Chelsea is researching an organism. Her organism has jointed limbs and an exoskeleton. It also obtains air through air tubes. Chelsea’s organism is classified as a/an
A. amphibian
B. echinoderm
C. mollusk
D. arthropod

Where is having brightly colored feathers that attract mates most clearly an adaptation for a bird? a. a forest with dense vegetation b. a sandy beach beside an ocean c. a snowy tundra with little vegetation d. a swamp with many hawks that eat birds

Which if the following best describes why invertebrates isn’t considered a scientifically valid word when classifying animals

I've created a synthetic cellular membrane that is made up of phospholipids, but contains no proteins. which of the types of movements across a membrane would not function with my synthetic membrane?