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All the individuals of a species living within a specific area are collectively called a population    . For example, a forest may include many pine trees. All of these pine trees represent the population of pine trees in this forest. Different populations may live in the same specific area. For example, the forest with the pine trees includes populations of flowering plants and also insects and microbial populations. A community    is the sum of populations inhabiting a particular area. For instance, all of the trees, flowers, insects, and other populations in a forest form the forest’s community. The forest itself is an ecosystem. An ecosystem    consists of all the living things in a particular area together with the abiotic, non-living parts of that environment such as nitrogen in the soil or rain water. At the highest level of organization ( [link] ), the biosphere    is the collection of all ecosystems, and it represents the zones of life on earth. It includes land, water, and even the atmosphere to a certain extent.

Art connection

A flow chart shows the hierarchy of living organisms. From smallest to largest, this hierarchy includes: (1) Organelles, such as nuclei, that exist inside cells. (2) Cells, such as a red blood cell. (3) Tissues, such as human skin tissue. (4) Organs such as the stomach make up the human digestive system, an example of an organ system. (5) Organisms, populations, and communities. In a forest, each pine tree is an organism. Together, all the pine trees make up a population. All the plant and animal species in the forest comprise a community. (6) Ecosystems: the coastal ecosystem in the Southeastern United States includes living organisms and the environment in which they live. (7) The biosphere: encompasses all the ecosystems on Earth.
The biological levels of organization of living things are shown. From a single organelle to the entire biosphere, living organisms are parts of a highly structured hierarchy. (credit “organelles”: modification of work by Umberto Salvagnin; credit “cells”: modification of work by Bruce Wetzel, Harry Schaefer/ National Cancer Institute; credit “tissues”: modification of work by Kilbad; Fama Clamosa; Mikael Häggström; credit “organs”: modification of work by Mariana Ruiz Villareal; credit “organisms”: modification of work by "Crystal"/Flickr; credit “ecosystems”: modification of work by US Fish and Wildlife Service Headquarters; credit “biosphere”: modification of work by NASA)

Which of the following statements is false?

  1. Tissues exist within organs which exist within organ systems.
  2. Communities exist within populations which exist within ecosystems.
  3. Organelles exist within cells which exist within tissues.
  4. Communities exist within ecosystems which exist in the biosphere.

The diversity of life

The fact that biology, as a science, has such a broad scope has to do with the tremendous diversity of life on earth. The source of this diversity is evolution    , the process of gradual change during which new species arise from older species. Evolutionary biologists study the evolution of living things in everything from the microscopic world to ecosystems.

The evolution of various life forms on Earth can be summarized in a phylogenetic tree ( [link] ). A phylogenetic tree    is a diagram showing the evolutionary relationships among biological species based on similarities and differences in genetic or physical traits or both. A phylogenetic tree is composed of nodes and branches. The internal nodes represent ancestors and are points in evolution when, based on scientific evidence, an ancestor is thought to have diverged to form two new species. The length of each branch is proportional to the time elapsed since the split.

This phylogenetic tree shows that the three domains of life, bacteria, archaea and eukarya, all arose from a common ancestor.
This phylogenetic tree was constructed by microbiologist Carl Woese using data obtained from sequencing ribosomal RNA genes. The tree shows the separation of living organisms into three domains: Bacteria, Archaea, and Eukarya. Bacteria and Archaea are prokaryotes, single-celled organisms lacking intracellular organelles. (credit: Eric Gaba; NASA Astrobiology Institute)

Questions & Answers

can i get a broader difference between inductive reasoning and deductive reasoning
Daniel Reply
what are the types of tissues and there functions
Daniel
what is signal cascade?
nur Reply
it is the process by which plants produce their fo
Getabalew Reply
what are the substrates of this process
Fiko
definition of photosynthesis
Fiko Reply
it is simply the process by which plants get there food from the sun through the use of chlorophyll
Daniel
what are the advantages and disadvantages of external and internal fertilization
Mohd Reply
which type of blood group can be tranfer easily after Accidents
Durgesh Reply
O positive cause it is a general donor
Daniel
It can give to other blood group except O negative that can only get from O negative
Daniel
which is the polygonum type of embryo sac in angiosperms
Madhura Reply
Describe how hormones regulate blood pressure, blood volume, and kidney function
junius Reply
2 Positive water potential is placed on the left side of the tube by increasing Ψp such that the water level rises on the right side. Could you equalize the water level on each side of the tube by adding solute, and if so, how?
Sarah Reply
where are the enzymes required for electron transport system located
Madhura
plant and animal cell
Oyedeji Reply
what plant and animal cell
PAvan
plant cell has a definite shape whilst the animal cell has indefinite shape
Owusu
what are the type of cell
abiola Reply
Poukaryotic cell and euakaryotic cell
Smile's
prokaryotes don't have well delet nucleus while Euler have well developed nucleus
Durgesh
Which of the following is considered a keystone species? Deer, Beaver, Elk or Wolves
Nicole Reply
Origin and Diversity of higher plants
Gideon Reply
explain the reason why the impudent and excessive use of antibiotics could be potentially harmful to the user.
Alfred Reply
diseases gain antibiotic resistance from the antibiotic if often used.
Jerome
what is mean by serum
vasant Reply

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Source:  OpenStax, Biology. OpenStax CNX. Feb 29, 2016 Download for free at http://cnx.org/content/col11448/1.10
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