Which of these statements is true? the gram-positive wall contains a thick peptidoglycan layer and is more complex than the gram-negative wall. the gram-negative wall contains a thick peptidoglycan layer and is more complex than the gram-positive wall. the gram-positive wall contains a thick peptidoglycan layer but is about as complex as the gram-negative wall. the gram-positive wall contains a thick peptidoglycan layer but is less complex than the gram-negative wall?