These are carnivorous plants in the genus Cephalotus (Australian)
Many flowering plants have evolved ways to attract pollinators. Carnivorous plants just went one step further. . . Carnivorous plants have survived in laboratories without eating meat. The tropical genus Nepenthes has some vines that can grow 10 m long (picture is of a Nepenthes trap).
When species have evolved similar traits but are not related, it is called “convergent evolution”. Carnivory in plants is an example of convergent evolution.
When species have evolved similar traits but are not related, it is called “convergent evolution”. Carnivory in plants is an example of convergent evolution.
Carnivorous plants have adapted to the nutrient poor environments of some wetlands and have the ability to get their nutrients from meat-sources; thus, they have a competitive advantage over non-carnivorous plants ONLY IN NUTRIENT POOR HABITATS. In habitats with more nutrients, non-carnivorous plants do not have to put so much energy in specialized structures to capture prey, so they have a competitive advantage over carnivorous plants.
The first picture is a close up of a carnivorous plant leaf. The flies are stuck in the glandular hairs. The second picture is of the freshwater bladderwort plant ( Utricularia ) that captures small water animals in its bladders. Nepenthes is the tropical genus that small birds and rodents have been found in. However, this is not common at all and the birds and rodents must have been very sick to not be able to get out. Some plants have insects that live on them and kill the smaller insects that get trapped in the sticky hairs. These bigger insects excrete on the plant and the plants absorb it. But the weirdest of all has to be the plants that absorb bird excrement!!
The first picture is an example of an active trap. It is a Venus fly-trap ( Dionaea ), which has a trap that closes shut quickly when the trigger hairs are touched. The cells on the inside of the trap become limp and the leaf closes. The second picture is a passive trap (sticky, glandular hairs) of a sundew ( Drosera ).
Top left: A close-up of an african Drosophyllum (sundew) . It has sticky, glandular hairs that insects get trapped in and the plants slowly digests them. When the insect gets trapped, the tentacles bend towards the prey due to irregular cell growth. Top right: Pinguicula reticulata , a small plant with sticky, glandular hairs. Bottom left: Sarracenia alabamensis , a species found in Alabama, has a pitfall trap. The reddish color on the plant attract insects to the trap. They walk in and fall down the trap, which has waxy walls and hairs pointing downwards, and they can’t get out. They drown in the digestive juices at the bottom of the trap. Bottom right: Utricularia (the freshwater carnivorous plant) has an active trapping system, made up of small bladder-like structures (common name is bladderwort) that it can suck prey into in about 1/30 of a second. **Next show the videoclip from the internet of the venus fly-trap ( Dionaea ) capturing prey and the short animation clips of Drosera, Utricularia and Drosophyllum.
The picture is the partially digested contents of insects in a carnivorous plant. They produce very mild digestive enzymes that slowly digest the animals that they capture. Bacteria often live on the carnivorous plant and they secrete their own digestive enzymes (the plant sometimes also has its own enzymes). This is an example of symbiosis, because both the bacteria and plant benefit (bacteria gets food and a place to live and the plant gets help digesting).
The decaying plants release acidic compounds, which accumulate in the water. There is no outflow of water, so these acidic compounds stay in the water and make it acidic (lower the pH). Two things happen when the pH of the water is lowered: 1) Microorganisms that aid in decomposition cannot function, so dead plants do not decay (they just sit there). With such low decomposition, there are few nutrients available. 2) When soil is acidic, it is difficult for plants to assimilate nutrients, so the few nutrients that are there, the plants cannot take up. The first photo is of a Sarracenia (pitcher plant) bog, the second is of a rocky mountain wetland.
Only 3-5% of carnivorous plant habitat remains! Many habitats, especially in Florida, need periodic fires to keep out species that don’t belong and regenerate species that do belong. Water pollution can kill carnivorous plants. When we take too much groundwater (for drinking, industrial and agricultural uses) this can lower the water table, which can take the water out of wetlands and kill the plants that need water to survive. Carnivorous plants are very beautiful and intriguing plants, so people often collect them from the wild. This hurts wild populations and has even put some species on the endangered species list. All Sarracenia , Nepenthes and Dionaea muscipula (the venus fly trap) are on the endangered or threatened species list. This means that it is illegal to kill (or take) any part of these plants. You can be fined $1000’s of dollars for harming them or taking them. If you are interested in owning some carnivorous plants, there are many nurseries that sell plants that were not poached from the wild. The picture is of a drained wetland in Florida.
