4. Which system helps keep you healthy by carrying white blood cells throughout the body which trigger immune responses when needed?
O A. Digestive system
B. Endocrine system
C. Respiratory system
D. Lymphatic system
5. True or False: The excretory system is responsible for inhaling and exhaling,

Use the drop down menus to match each example to the fossil topic discussed then to show how the fossil record gives evidence of evolution

Ascientist separates a population of mice into two groups. what would most likely increase the rate of speciation in this population. a. teach the two groups different tricks b. allow the two groups to breed with each other c. put the two groups in different environment d. have the two groups live in identical ecosystems

What causes darkening of the skin as melanin production increases