Simple handwashing is more than enough to stop the spread of infectious diseases. The hands play a major role in spreading pathogens because it can come into contact with infected surfaces. Make sure to wash your hands especially when they get soiled or before you eat or drink.
Answer:
Option A, keystone species
Explanation:
Keystone species are responsible for controlling any species from becoming dominant over all other species. The keystone species are found at the top of all the energy pyramids and food chains.
They control the explosion of population of prey and hence regulate the overall ecological diversity.
Some common example of keystone species is as follows –
Bison, prairie dog, large mammalian predators,
Hence, option A is correct
Answer: Option C - decomposers; they return biotic material to the abiotic component of the Earth
Explanation:
Decomposers are also known as SAPROPHYTES. They feed on and break down dead and decaying remains of plants and animals, thus enabling the release of certain compounds like ammonia, methane gas etc into the environment that then enrich/improve the soil fertility.
Answer: the atoms are istopes
Explanation: