Name the structures marked R and S on Fig. 7.1.
State three visible features on Fig. 7.1 that show the chromosomes are a homologous pair.
Fig. 7.2 shows the same two chromosomes a little later in that same stage of meiosis. Crossing over is starting at point T. Fig. 7.3 gives an outline of those same two chromosomes after crossing over has taken place. Complete Fig. 7.3 by filling in the allele letters along both chromosomes. Be careful to show clearly the difference between letters for dominant alleles and letters for recessive alleles.
State the stage in meiosis during which crossing over occurs.
Complete Fig. 7.3 by adding the allele letters along both chromosomes. Be careful to show clearly the distinction between letters that stand for dominant alleles and letters that stand for recessive alleles.
Crossing over causes genetic variation. Explain how random assortment of homologous chromosomes also causes genetic variation.