Untitled

Introduction to Biology

• Biology comes from the Greek words "bios", meaning life, and "logos", meaning science.
• Biology is the scientific study of all living things, known as organisms.
• Organisms include bacteria, protists, fungi, plants, and animals.

Defining Life

• Life has many different forms and varieties on Earth.
• Humans share the planet with about 8.7 million different forms of life.
• Organisms, or living things, have different behaviors than humans.
• The Antarctic blue whale is the largest animal, weighing up to 400,000 pounds and reaching 98 feet in length.
• The smallest adult insect is a parasitic wasp called Dicopomorpha echmepterygis, often called fairyflies, the males are wingless, blind and measure only 0.005 inches long.
• The lifespan of some bacteria is 15 minutes, while some pine trees can live as long as ten generations of humans.
• Living and non-living things are made up of chemical elements and follow the same laws of chemistry and the same physics laws.
• Organisms can be distinguished by how they obtain their food.
• Fungi digest their food externally through absorption.
• Sunflowers make their food through photosynthesis.
• Snow geese ingest their food.

Levels of Biological Organization

• Atoms are the basic units of matter.
• Molecules are clusters of atoms.
• Organelles are membrane-bound structures within cells that perform specific jobs.
• The cell is the simplest entity of life that contains life's properties.
• Tissues are groups of similar cells that perform specific functions in an organism.
• Organs are structures composed of two or more tissues that perform specialized functions.
• Organ systems have specific functions and are composed of organs that carry out a particular function within an organism.
• An organism is an individual living thing that can react to stimuli, reproduce, grow, and maintain homeostasis.
• A population consists of all individuals of a particular species that interbreed within a specific area.
• A community is the array of organisms with different populations living in a particular ecosystem.
• An ecosystem consists of all the organisms and communities living in a particular area.
• The biosphere includes all of the environments on Earth that support life.

Acquiring Materials, Energy, and Homeostasis

• Food offers compounds utilized as constituents or for energy
• Energy is the ability to do work.
• Cells use nutrient molecules and perform a sequence of chemical reactions through metabolism.
• The ultimate source of energy for all life on Earth is the sun.
• Plants and other organisms capture solar energy and utilize photosynthesis to transform it into chemical energy.
• An organism's ability to maintain biological balance is called homeostasis.
• Control mechanisms help maintain physiological factors such as temperature, moisture level, and acidity within a tolerable, for organisms limits.
• When blood sugar levels drop from not eating, the liver releases stored sugar.

Behavior of Living Things

• Multicellular organisms can manage complex responses unlike unicellular organisms.
• The ability to respond often results in movement, like leaves turning towards the sun.
• The behavior of an organism allows it to maintain homeostasis and search and compete for energy, nutrients, shelter, and mates.

Reproduction of Living Things

• Life comes only from life
• Every kind of living things can reproduce and create another organism similar to itself.
• Bacteria and protists reproduce by splitting in two.
• Most multicellular organisms reproduce through the fertilization of a sperm and an egg from another partner to form an embryo.
• Many cell divisions take place, and the organism becomes an adult.
• Genes are given to the next generation when living things reproduce.
• DNA can undergo mutations that may be passed on to the next generation, this creates diversity of life.

Adaptation and Biodiversity

• Adaptation refers to modifications that help organisms be better able to live in a particular environment.
• Penguins adapted to their aquatic existence using extra layer of short and thick feathers, they also slide on their bellies across the ice to conserve energy.
• Camels have many adaptive traits in the desert, which include wide feet, long eyelashes, and slit nostrils.
• The unity of all living things indicates that all organisms came from a common ancestor; the first cell.

Organizing Diversity

• Taxonomy identifies and groups organisms according to specific rules.
• The general classification categories include domain, kingdom, phylum, class, order, family, genus, and species.
• The definition of species is a group of individuals that interbreed.
• Species that are placed within one genus share specific characteristics while species put in the same family share only normal characteristics.

