On a timer!
a geologist finds a metamorphic rock and notices that it has grains that formed in parallel layers. the geologist pries at the rock, and it splits apart along the bands formed by the layers.

which type of rock did the geologist most likely find?

gneiss
limestone
marble
sandstone

Option A, gneiss

Explanation:

Metamorphic rocks are classified based on their grain arrangement in to  foliated rocks and non- foliated rocks. These foliated rocks are the ones in which the grains are arranged in parallel layers bands which allows them to   split apart along these band. Some common examples of foliated metamorphic rocks are slate, schist, and gneiss

Thus , option A gneiss is the correct answer.

layer 3 is younger than layer 6.

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.