Answers: 1) They can attract, capture, kill and digest animals (insects) 2) Non-carnivorous plants can attract insects (for pollination) 3) No-they have been grown in labs and survived with no meat. 4) Everywhere except Antarctica (most abundant in Australia, SE Asia, and North America). 5) 600 species and sub-species: No, they are not all related, they all separately evolved the trait of carnivory (convergent evolution).
Nutrient poor wetlands The lack of nutrients available in the soil The decaying plants release acidic compounds, which accumulate in the water. There is no outflow of water, so these acidic compounds stay in the water and make it acidic (lower the pH). Two things happen when the pH of the water is lowered: 1) Microorganisms that aid in decomposition cannot function, so dead plants do not decay (they just sit there). With such low decomposition, there are few nutrients available. 2) When soil is acidic, it is difficult for plants to assimilate nutrients, so the few nutrients that are there, the plants cannot take up. 4) Because they do not have to put energy into specialized structures like carnivorous plants do.
Insects, spiders and the aquatic plants eat small animals, fish and mosquito larvae. Amphibians (frogs), birds and rodents Active and passive Active: Utricularia (the bladderwort) has small bladders that suck prey in. The venus fly trap ( Dionaea ) has a trap that closes very quickly when an insect touches the trigger hairs. The cells on the inside of the trap become limp and the leaf closes. Passive: The pitcher plant has a pitfall trap that insects crawl in and can’t get out because of the waxy coating and hairs pointing downwards. Many carnivorous plants have glandular hairs that insects get stuck in and then the plant digests them.
They can attract, capture, kill and digest animals (insects). Non-carnivorous plants attract insects for pollination. 600 species and sub-species that are not all related (convergent evolution). Found most commonly in nutrient poor wetlands everywhere except Antarctica. Lack of nutrients.
Insects and spiders. Less common are amphibians, birds and rodents. Some capture prey for insects to eat and eat the insect feces, some eat bird feces. Active and passive traps. Some secrete digestive enzymes, some use enzymes and bacteria to help them digest (symbiosis). Humans have drained wetlands (destroyed habitat), suppressed fire (detrimental to many carnivorous plant habitats around the world), polluted the water (kills the plants), used too much water which lowered the water table, and poached plants (many species on endangered species list).
Transcript of "Carnivorous plants ppt les 3"
Carnivorous Plants:Science Fiction or Science??
What in the world is a carnivorousplant? Must be able to attract, capture and kill animals (mostly insects) Also must digest the animal Can survive without eating meat, though. Most are small (<1 m tall) but one vine species can grow to be 10 m long
Where in the world can I find these plants? Everywhere except Antarctica!! More abundant in Australia, southeast Asia and North America Even Alachua county has them!! 600 species and sub-species, but not all related to each other
Where in the world can I find these plants? Hundreds of species of plants from several genera are carnivorous. Carnivorous plants are found all over the world. Their habitats range from grasslands to swamps to under water, from civilization to the jungles of the Amazon.
Why aren’t all plants meat-eaters? Carnivorous plants have an advantage over non- carnivorous plants in nutrient poor habitats In habitats with more nutrients, non-carnivorous plants do better because they do not have to put energy into special structures.
What animals do they eat? Mostly Insects and spiders (gnats, flies, moths, wasps, spiders, butterflies, beetles and ants) Freshwater species eat small water animals and fish and mosquito larvae Some capture small amphibians (frogs) and small birds and rodents have been found in some tropical species!! Some species even eat insect and bird excrement!!
How do these plants capture prey? Can be sweet-smelling or brightly colored to attract prey to their trap There are 2 types of traps Active: Use rapid movement (ex. Venus fly- trap, Utricularia) Passive: sticky hairs or a long tube with hairs that trap prey
How do they digest their prey? Most produce digestive enzymes Some rely on bacteria Some use both bacteria and digestive enzymes
What habitat do they live in? The genus Utricularia is aquatic (freshwater) Mainly found in nutrient poor wetlands (ex. Bogs) Decaying plants release acidic compounds Microorganisms cannot function Difficult for plants to get nutrients from acidic soil
How do we affect carnivorous plants Only 3-5% of carnivorous plant habitat left! Draining wetlands For roads, homes, stores and water Suppressing fire Many ecosystems need fire to stay healthy Pollution from homes and agriculture Gets into water and destroys plants Poaching the plants: Many are endangered.
Are The Plants Hard to Grow? Carnivorous plants can be easy to grow. They can be cultivated in a greenhouse. You can grow some varieties in your house as house plants!
