Phase 3: Sequencing the Questions
According to the Logic of Student
Learning is a process of developing an understanding, and the role of
teaching is to promote this process. Therefore, the instructional process should follow the logic of student cognitive development. The
order of questions in Table 2 corresponds with that of the concepts
in Table 1, which conforms to the logic of knowledge on the subject
being taught. However, this logic is rarely aligned with the logic of
student cognitive development (National Research Council, 2000).
It is necessary for teachers to reorder the questions in Table 2 according to the logic of student cognitive development. Answers to some
questions may provide the fundamental knowledge for answering
other questions. The questions in Table 2 are thus reordered in Table 3.
Phase 4: Selecting Resources &
Designing Tasks to Create Learning
Coupling knowledge with practice provides the learning context,
What Are Homologous Chromosomes?
whereas knowledge presented alone is memorization (National
Research Council, 2013). Directly answering the questions in Table 3
is just a process of recalling content knowledge, which contributes
little to the construction of an understanding of concepts. To help
students experience a process of evidence-based learning and
develop an understanding of concepts through their own thinking,
teachers should carefully consider the problem of creating learning
situations. Two major elements constitute learning situations.
One is resources, which can provide students with direct or indi-
rect evidence with which to answer questions, such as data, charts,
experiments, history of science, and science-related issues. The
other is tasks, which refers to the manner in which students obtain
evidence, such as by analysis, observation, investigation, argumen-
tation, and reasoning. The learning situations designed for each
question in Table 3 are described below.
• Expectations. Students will explain that chromosomes occur in
pairs in the body cells of animals and most plants; in each pair,
one chromosome came from the male parent, and the other came
from the female parent; this pair of chromosomes is referred to as
• Resources. Display of human karyotypes (Figure 1).
• Tasks. The task is to examine Figure 1. This demonstrates that in
human body cells, chromosomes occur in pairs called homologous
chromosomes. A pair of homologous chromosomes consists of one
maternal and one paternal chromosome. Each pair of homologous
chromosomes carries genes for the same traits.
What Is Haploid?
• Expectations. Students will explain that a cell with two of each kind
of chromosome is called a diploid cell, and a cell containing one of
each kind of chromosome is called a haploid cell.
• Resources. The resource provided is a display of human karyotypes (Figure 1).
Table 2. Initial questions that correspond with concepts in Table 1.
Concept Codea Initial Question(s)
HS-M 1 What is meiosis?
HS-M 1.1 How is the chromosome number in the daughter cells reduced by half?
HS-M 1.2 What happens in Meiosis I? What are homologous chromosomes?
HS-M 1.3 What happens in Meiosis II?
HS-M 2 Why is meiosis necessary for organisms? What is haploid?
Table 3. Logical sequence of questions in Table 2 according to student cognitive development.
aHS = high school; M = meiosis.
Logical Sequence Concept Codea Initial Questions
1 HS-M 1.2 What are homologous chromosomes?
2 HS-M 2 What is haploid?
3 HS-M 2 Why is meiosis necessary for organisms?
4 HS-M 1.1 How is the chromosome number in the daughter cells
reduced by half?
5 HS-M 1.2 What happens in Meiosis I?
6 HS-M 1.3 What happens in Meiosis II?
7 HS-M 1 What is meiosis?
aHS = high school; M = meiosis.