What was anton van leeuwenhoek's contribution in the development of cell theory? a. he built the first compound microscope. b. he was the first to observe live cells in a sample of pond water. c. he concluded that cells exist in liquids. d. he stated that all living things are made of cells. a. he built the first compound microscope. b. he was the first to observe live cells in a sample of pond water. c. he concluded that cells exist in liquids. d. he stated that all living things are made of cells.

Apopulation of black bears depends on salmon from a stream for food. if a drought causes the stream to run dry one year, how will this likely impact the black bear population?

Milk production during breastfeeding is increased by the suckling of a newborn from his mother's nipple. this type of feedback mechanism best describes a positive or negative

Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. an incomplete dominance cross is performed between a bird that is homozygous for red feathers and a bird that is homozygous for blue feathers. purple offspring result. then, two of the purple offspring are crossed. according to the punnett square for this cross, how many of the offspring from the second cross will have a feather color that results from incomplete dominance? 1 in 4 2 in 4 3 in 4 4 in 4