Among coelomates, which of these develops by spiral cleavage and the mouth forms before the anus

Protosomes

Explanation:

Protosome is a multicellular organism whose mouth grows before the anus from a primary embryonic opening which includesphyla mollusk, arthropod or annelid. Protosomes are developed by  spiral cleavage during embryo development.

Protosome animals have bilateral symmetry and three germ layers. Some of the examples of protostomes are snails and slugs (mollusk), earthworms (annelids), and spiders, lobsters, barnacles (arthropods).

Hence, the correct answer is Protosomes .

this is true, assuming that the allele is completely recessive and incomplete dominance is not a factor.

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.