Linnaean Taxonomy

• It was believed that all organisms should have names in the seventeenth century.
• Carolus Linnaeus developed binomial nomenclature between 1707-1778 and each species receives a two-part name.
• Two different species of lily include Lilium canadense and Lilium bulbiferum.
• The first word is the genus.
• The second word refers to one species inside that genus.
• Scientific names are in italics; the genus is capitalized the species is not.
• Both names are underlined separately when handwritten.
• The specific epithet itself gives no meaning, the same as a house number without a street name.
• Scientific names are derived in several ways.
• Descriptive scientific names are in nature; Acer rubrum for the red maple.
• Geographic descriptions, such as Alligator mississippiensis might include names, for the American alligator.
• eponyms (named after someone) may also be included in scientific names such owl mite Strigophilus garylarsonii.
• Why do organisms have scientific names, and why do scientists use Latin rather than common names?
• Common names vary from country to country because of different languages.
• When scientists from around the world use the same scientific binomial name, they know they are all referring to the same organism.
• Around 30 million species now live on Earth.
• the task of naming and identifying all the species of the world is continuing.
• The most recent and efficient way of identifying species is based on their DNA.
• This identification method was found satisfactory for identifying mosquito species in India.

Linnaean Classification Categories

• In classification, a domain is from species and below only to the rank of genus.
• The taxonomist Aristotle divided living things into groups.
• Organisms in larger groups, were classified down a size scale.
• Ray created a more natural system, grouping animals and plants to how they interconnected.
• Linnaeus used differences in flower parts to categorize them.
• Nowadays, taxonomists use species, categories,genus, family, order, class, phylum and kingdom.
• A higher category or domain has been added to this list for bacteria, Archea, and Eucaria respectively.
• the order goes the higher the category, the more inclusive it becomes, this is a hierarchy of categories.
• To say that the items are nested is an alternative statement.
• A domain contains many kingdoms and kingdoms contain many classes.
• Organisms in a domain share some characteristics, domain those in same group have quite similar traits.
• The classification categories subdivide into three more categories, which are superorder, order, suborder, and infraorder.

Organizing Domain Diversity

• Biochemical evidence suggests that there are only three domains; Bacteria, Archaea, and Eukarya.
• Bacteria and Archaea evolved from a common ancestor after life began.
• They are prokaryotes, which lack a membrane bound nucleus for encoding information unlike the eukaryotes in the domain Eukarya.
• Archaea's membranes and cell walls are composed of chemicals that are more similar to eukaryotes compared to that of bacterial.

Three-Domain System

• A domain known as the bacteria are diverse and profuse and are found worldwide.
• Bacteria biochemically range from each other.
• All forms of nutrition are found among bacteria.
• Heterotrophic bacteria are beneficial because they break down organic remains within ecosystems.
• Like bacteria, archaea are also prokarytotic and asexual.
• Archaea do not have different looks structure wise relative to bacteria.
• The difference between them is through the base sequences of rRNA and they are both cell wall and unique in plasma membrane chemistry.
• Archaea live in aquatic environments such as hot, salty, and acidic environments where life may be hard.
• Archaea are likely among the earlier evolved form of life.
• Branched lipids in the plasma membrane of archaea help them thrive in these extreme conditions.
• The halophiles, that are salt lovers surviving in salt or acid filled environments such as in Utah.

Domain Eukarya

• Protists range from unicellular to multicellular forms.
• Some are photosynthesizing; ex. Algae.
• Fungi include molds and mushrooms that decompose organisms to feed themselves.
• Plants are photosynthetic organisms.
• Animals are organisms that need to ingest their food.

Natural Selection

• Natural selection is the possible outcome of adaptation through the environment that chooses the traits passed down the next generations.
• Deer eat leaves, and therefore the dietary habits of the deer affect the characteristics of leaves on a particular land plant, which mutations affect as well.
• A plant species creates the mutation where the leaves of the plant becomes hairy.
• Deer would rather eat smooth leaves, causing plants with hairy leaves to reproduce more.

Biodiversity

• Biodiversity is the total number and relative abundance of species along with the variability that is had between all genes and ecosystems of that species.
• It is estimated that 15 million species exist, and only 2 million have been identified.
• Extinction is the death that species share or any categorization to do with the species.
• Human activity is causing the extinction of 400 species per day.
• For example, fish have disappeared from the reefs of Indonesia through over fishing.
• There was large distinction 65 million years ago.
• The preservation of ecosystems should be the primary issue.