Which One Of The Following Is Defining Characteristics Of Animals But Not Of Plants

Listing the defining characteristics of biological life

Biology is the science that studies life, just what exactly is life? This may sound similar a featherbrained question with an obvious response, but it is not always easy to ascertain life. For example, a branch of biology called virology studies viruses, which exhibit some of the characteristics of living entities but lack others. It turns out that although viruses tin set on living organisms, cause diseases, and even reproduce, they do not run into the criteria that biologists utilize to define life. Consequently, virologists are not biologists, strictly speaking. Similarly, some biologists study the early molecular evolution that gave rise to life; since the events that preceded life are not biological events, these scientists are besides excluded from biology in the strict sense of the term.

From its earliest beginnings, biology has wrestled with these questions: What are the shared backdrop that brand something "live"? And in one case we know something is alive, how practice nosotros find meaningful levels of organization in its structure?

Learning Objectives

• List the properties of life
• Order the levels of organization of living things

Properties of Life

All living organisms share several central characteristics or functions: order, sensitivity or response to the environment, reproduction, growth and development, regulation, homeostasis, and energy processing. When viewed together, these characteristics serve to ascertain life.

Society

Figure 1. A toad represents a highly organized construction consisting of cells, tissues, organs, and organ systems.

Organisms are highly organized, coordinated structures that consist of ane or more cells. Even very simple, single-celled organisms are remarkably complex: within each jail cell, atoms brand up molecules; these in turn make upwards cell organelles and other cellular inclusions.

In multicellular organisms (Effigy 1), similar cells course tissues. Tissues, in turn, collaborate to create organs (torso structures with a distinct function). Organs work together to class organ systems.

Sensitivity or Response to Stimuli

Organisms reply to diverse stimuli. For example, plants can curve toward a source of lite, climb on fences and walls, or respond to touch (Effigy 2).

Effigy 2.The leaves of this sensitive plant (Mimosa pudica) volition instantly droop and fold when touched. After a few minutes, the plant returns to normal. (credit: Alex Lomas)

Even tiny bacteria can move toward or away from chemicals (a process calledchemotaxis) or low-cal (phototaxis). Movement toward a stimulus is considered a positive response, while movement away from a stimulus is considered a negative response.

Watch this video to encounter how plants respond to a stimulus—from opening to light, to wrapping a tendril around a branch, to capturing prey.

Reproduction

Single-celled organisms reproduce past first duplicating their DNA, and then dividing it equally every bit the cell prepares to divide to class 2 new cells. Multicellular organisms ofttimes produce specialized reproductive germline cells that will grade new individuals. When reproduction occurs, genes containing Deoxyribonucleic acid are passed along to an organism'southward offspring. These genes ensure that the offspring volition belong to the aforementioned species and volition accept similar characteristics, such as size and shape.

Growth and Evolution

Figure 3. Although no ii look alike, these puppies have inherited genes from both parents and share many of the same characteristics.

Organisms grow and develop post-obit specific instructions coded for by their genes. These genes provide instructions that volition direct cellular growth and development, ensuring that a species' young (Figure 3) will grow upwardly to exhibit many of the same characteristics as its parents.

Regulation

Even the smallest organisms are circuitous and require multiple regulatory mechanisms to coordinate internal functions, respond to stimuli, and cope with environmental stresses. 2 examples of internal functions regulated in an organism are nutrient transport and blood flow. Organs (groups of tissues working together) perform specific functions, such as carrying oxygen throughout the body, removing wastes, delivering nutrients to every cell, and cooling the torso.

Homeostasis

Figure 4. Polar bears (Ursus maritimus) and other mammals living in ice-covered regions maintain their torso temperature by generating heat and reducing rut loss through thick fur and a dense layer of fat under their peel. (credit: "longhorndave"/Flickr)

In order to function properly, cells need to have appropriate atmospheric condition such equally proper temperature, pH, and appropriate concentration of diverse chemicals. These atmospheric condition may, still, change from i moment to the adjacent. Organisms are able to maintain internal atmospheric condition within a narrow range nigh constantly, despite environmental changes, throughhomeostasis (literally, "steady land")—the ability of an organism to maintain constant internal conditions. For example, an organism needs to regulate body temperature through a process known as thermoregulation. Organisms that live in cold climates, such equally the polar behave (Figure iv), take torso structures that assist them withstand low temperatures and conserve body heat. Structures that aid in this blazon of insulation include fur, feathers, blubber, and fat. In hot climates, organisms have methods (such every bit perspiration in humans or panting in dogs) that assist them to shed excess body heat.

