science 6 (all)

• Coral reefs are the largest ecosystem on earth found in the ocean
• Coral reefs support various communities including the coral reef, which is known as the "rain forest of the aquatic ecosystem"
• Coral reefs shelter different species of fish, invertebrates, phytoplankton, and zooplankton
• Phytoplankton serve as the producers in a coral reef, while zooplankton and other organisms eat the phytoplankton
• Coral reefs are usually found in tropical waters and have a wide range of colors
• Coral polyps build the reef by creating hard, shell-like substances called calcium carbonate that hardens to become limestone
• Filter feeders like mussels and clams live at the lower portion of the coral reef
• Herbivores, carnivores, and omnivores like sea urchins, barracudas, eels, crabs, and fishes are present in coral reefs
• Predation occurs when a predator like a barracuda eats a prey like a clownfish
• Competition can be seen in filter feeders such as annelid worms and molluscs
• Symbiotic relationships are evident in the coral reef
• Parasitism is seen between a pearl fish and a sea cucumber
• Commensalism is seen when barnacles attach themselves to a whale's body
• Kinds of reef:

  • Fringing reef: found close to the shore and around an island
  • Barrier reef: located at a far distance from an island with a lagoon in between
  • Atoll reef: circular reef formation located at a far distance from a sunken island with a lagoon between
• Mangrove swamps are found in estuaries where the river and the sea or ocean meet
• Mangrove swamps have brackish water and serve as breeding grounds for invertebrates and fishes
• Nutrients from the ocean, sea, and river flow through mangrove swamps, which have high levels of nutrients
• Dominant organisms in mangrove swamps are plants like bakawan, tangal, and busain
• Predation can be seen between oysters and zooplankton
• Parasitism is seen between starfish-eating oysters
• Commensalism is seen in snails attached to the trunk and roots of a mangrove plant
• Mutualism occurs between a crocodile and a bird
• Tropical rain forests are terrestrial ecosystems and considered Earth's oldest living ecosystem
• Tropical rain forests are situated near the equator, humid, and warm
• They receive abundant rainfall every year
• Tropical rain forests have the highest number of organisms among terrestrial ecosystems
• Predation is present in snakes preying on small animals like frogs, birds, and rats
• Competition is evident among big trees competing for sunlight and nutrition
• Parasitism occurs between a deer and a tick
• Commensalism is seen in big trees and epiphytes
• Mutualism is present in the termite and flagella called Trichonympha
• Friction is a contact force that exists when one surface slides over another
• Friction is affected by the irregularities in the surfaces of two objects in contact during sliding or rolling
• Friction resists motion and produces heat
• Smooth surfaces provide less friction than rough surfaces
• Types of Friction:

  • Static friction keeps an object at rest until a force greater than the maximum possible static friction is applied
  • Kinetic friction slows down a moving object and can be sliding, rolling, or air friction
  • Sliding friction acts on dry, solid objects sliding on a surface
  • Rolling friction slows down the motion of wheels on a solid surface and is weaker than sliding and static friction
  • Air friction acts on objects moving through the air and is affected by the surface area of the object
• Friction may be increased by increasing the roughness of the surface and decreased by making the surface smooth with lubricants like wax and oil
• Gravity pulls objects toward the center of the Earth and is the only downward force acting on every object
• Gravity keeps our feet on the ground and prevents us from floating into space
• A 1 kg rock weighs 9.8 newtons on Earth and 1.62 newtons on the moon