Insulin is produced by the beta cells of the pancreas. Glucagon is produced by the alpha cells of the pancreas. Insulin causes target cells to take up glucose from the blood. Glucagon causes liver cells to break down glycogen into glucose, and to release glucose into the blood. The corpus luteum secretes estrogen and progesterone.
Fish normally exchange the following chemical compounds with the environment through their gills.
Chrysanthemums are 'short day' plants whose critical day length for flowering is 14 hours. Circle the correct answers. For each pair of statements below, mark the one statement that is true of a gametophyte . Tissue cells are haploid. Tissue cells are diploid.