SI Leader Justin Remmell Course Biology 242 01 Instructor Dr Hoffmann Spring 14 Chapter 30 Plant Diversity II and the Evolution of Seed Plants 1 A consists of an embryo and its food supply surrounded by a protective coat 2 Characteristics all common to seed plants 3 While the gametophytes of seedless vascular plants are to the naked eye the gametophytes of seed plants are mostly 4 Seed plants are unique in retaining the and within the sporophyte 5 Ovule development in gymnosperms A megasporangium containing 1 megasporocyte undergoes to form 4 n cells There is one two three four functional megaspore o The functional megaspore goes through divisions to produce a multicellular female n containing several each with one egg A layer of sporophyte tissue envelops and protects the megasporangium The whole structure megasporangium megaspore and their integument s is called an Inside each ovule a female develops from a megaspore and produces one or more 6 Pollen development in Gymnosperms enclosed within the pollen wall A microspore develops into a that consists of a male gametophyte The tough pollen wall consisting of protects a pollen grain as it is transported from the parent plant by the wind The transfer of pollen to the part of a seed plant that contains the ovules is called A microsporangium containing the microsporocytes undergoes to produce 4 microspores Each of these divides to get 4 celled pollen grains 7 initiates the transformation of the ovule into a consisting of An 2n Female gametophyte tissue n Derived from integument 8 Gymnosperms are plants that have seeds that are not enclosed in ovaries Their seeds are exposed on modified leaves that usually form cones 9 Gymnosperms have a conspicuous 10 Cone bearing gymnosperms are called which include spruce pine fir and redwood 11 The life cycle of a pine In most conifer species each tree has both and cones occurs when a pollen grain reaches the ovule The pollen grain then forming a pollen tube that slowly digests its way through the 2n occurs when the sperm and nuclei unite This usually occurs more than a year after pollination 12 The reproductive adaptations of angiosperms include and 13 Only one angiosperm phylum Phylum 14 The is an angiosperm structure specialized for sexual reproduction 15 Flower organs are at the flower base enclose and protect the flower are brightly colored modified leaves Aid in attracting pollinators are male reproductive organs consisting of the filament and the anther where the pollen is produced are composed of one or more carpels the stigma received pollen style leads to the ovary and the ovary contains one or more ovules 16 A typically consists of a mature ovary although it can include other flower parts They protect seeds and aid in their dispersal 17 Pollen development On each anther the 2n divide by meiosis to produce 4 n The microspores divide by to form a 2 celled pollen grain containing a n and generative cell o The generative cell divides forming two sperm o The tube cell produces the pollen tube 18 Ovule development in ovary carpel The ovule contains an and The megasporocyte undergoes meiosis to produce haploid cells 3 of 2n which are The functional megaspore n undergoes mitotic divisions from which the female 8 celled embryo sac arises The embryo sac contains antipodal cells polar nuclei in central cells synergid cells and egg cell 19 In angiosperms is the transfer of pollen from an anther of a flower one plant to the stigma of a flower on another plant the plants are the same species 20 Angiosperms undergo in which one fertilization event produces a zygote and the other produces a triploid cell This triple cell is the tissue rich in starch and other food reserves that nourish the developing embryo