TABLE 3.
Interviews from biology students and experts reveal differences between how students and biology experts approach meiosis-related topics
| Questions posed | Typical student ideas | DNA (C/M/I)a | Typical expert ideas | DNA (C/M/I)a |
|---|---|---|---|---|
| What does ploidy mean? | Ploidy is determined by the structure of chromosomes; replicated, two-DNA chromosomes are considered diploid and unreplicated, one-DNA chromosomes, are considered haploid. | C | A diploid cell has two of each “type” of chromosome, one maternal and one paternal. | C |
| Ploidy is defined by the number of unique sets of information in a cell. | I | |||
| What are homologous chromosomes? | Homologous chromosomes have the same size and shape. | C | Homologous chromosomes are nearly identical at the sequence level. Alleles of the same gene may only differ by a single base. | M |
| Homologous chromosomes share the same genetic information (same genes or alleles). | I | Homologous chromosomes contain the same genes in the same order but often contain different alleles. | I | |
| What determines homologous pairing? | Little knowledge about how or why homologous chromosomes pair is evident. | — | Homology at the DNA sequence level allows chromosomes to interact. | M |
| Homologous pairing is essential for proper segregation. | I | |||
| What is crossing over? | Crossing over involves segments or chunks of sister chromatids exchanging places. | C | Crossing over occurs when complementary sequences interact and form a physical connection between chromosomes. | M |
| It is important for creating “genetic diversity” so “evolution can happen.” | I | It is a way for homologous chromosomes to swap information—create new combinations of alleles—so every gamete is genetically different. | I |
a
The corner of the DNA triangle referenced in the answer: C, chromosomal; M, molecular; I, informational.