Botanist ___________________________ Date ______________ Plant Kingdom 22-1 – PowerPoint Notes The Plant Kingdom Plants are classified as members of the kingdom ______________. Plants are eukaryotes that have cell walls containing _______________ and carry out photosynthesis using chlorophyll a and b. What Plants Need All plants have the same basic _______________: sunlight, a way to exchange gases with the surrounding air, water, and minerals. - Sunlight o Plants use the energy from sunlight to carry out _______________. o _______________ are typically broad and flat and are arranged on the stem so as to maximize light absorption. - Gas Exchange o Plants require _______________ to support cellular respiration, as well as carbon dioxide to carry out photosynthesis. o Plants must _______________ these gases with the atmosphere and the soil without losing excessive amounts of water through evaporation. - Water and Minerals o Land plants have evolved structures that limit _______________ loss and speed the uptake of water from the ground. o Minerals are nutrients in the soil that are needed for plant _______________. o Many plants have _______________ tissues that carry water and nutrients upward from the soil and distribute the products of photosynthesis throughout the plant body. Origins in the Water The _______________ of today’s land plants were water-dwelling organisms similar to today’s green algae. Although not as large and complex as many plants, green algae have cell walls and photosynthetic pigments that are identical to those of plants. Green algae also have _______________ cycles that are similar to plants. Studies of the _______________ of green algae suggest that they are so closely related to other plants that they should be considered part of the plant kingdom. The First Land Plants The greatest challenge that early land plants faced was obtaining _______________. They met this challenge by growing close to the ground in _______________ locations. Fossils suggest the first true plants were still dependent on _______________ to complete their life cycles. One of the earliest fossil vascular plants was Cooksonia, shown here. _______________ groups of plants evolved from the first land plants. One group developed into _______________. Another lineage gave rise to ferns, cone-bearing plants, and _______________ plants. An Overview of the Plant Kingdom Botanists divide the plant kingdom into _______________ major groups based on four important features: embryo formation, specialized water-conducting tissues, seeds, and flowers. The Plant Life Cycle The life cycle of land plants has two _______________ phases, a diploid (2N) phase and a haploid (N) phase. The shift between the _______________ phase and the _______________ phase is known as the alternation of generations, as shown in the figure. The multicellular diploid phase is known as the _______________, or spore-producing plant. The multicellular haploid phase is known as the _______________, or gamete-producing plant. A sporophyte produces haploid spores through _______________. These spores grow into multicellular structures called gametophytes. Each gametophyte produces _______________ cells called gametes—sperm and egg cells. During _______________, a sperm and egg fuse with each other, producing a diploid zygote that develops into a new sporophyte Trends in Plant Evolution An important trend in plant evolution is the _______________ in size of the gametophyte and the _______________ size of the sporophyte.