Select your answer:
Topics:
Blood & Blood Vessels The Nervous System Human Muscle Body System Interactions Musculoskeletal Anatomy: Knee Musculoskeletal/Endocrine Systems Healthy Foundations Mitosis for Mya Cell & Bond Regulation of Heart Rate Histology - Tissues Degeneration Pathology CNA Introduction CV System A&P & Pathology Immunology: T cell DevelopmentOther quiz:
Integumentary system › ViewThe waterproofing protein that fills the cells in the upper layers of the epidermis.
A. melatonin
B. keratin
C. melanin
D. actin
Vision › View
Detect blacks, whites, and grays, and are necessary for peripheral and twilight vision.
A. Rods
B. Cones
C. Light
D. Cells