How do Carnivorous plants get theirenergy? They get their energy the same way the other plants do... Photosynthesis
Why do Carnivorous plants eat insectsand other small animals? They eat insects and other small animals because they live in places where the soil is low in nutrients. Carnivorous plants get the needed nutrients from their “PREY”.
Catching the insect The actual traps are located on the plants leaves They attract their victims with a scent reminiscent of food and a safe landing place As soon as the insect settles, the leaf tips spring instantly with lightning speed and within seconds the insect is trapped inside the two halves of the leaf There is a second where the plant tests what it has caught using its sensory glands on the surface of its lobes If the prey contains protein, the trap clothes fully and the digestion begins
The Digestion Process Once the insect has been caught, it is slowly dissolved by digestive fluids produced by the plant After many days, all that is left is the insect’s exoskeleton, the hard outer casing of the body The rest has been absorbed by the plant
Vitamin Tablets Carnivorous plants, like any other plant, also use the process of photosynthesis to make their own food The insects they catch are only used as dietary supplements Like the equivalent of vitamin tablets for plants Many plants need this extra source of food as they grow in waterlogged ground where the soil is lacking in nutrients and other essential nutrients
Pitfall Traps(pitcher plant) The pitcher plant is basically a slippery leaf wrapped into a tube shape that contains a pool of digestive enzymes at the bottom.
Pitfall Trap (Cobra Lily) Most Pitfall Traps have the opening on the top of the plant, the Cobra Lily has an opening on the bottom. When an insect flies into it, it has “windows” that let light in but not insects out. The insects are attracted to the light but cant get out.
Fly Paper traps(sundew) Fly Paper traps are coated with a sticky substance called “mucilage". When an insect lands on the plant it sticks to it, after a while the plant will curl around it and digest it.
Snap traps(Venus fly trap) Venus Fly Trap has small trigger hairs on the inside, so if an insect lands on it and triggers only one hair and flies off its lucky but if it triggers more than one it will cause its own doom.
Bladder traps(Bladderwort)The Bladderwort is like an under water Venus FlyTrap. The bladders suck in and trap water insects.
Let’s Review. . .1) What are the 4 traits of a carnivorous plant? They attract, capture, kill and digest animals2) Do non-carnivorous plants share any of these traits? Non-carnivorous plants can attract insects3) Do they need to eat meat to survive? No-they have been grown in labs without meat4) Where in the world can you find these plants? Everywhere except Antarctica5) How many species are there? Are they all related? 600 species and sub-species; they are not all related (convergent evolution)
Let’s Review. . . 1. What is the most common habitat of carnivorous plants? Nutrient poor wetlands. 2. What feature of their habitat allowed them to evolve carnivory? The lack of nutrients available in the soil. 3. Why does the habitat have this feature? pH of water is low, so bacteria cannot help decompose plants and plants cannot take up nutrients as easily. 4. Why do non-carnivorous plants do better in habitats with more nutrients? Because they do not have to put energy into special structures to capture prey like carnivorous plants do.
Let’s Review . . . 1. What do carnivorous plants commonly eat? Insects, spiders and aquatic plants eat small animals, fish and mosquito larvae. 2. Name 3 less common things they have been found to eat. Amphibians, birds and rodents 3. What are the two types of traps they use to catch their prey? Active and passive 4. Name a variation of each type of trap. Active: bladderwort (Utricularia), venus fly trap (Dionaea). Passive: pitcher plant has a pitfall trap; most carnivorous plants have sticky hairs.
Final Review and Wrap-Up 1) What are the 4 traits of a carnivorous plant? Do non-carnivorous plants have any of these traits? Attract, capture, kill and digest animals. Yes, many plants attract insects for pollination. 2) How many species are there of carnivorous plants? Are they all related? 600 species and sub-species that are not all related (convergent evolution) 3) In what habitats and parts of the world are they found? Found mostly in nutrient poor wetlands everywhere except Antarctica. 4) What feature of their habitat allowed them to evolve carnivory? Lack of nutrients
Final Review and Wrap-Up cont… 1) What are some of their common prey species? Some less common ones? Insects and spiders. Less common are amphibians, birds and rodents. 2) What are the two ways they capture their prey? Active and passive traps. 3) How do they digest their prey (hint: what do some use to help them digest?)? Some secrete digestive enzymes, some use enzymes and bacteria to help them digest (symbiosis). 4) How have humans affected carnivorous plant populations and their habitat? Humans have drained wetlands, suppressed fire, polluted water, used too much water and poached plants.
Assignment Draw your own carnivorous plant using only plant parts.
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