GMM Lesson 7 Notes: Successful Reproduction & Offspring
Background information:
●Sexual reproduction occurs in many multicellular organisms where the female gamete (egg cell) and male gamete (sperm) unite
●In plants, the female gamete is found in the ovule and the male gamete in pollen each with half the chromosomes needed to create an individual.
●Flowering plants are not able to move from one location to another so many utilize a pollinator to help sexual reproduction.
●The goal of sexual reproduction is for an individual to pass its genes on to the next generation so that they, in turn, can then pass the genes on, termed reproductive success.
●Seed dispersal can occur in several ways - gravity, wind, animals, mechanical propulsion and water.
Reading - Animal Behavior and Reproduction
●The cost of the peacock growing long, vibrant feathers could include a decrease in energy because most of its energy is utilized by the formation of the feathers, or the long feathers may increase the time it takes to fly away from a predator. The vibrant feathers can also make the male peacock a target for predators because their bright colors are more easily spotted in nature.
●A cardinal will swoop down to distract the snake, an action that could protect its young from being harmed.
●Mammals for example, have few offspring and parent for long periods of time to ensure that their offspring have a better chance of survival.
Reading The Wonder of Flowering Plants
●The male structures of the plant are called the stamen and the female parts are called the pistil.
●Perfect flowers have both the pistil and stamen within their flower. An imperfect flower has a pistil or stamen but not both.
●A plant would use its energy and resources to grow fruit so that its seeds are protected and able to be transported away from the parent plant. This provides a greater chance of the offspring surviving.
Investigation 7.1: investigation Flowers and their Pollinators
Flower/Plant / PollinatorPeruvian Lilies / Bee
Magnolia blossoms / Beetles
Travelers Palm / Lemur
Trumpet Flowers / Hummingbirds
Thistles / Butterflies
Saguaro Cactus Blossoms / Bats
Toetoe plants / Wind
Corpse Flowers / Carrion Flies
Pale Evening Primroses / Moths
●Pollen can move from flower to flower by pollinators such as wind, bees, animals, weather conditions
●Many flowers rely on multiple pollinators to increase the chance of a plant reproducing.
●Flowers are designed, with the stamen and pistil not able to touch, because this design promotes cross-pollination between two different plants. This then increases the genetic diversity in the DNA combinations. These different DNA combinations could help the species of plant better survive environmental changes or disease.
●Cross-pollination is more advantageous for plants because it promotes greater genetic diversity thanks to the numerous DNA combinations that can occur between separate parts of the same species.
●If bees or other pollinating species became extinct, we may not have as many fruits that we have now because these pollinators help to pollinate many crops and other foods that humans rely on.
●Flowers and their pollinators have mutualistic relationship. This means that both organisms benefit one another in some way. For example, flowers benefit by being pollinated and the animals benefits by being provided food.
Investigation 7.2: Seed Dispersal
●Types of seed dispersal:
●Gravity- seeds fall from tall plants then can be picked up by animals
●Wind- seeds have structures that help them glide or fly through the air. (maple & thistle)
●Animals- some seeds have fruits or seeds that attract animals. These animals collect and eat the fruit, digest the fruit and deposit the seed from their waste. (coclebur & pumpkin)
●Mechanical propulsion- some plants have mechanism by which they eject their seeds from a pod by force. (sicklepod)
●Water- some plants produce seeds that can float on the surface of the water. (sedge)
●Seeds can remain inactive or dormant for long periods of time. Once water is introduced to some seeds, the dormancy ends and the seed begins to grow into a plant. Some seeds can be activated by fire or a change in temperature.
●Seeds can be dispersed to new islands by wind or water. Often seeds are light enough to be carried by wind. Other seeds, such as coconuts, may float to a new island. Once an island is established, animals like birds, can bring seeds to the island vias their digestive systems.
●The reason people srape the bottoms of their shoes is so that a non-native species of plants does not enter the country.
Investigation 7.3: Successful Germination & Growth
●Germinate- to grow
●In order for a seed to grow, it must encounter the correct conditions.
●Ideal conditions for a plant to grow are water, loose fertile soil, suitable amount of space and appropriate temperature.
●If a maple seed landed next to the parent tree the seed may germinate but not grow well because the seedling and the parent plant would be competing for the same resources (water, soil, sunlight, space)
●If 20 seeds were planted in the same cup, some of the seeds would likely germinate but not grow well because they would be overcrowded and competing for the same resources.
●In the tropical rainforest, many plants grow on the branches of canopy trees. In order to grow, plants need sunlight to carry out photosynthesis. Sunlight can not travel to the rainforest floor because of the thick canopy cover, so several plants have adapted by growing in the upper areas of trees where light is plentiful.
Investigation 7.4: Flower Design
●The different colors on flower petals help to attract different pollinators to help them reproduce.
●Rainforest vs. desert: rainforest flowers are very diverse. Some flowers in a rainforest are more colorful to stand out among the dense green foliage. The flowers also need to be tough enough to withstand a lot of water and must have structure to prevent water from filling up the flower and destroying the reproductive structures within it. In the desert, many animals are nocturnal due to the intense heat. Desert flowers would be white to better attract pollinators who come out at night. The flower may also close during the day to prevent it from drying out.
●Many grassland flowers produce strong fragrances to attract pollinators. If a flower had a mutation in its DNA and did not produce the frangrance the plant most likely would not reproduce because it relies on attracting a pollinator. The plantmay have some success through self-pollination, but it is unlikely.
Reflecting on what you have done:
●If the bee population decreased...people across the world would be concerned about a decrease in the bee population because beese are one of the most common pollinators. Without pollination, plants cannot produce fruits. Without, fruits, farming and food production would decrease and the cost of food would increase.
●Some reasons for the decline of bees could be due to disease or insecticides.
●Behaviors and structures allow plants and animals to reproduce more successfully and better survive… many plants have both male and female reproductive structures within the flower that aid in reproduction, along with various shape, colors, and fragrances that attract various pollinators to assist in successful reproduction. Once the seeds are created many plants create a fruit around the seeds to help move the offspring away from the parent plant. In animals, many produce pheromones to attract a mate, while males display courtship behaviors to attract a mate. Once offspring are created, some animals provide parental care to better ensure the survival of their offspring.
Reading - Parental Care: A Worthwhile Investment
●Fitness- an individual has higher fitness with more offspring and as a result its genes are represented in the next generation to a greater degree than an individual with less surviving offspring.
●Some of the costs to caring for young are time for finding resources and increased vulnerability to predators. A benefit wouldbe the ability to attract future mates.