4. Compare and contrast a mechanical wave and an elec-
tromagnetic wave.
How are they similar and different

difference:

1. The generation mechanism is different, the mechanical wave is generated by mechanical vibration; the electromagnetic wave generation mechanism is also different, there is the periodic movement of electrons (radio waves); the outer electrons with atoms are generated after being excited (infrared, visible, ultraviolet) The inner electrons with atoms are generated after excitation (roentgen rays); the nuclei with atoms are generated after excitation (gamma rays).

2. The propagation mechanism is different: the mechanical interaction between the particles and the alternating induction of the electromagnetic field.

3. Mechanical waves have both transverse waves and longitudinal waves; electromagnetic waves are material waves and belong to transverse waves.

4. The influence of the medium on the propagation speed is different

Explanation:

https://qiaodahai.com/similarities-and-differences-between-mechanical-waves-and-electromagnetic-waves.html

p

explanation:

the answer is d.) homologous; have mammary glands