Flatworms have no need for circulatory and respiratory systems because

The nucleaus of an atom is made up of particles that have a positive charge and (blank) that have no (blank).

What accounts for the variation Darwin observer among island species

A substance has a volume of 20 mL and a density of 2.5 g/mL. What is its mass? 0.125 g 8 g 22.5 g 50 g

Consider two populations of fish that live in separate ponds and differ in the frequency of alleles at a locus. after a flood, the two ponds become connected by a stream and some fish are able to move between the ponds.

In general, more complex animals are A) more likely to rely on chemical digestion than to rely on mechanical digestion. B) more likely to perform intracellular digestion than extracellular digestion.

How are unique daughter cells created in meiosis? A. Homologous pairing B. Crossing over C. Mutation during reduction Division D. Zygote fertilization

In any food web, which organism has the LEAST available energy? A) birds or omnivores B) plants or producers C) fungi or decomposers D) animals or carnivores

What organelle stores DNA in eurkaryotic cells?

What two genotypes would show as a dominant trait?

Lymphoma is a disease that prevents the lymph nodes from functioning properly. which would be a result someone having this disease a) they would be more likely to be harmed by common viruses b) they would be less likely to catch a cold or a flue c)