When an axon membrane reaches its threshold for an action potential, what type of ions enter from outside to inside?

Gina and Tina are identical twins who were separated at birth and grew up in different families. Which of the following aspects of their lives is more likely to be due to genetic similarities?

a. Both sing alto and are accomplished musicians. b. Both married men who were named Tim. c. Both drive red Mustang convertibles. d. Both use the same shampoo and toothpaste.

In the human growth sequence, a child who is between the ages of 15 to 18 months and two to two and half years old would be

a. in the pubescence period. b. in the senescence period. c. referred to as a neonate. d. referred to as a toddler.