How do I remember what adaptations plants and animals have in dry conditions? How would I answer this in a question?

A main concern for both plants and animals is to hold onto as much water as possible and prevent evaporation wherever possible, which you should keep in mind when trying to recall what kinds of features they will have. Let's look at plants and animals separately (I have just provided a few examples of adaptations for both, but you should be able to find further examples in revision books).

For plants, a main adaptation feature is having a small surface area to reduce water loss to evaporation. The presence of spikes instead of leaves, and having fewer stomata also helps with this. They also tend to have roots which are long and cover a larger area to increase their chance of absorbing water. Finally, large and fleshy stems will help to store any water they absorb.

For animals, a smaller surface area also helps to reduce water being lost through radiation and evaporation. Some animals may have fat stores (such as a hump) where fat can be converted to water through respiration. But it's not just about conserving water. To keep cool, animals may have a reduced amount of body fat to reduce heat insulation, or be nocturnal (active at night) to avoid the heat in the day.

To do well in this question you will need to give examples for both plants AND animals. You also need to talk briefly about why at least one of the adaptation features will help the plant/animal survive in a dry environment (e.g. a desert). For example, rather than just saying "many plants have long and widespread roots", you could say "many plants have long and widespread roots to allow the absorption of more water".