Myofibrils within cardiac muscle cells are aligned in sarcomeres. a. true b. false

Question 17 (1 point) where does penicillin come from? a. it is a chemical that man invented b. it is a fungus c. it is a toxin made by other bacteria d. it was discovered in archaebacteria

Which of the following structures is a double layer of phospholipids with proteins? a: cytoplasm b: cell membrane c: ribosome d: cell wall

Which sex chromosome contains more genes? a. x b. y c. r