Question

Question 4 1 pts Compare and contrast the fertilization processes of gymnosperms and angiosperms. Be sure your answer includes structures and/or events that are unique to each of these two groups of seed plants. HTML Editora BIVA-A I E x x - DC V V T 114 12pt . Paragraph O words

Answer 1

Answer

Gymnosperms are a group of seed producing plants that includes conifers, cycads, Ginko and gnetophytes. Angiosperms are also called flowering plants, here flowers are the reproductive organ and they may be both unisexual and bisexual They have seeds that are. enclosed within an ovary (usually a fruit), After fertilization, the ovules develop into seeds inside the fruit. While Gymnosperms have no flowers or fruits, and have enclosed or "naked" seeds on the surface of scales or leaves. In Gymnosperm the reproductive structure are cones which are unisexual. Gymnosperm seeds are often configured as cones. The ovules are exposed,ie., they are not located in ovary. After fertilization ,the ovules develop into naked seeds.

In Angiosperms pollination is defined as the placement or transfer of pollen from the anther to the stigma of the same or a differnt flower. In gymnosperms , fertilization is simple. Pollination involves pollen transfer from the male cone to the female cone .Upon transfer, the pollen germinates to form the pollen tube and the sperm that fertilize the egg.

Angiosperms,or flowering plants, undergo a unique process called Double fertilization. After pollination brings a pollen grain to a flower's female reproductive structure (carpel) , a pollen tube releases two sperm cells.One of these sperm cells unites with an egg to produce a diploid zygote. In order for fertilization to occur in most flowering plants, insects or other animals must transport the pollen to the pistill. when a pollen grain comes into contact with the stigma, or top of the pisitil, it sems a pollen tube down into the ovary at the pistil's base. The microspores are produced in anther while the megaspores are produced in ovules in the ovary in flowers.

In Gymnosperms , the female gametophyte contains several archegonia, where the egg cells originate and develop . Fertilization occurs when pollen grains (male gametophytes) are carried by the wind to the open end of an ovule, which contains the eggs, or female gametophyte. The endo sperm is haploid. Unlike angiosperms, ovaries are absent in Gymosperms, double fertilization does not takes place, male and female gametophytes are present on cones rather than flower, and wind ( not animals) drives pollination.