Plant Adaptations Bio.2.1.2 Analyze the survival and reproductive success of organisms in terms of behavioral, structural, and reproductive adaptations.

Plants Plants are divided into four groups: Nonvascular – mosses They can’t transport water upwards Always found in wet areas like along river banks sperm swim to the eggs Vascular and seedless – ferns they can only reproduce when there is enough moisture

Plants Plants are divided into four groups: Gymnosperms – pine trees sperm (pollen) gets to the egg using the wind Sperm and eggs are on cones Angiosperms – flowering plants Sperm (pollen) gets to the egg using pollinators, wind, or water Flowers become fruit after fertilization Fruit protects the seeds

Plant Structural Adaptations Three adaptations have allowed plants to be successful on land: a waxy cuticle to prevent water loss haploid spores and diploid seeds to protect reproductive cells special vascular tissues called xylem and phloem for absorbing and transporting materials within the plant.

Plant Structural Adaptations Early land plants lacked leaves and roots and consisted of only stems. Leaves evolved from branches of stems, and flowers are considered to be highly specialized branches and the parts of a flower to be specialized leaves.

Plant Structural Adaptations Leaves are the primary site of photosynthesis in most plants. In most leaves the epidermis is a single layer of cells coated with cuticle, to protect from water loss. Also in the epidermis is the stomata, for gas exchange, and epidermal hairs.

Plant Structural Adaptations The vascular tissue system of leaves consists of vascular bundles called veins, which are made of xylem and phloem. Veins are continuous with the vascular tissue of the stem and the roots.

Plant Structural Adaptations A major limitation to plant photosynthesis is insufficient water due to transpiration, loss of water through the stomata. Transpiration may benefit the plant by cooling it and by speeding the transport of mineral nutrients from the roots. Plants must balance their need to open their stomata to receive carbon dioxide and release oxygen with their need to close their stomata to prevent water loss through transpiration.

Plant Reproductive Adaptations All plants have a life cycle known as alternation of generations. In alternation of generations, a haploid gametophyte produces gametes. Gametes unite and give rise to a diploid sporophyte. Through meiosis, the sporophyte produces haploid spores, which develop into gametophytes.

Plant Reproductive Adaptations Mosses and ferns can do asexual or sexual reproduction. When you see a clump of moss or a bunch of fern you are probably seeing clones. As long as the environmental conditions are favorable asexual reproduction takes less time and resources.

Plant Reproductive Adaptations Gymnosperms will produce two types of spores (gametophytes)— male microspores, which becomes pollen, and female megaspores, which become eggs. Pollen allows sexual reproduction in seed plants to take place independent of seasonal rains or other periods of moisture. Pine trees release a lot of pollen.

Plant Reproductive Adaptations Gymnosperm sexual reproduction can take more than two years. During the first summer, a mature pine tree produces separate female and male cones. Pollen lands on the female cone and makes a pollen tube to reach the egg. The following spring, the seed is released by the female cone.

Plant Reproductive Adaptations Flowering plants are called angiosperms. The male reproductive structures are stamens, each of which consists of an anther and a filament. .

Plant Reproductive Adaptations Female reproductive structures are called carpels, which make up the pistil. The base of a pistil contains the ovary, which will produce eggs. The style arises from the ovary and tip of the style is called the stigma.

Plant Reproductive Adaptations Pollen grains, the male gametophytes, form within the anthers of the stamens. Pollination occurs when pollen grains are transferred from an anther to a stigma. Angiosperms can undergo self-pollination or cross- pollination. Bright petals and distinctive odors attract animals and pollen sticks to their bodies. As they go to other flowers, the animals deposit some of the pollen on other flowers. https://www.youtube.com/watch?v=-h8I3cqpgnA

Plant Reproductive Adaptations After the egg is fertilized the ovary turns in a fruit. Fruits protect seeds, aid in their dispersal, and often delay their sprouting.

Plant Reproductive Adaptations Although its embryo is alive, a seed will not germinate, or sprout, until it is exposed to certain environmental conditions. Many seeds will not germinate even when exposed to conditions ideal for germination. These seeds exhibit dormancy, or a state of reduced metabolism in which growth and development do not occur.

Plant Behavioral Adaptations A tropism is a response in which a plant grows either toward or away from an environmental stimulus. Tropisms are slow responses. Phototropism – light is the stimulus, plant grow towards the light Gravitropism – gravity is the stimulus, roots grow down while shoots grow up from the seed Thigmotropism – response to touching a solid object, lets vines grow up a pole

Plant Behavioral Adaptations Nastic movements are responses to environmental stimuli but are independent of the direction of the stimuli. Nastic movements are faster than tropic. Thigmonastic movements occur in response to touch, such as the closing of the leaf trap of a Venus’ flytrap around an insect. https://www.youtube.com/watch?v=ktIGVtKdgwo