Lancelets is the group of chordates that has a notochord and includes separate males and females.
Lancelet exhibits the four basic characteristics of phylum Chordata. It has a dorsal nerve, a notochord, a post annul tail, and pharyngiall gill slit.
Jawless fish, cartilaginous fish, and bony fish have notochord when they were still young but it was replaced by a vertebral column as they mature.
<span>Lancelets are included in the subphylum cephalochordata. Cephalochordates are gonochoristics. It means that the sexes are separate. Both sperm and eggs cells are released in the water where fertilization occurs.</span>
"Answer DThe outermost layer of old epidermal cells are sloughed off and replaced every 15 to 30 days. The sebaceous glands secrete sebum which maintains the skin pH between 3 and 5. Bacteria which metabolize sebum live as opportunistic pathogens on the skin and cause skin infections."
for instance in humans, the somatic cells include 46 chromosomes which is the diploid wide variety (2n) and each sperm and egg has 23 chromosomes wherein one of them is the sex chromosome.