Energy Processing

All organisms apply a source of energy for their metabolic activities. Some organisms capture energy from the sun and convert it into chemical energy in food (photosynthesis); others utilize chemical energy in molecules they take in as food (cellular respiration).

Figure 5. The California condor (Gymnogyps californianus) uses chemical energy derived from nutrient to power flight. California condors are an endangered species; this bird has a wing tag that helps biologists identify the individual.

Levels of Organization of Living Things

Living things are highly organized and structured, following a hierarchy that can be examined on a calibration from small-scale to large. The cantlet is the smallest and almost central unit of measurement of matter. Information technology consists of a nucleus surrounded by electrons. Atoms form molecules. A molecule is a chemical structure consisting of at least two atoms held together by ane or more chemical bonds. Many molecules that are biologically important are macromolecules, large molecules that are typically formed by polymerization (a polymer is a large molecule that is made by combining smaller units called monomers, which are simpler than macromolecules). An example of a macromolecule is deoxyribonucleic acid (DNA) (Figure 6), which contains the instructions for the construction and operation of all living organisms.

Effigy six. All molecules, including this DNA molecule, are composed of atoms. (credit: "brian0918″/Wikimedia Eatables)

Some cells contain aggregates of macromolecules surrounded by membranes; these are calledorganelles. Organelles are minor structures that exist within cells. Examples of organelles include mitochondria and chloroplasts, which carry out indispensable functions: mitochondria produce energy to power the prison cell, while chloroplasts enable green plants to utilize the energy in sunlight to brand sugars. All living things are made of cells; the cell itself is the smallest fundamental unit of structure and part in living organisms. (This requirement is why viruses are non considered living: they are not made of cells. To brand new viruses, they have to invade and hijack the reproductive mechanism of a living jail cell; but and so tin they obtain the materials they need to reproduce.) Some organisms consist of a single cell and others are multicellular. Cells are classified as prokaryotic or eukaryotic. Prokaryotes are single-celled or colonial organisms that do non have membrane-jump nuclei or organelles; in contrast, the cells of eukaryotes practice have membrane-bound organelles and a membrane-bound nucleus.

In larger organisms, cells combine to maketissues, which are groups of similar cells conveying out similar or related functions. Organs are collections of tissues grouped together performing a common function. Organs are present not but in animals but also in plants. An organ organization is a college level of organization that consists of functionally related organs. Mammals have many organ systems. For instance, the circulatory system transports blood through the body and to and from the lungs; it includes organs such as the center and claret vessels. Organisms are private living entities. For example, each tree in a forest is an organism. Single-celled prokaryotes and single-celled eukaryotes are likewise considered organisms and are typically referred to as microorganisms.

All the individuals of a species living within a specific area are collectively called apopulation. For example, a forest may include many pine trees. All of these pino trees represent the population of pine trees in this forest. Different populations may live in the same specific area. For example, the wood with the pine trees includes populations of flowering plants and also insects and microbial populations. A customs is the sum of populations inhabiting a item area. For case, all of the copse, flowers, insects, and other populations in a forest form the forest'south community. The forest itself is an ecosystem. An ecosystem consists of all the living things in a particular expanse 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 (Effigy 7), the biosphere is the collection of all ecosystems, and information technology represents the zones of life on earth. It includes land, water, and even the atmosphere to a certain extent.

Practice Question

From a single organelle to the unabridged biosphere, living organisms are parts of a highly structured hierarchy.

Figure 7. The biological levels of organization of living things are shown. From a unmarried 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 Establish; 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 past "Crystal"/Flickr; credit "ecosystems": modification of piece of work past United states Fish and Wildlife Service Headquarters; credit "biosphere": modification of piece of work by NASA)

Which of the following statements is false?

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

Show Reply

Statement b is false: populations exist within communities.

Cheque Your Understanding

Reply the question(s) beneath to run across how well you sympathize the topics covered in the previous section. This short quiz doesnon count toward your grade in the form, and you tin retake it an unlimited number of times.

Use this quiz to check your agreement and decide whether to (ane) written report the previous section further or (2) motion on to the next department.

Source: https://courses.lumenlearning.com/suny-wmopen-biology1/chapter/the-characteristics-of-life/

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