Deformity development poem

(1) All living things can respond to external stimuli, such as paramecium stress, human conditioned reflex, bird migration, phototropism of plants, hydrotropism and geotropism of plant roots, wilting of plants at noon in hot summer, response of mimosa to external stimuli, etc. So frogs stop chirping when someone approaches, which shows that creatures can respond to external stimuli.

(2) "Frogs croak for courtship" is a trait passed down from generation to generation by frogs, which reflects that organisms have genetic characteristics.

(3) The eggs produced by frog courtship develop into frogs through tadpoles and young frogs. There are great differences between frog larvae and adults in system structure and living habits. Frog larvae live in water, and adults can live in water or wetlands through gill breathing, and it is abnormal development through lung breathing.

(4) Frog larvae live in water and breathe through gills, while adults can live in water and wetlands. Breathing through lungs shows that the changes of their respiratory organs are from gills to lungs.

So the answer is (1) reaction.

(2) heredity

(3) Abnormal development

(4) gill to lung