The echinoderm that differs from all others in that it lacks an endoskeleton, and only retains small bony pieces in its skin is the

(A) sand dollar

(B) sea lily

(C) brittle star

(D) sea cucumber

In pea plants, yellow seed color (y) is dominant and green seed color (y) is recessive. based on the punnett squares, what are the chances that the offspring in the second generation will have green seeds?

Which of these is true of the cytoplasm of an unfertilized egg? a. it is an unevenly distributed mixture of mrna, proteins, organelles, and other substances. b. it does not contain substances that are important in directing development. c. these substances are supplied by the sperm. d. it does not contain substances that are important in directing development. e. development is directed solely by the surrounding cells. f. it is a homogeneous mixture of mrna, proteins, organelles, and other substances. g. it does not contain substances that are important in directing development. h. these substances are produced by the dna of the fertilized zygote.

Why is there more biomass at the producer level that at the consumer levels ? how does this relate to the 10% rule ?