Which of the following bacteria lack a cell wall and are therefore resistant to penicillin? a. cyanobacteria b. mycoplasmas c. bdellovibrios d. spirochetes the protein from which hook and filaments of flagella are composed of, is a. keratin b. flagellin c. gelatin d. casein a cluster of polar flagella is called a. lophotrichous b. amphitrichous c. monotrichous d. petritrichous the cooci which mostly occur in single or pairs are a. streptococci b. diplococci c. tetracocci d. none of these flagella move the cell by a. many flagella beating in a synchronous, whip-like motion b. an individual flagellum beating in a whip-like motion c. spinning like a propeller d. attaching to nearby particles and contracting