AP BIOLOGY

Detailed explanation-1: -Life cycle. The life of a hornwort starts from a haploid spore. The spores can be yellow, brown or green. Yellow and brown spores have a thicker wall and contain oils that both protect against desiccation and function as a nutrient storage, allowing them to survive for years.

Detailed explanation-2: -that grows out from a bulbous foot embedded in the thallus is entirely spore capsule. To see the foot you need to dissect the hornwort. The immature sporophyte is green and so, like the immature moss sporophyte, photosynthesizes.

Detailed explanation-3: -Hornworts produce green spikes (horns) that mature and slowly split lengthwise from the tip down, making and releasing their spores slowly.

Detailed explanation-4: -Hornworts reproduce sexually by means of waterborne sperm, which travel from the male sex organ (antheridium) to the female sex organ (archegonium). A fertilized egg in a female sex organ develops into an elongate sporangium, which splits lengthwise as it grows, releasing the spores that have developed within it.