The objective of this work is the research on the acquisition of botanical content during biology lesson “Angiosperm” which is part of the regular curriculum of the second grade of grammar school. The study involved 170 students of second grade. Of the total number of pupils there were 64 male pupils and 106 female pupils. The classes were divided into two groups, experimental and control group. In each school, one class represented an experimental and other one control group. At the beginning of the lesson the initial test was given to the students, which was the same for both groups. The total solution of the initial test is 60.31%, and shows a better resolution of the test in the experimental group. After processing the teaching unit, the students solved the test for repetition. The total score of the repetition test is 56.43% and shows a better resolution of the test in the control group. The survey conducted revealed the dissatisfaction of students with the frequency and attendance of extra-curricular teaching in Biology. A total of 77.50% of surveyed students did not have one time attending extra-curricular classes during the year. Given the results of the tests, it is concluded that lecturing classes in Biology without the active participation of the students are taking place in the tested classes. From the whole research we can conclude that only by perseverance and constant work we can achieve the vision of a modern school in Croatia.