Predict the phenotype of a mouse ectoderm in an embryo harboring a mutation that alters bmp concentration.
-predict the phenotype of an organism exhibiting mutations in shh, bmp4/7, e-cad, n-cad
-compare the differences in cell behaviors and architecture between primary and secondary neurulation.

i think it's c

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.