Primary Succession is when an ecological community experiences a community changing natural disaster (volcano, glacier, etc) primary succession starts from bare rock. Secondary succession starts from pre-existing soil, and occurs from a hurricane, deforestation, etc.
Directional selection is where one phenotype is favored, so an example would be "a population of madagascar hissing cockroaches suffers heavy predation from lizards. Because their heads are small, the lizards are unable to eat the very largest adult cockroaches, and instead prey upon small and medium sized adults, so as a result the large cockroaches are favored and live".
Meanwhile, disruptive selection is where both extreme phenotypes are favored, an example would be "a population of rabbits can have black fur, white fur or grey fur. This population of rabbits lives in an area of white rocks. When a local volcano erupts, black volcanic rock now dots the landscape amongst the white rocks. Now the black and white rabbits live longer because the black and white spots on the landscape camoflauge them. The two extreme phenotypes are being favored."
Answer:
The question lacks options, the options are:
A) All cells contain a nucleus.
B) All cells come from other living cells
C) All living organisms are made of one or more cells.
D) Cells are the basic unit of structure and function of all living things.
The answer is A
Explanation:
In 1830's, three scientists named; Mattias Schleiden, Theodor Schwann and Rudolph Virchow contributed to describing the basic properties of the cell, which they proposed in their so named CELL THEORY. This widely accepted cell theory has three components:
All living organisms are made up of one or more cells.
Cells are the basic and fundamental unit of life
All existing cells come from cells that have previously existed.
It was not proposed that all cells have a nucleus
