Suppose that a carrier of familial down syndrome mated with a person with a normal karyotype. which gamete from the carrier parent could fuse with a gamete from the normal parent to produce a trisomy-21 zygote?

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]

1. is geographic distribution

2 is increasing complexity

3 is transitional forms