.

this is because the evolution of one species is independent of the other species.