Ques & Ans: A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. Such species are described as playing a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community. A keystone species is a plant or animal that plays a unique and crucial role in the way an ecosystem functions. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether.

Answer this question based on the passage: a species that has an essential role in maintaining ecosystem structure is called a?
A keystone species

Stream of consciousness: The important part for answering this question is: Such species are described as playing a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community.

Ques & Ans: Context: The census in the United Kingdom is decennial, that is, held every ten years, although there is provision in the Census Act 1920 for a census to take place at intervals of five years or more. There have only been two occasions where the census has not been decennial: There was no census in 1941 due to the war; and a mini-census using a ten percent sample of the population was conducted on 24 April 1966. There are actually three separate censuses in the United Kingdom-in England and Wales, Scotland, and Northern Ireland, although they are often coordinated. From 1821 until 1911, the census included the whole of Ireland.

Question: how often do we have a census in the uk?
every ten years

Stream of consciousness: To answer the question, consider the following: The census in the United Kingdom is decennial, that is, held every ten years, although there is provision in the Census Act 1920 for a census to take place at intervals of five years or more.

Ques & Ans: The GCA was signed into law by President Lyndon B. Johnson on October 22, 1968, and is Title I of the U.S. federal firearms laws. The National Firearms Act of 1934 (NFA) is Title II. Both GCA and NFA are enforced by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF).

Based on this passage, who signed the gun control act of 1968?
President Lyndon B. Johnson

Stream of consciousness:
To answer the question, consider the following: The GCA was signed into law by President Lyndon B. Johnson on October 22, 1968, and is Title I of the U.S. federal firearms laws.