Characteristics of Life Notes Honors Bio Unit 1

What is Biology?

The Study of life or living things (Bio=life/living things, ology=study of)

What are the characteristics of living things?

1) Are made of cells and organized
2) Reproduce
3) Grow and Develop"
4) Maintain a stable internal environment (Homeostasis)
5) Change over time
6) Are based on universal genetic code
7) Obtain and use materials and energy
8) Respond to their environment.

What is growth and development mean?

Growth means to increase in size, while development describes the changes that occur as an organism grows.

What is Evolution?

Change over time.

What is the universal genetic code called?

DNA

What are Producers and Consumers?

Producers make their own food while Consumers eat other living things.

What is an Organism?

An individual living thing.

What is a Population?

A group of organisms.

What is a Community?

Populations that live together.

What is an Ecosystem?

A community and its surroundings.

What is a Biome?

A ecosystem and its surroundings.

What is a biosphere?

It contains all the ecosystems (the earth).

How are living things named?

Linnaeus gave 2 word names to living things with the first word being the Genus and capitalized, while the second is the species and is not capitalized. Both words are underlined.

What is Linnaeus’s system of naming things called?

Binomial nomenclature

What are the 3 domains used to classify organisms?

Archaea, Bacteria, Eukarya

Do scientific names change in different languages?

No scientific names are universal regardless of the language spoken by the scientist.

What is a Hierarchy?

All living things are classified in a hierarchy, each category is based on the characteristics shared by all the organisms in that category.

What are Prokaryotes?

The Earth’s oldest organisms and the most abundant ones. Are also the most metabolically diverse of all living organisms. (EX bacteria)

How are Archaebacteria and Eubacteria different from each other?

Eubacteria have cell walls made out of peptidoglycan; archaeabacteria don’t. The plasma membranes of archaebacteria contain lipids which is not found in any other being.

What 2 groups evolved from the ancestral prokaryote?

Archaebacteria and Eubacteria both evolved as 2 structurally and metabolically different groups. So different that they are placed in separate kingdoms.

What are Eukaryotes?

Eukaryotes contain a membrane bound nucleus, internal membranes, and organelles such as mitochondria and chloroplasts. All eukaryotes have mitochondria and some have chloroplasts.

What is the thoery of endosymbiosis?

The theory of endosymbiosis proposes that mitochondria and chloroplasts are the descendants of symbiotic eubacteria that entered large cells and stayed there forming a mutualistic relationship.

What is a characteristic that distinguished eukaryotes from prokaryotes?

The division of the nucleus by mitosis instead of binary fission.

What limits do Unicellular organisms have?

They have limits on their size because as the cell grows, it reaches a point where there is too little surface area to meet the cell’s volume.

What are multicellular organisms made of?

Made of many cells that are permanently associated with each other, each with a special function.

What is the advantage of multicellularity?

It allows the cells to become specialized.

What only occurs in eukaryotes?

True multicellularity only occurs in eukaryotes.

What were multicellular organisms like before cell specailization?

Unicellular organisms first grouped together in colonies, without cell specialization. Later, the colonies evolved into true multicellular organisms.

How are cells grouped in multicellular organisms?

Cells grouped into tissues., Tissues into organs, Organs into organ systems, and systems into organism.

What is asexual reproduction?

Produces many identical offspring in a short time when in a stable environment.

What are the advantages of asexual reproduction?

It is advantageous as no energy is spent finding a mate.

What are the advantages of sexual reproduction?

It provides a way to shuffle the genetic material and to increase the genetic variability in the offspring creating DIVERSITY.

What is genetic diversity?

It is the raw material of evolution.

What did sexual reproduction first evolve as?

It was first evolved as a way to repair damaged DNA strands.

How do the oldest Eukaryotes reproduce?

They reproduced asexually.

What are some of the Eukaryotes life cycles?

Many protists are haploids. Animals and most plants are diploids, and produce haploid gametes.

What is a protist?

A single celled organism, any eukaryotic organism that isn’t a plant, animal, or a fungus.

What does haploid mean?

It describes a cell or organism that only has one completed set of chromosomes.

What does diploid mean?

refers to cells or organisms that have two complete sets of chromosomes, one inherited from each parent.

What are haploid gametes?

They are reproductive sex cells such as sperm and eggs, they contain a single set of chromosomes meaning they have half of the chromosomes found in the bodies typical diploid cells.

What are the characteristics of archaebacteria?

They are all unicellular prokaryotes. Their cell walls lack peptinoglycan. Their plasma membranes contain lipids taht are not found in other living beings. Can either be autotrophic or heterotrophic. Might be ancestors if eukaryotic cells.

What are the three groups of archaebacteria?

Halophiles, thermophiles, and acidophiles. They all live in extreme environments.

What is peptidoglycan?

It is a polysaccharide-peptide polymer which forms the rigid cell wall in most bacteria. It provides structural support and prevents osmotic lysis.

What is osmotic lysis?

The process where a cell bursts open due to excessive water entering the cell, tusi caused the membrane to rupture.

What are halophiles?

It is a extremophile that lives in high salt concentrations.

What is a thermophile?

A extremophile taht thrives at relatively high temperatures.

What is a acidophile?

Organisms that thrive under highly acidic conditions.

What is a extremophile?

A microorganism (usually a archaebacteria) that lives in extreme conditions.

What are the characteristics of eubacteria?

All are unicellular prokaryotes, their cell walls contain peptidolycan, reproduce asexually by binary fission, they can either be autotrophic or heterotrophic. And some of them are photosynthetic. They are extremely diverse groups. And certain types may be the ancestors of mitochondria and chloroplasts.

What is a autotroph?

An organism, that is able to for, nutritional organic substances from inorganic substances (like co2).

What is a heterotroph?

An organism that cannot produce its own food, a consumer.

What are the characteristics of protists?

All of the, are eukaryotic, most of unicellular but some are multicellular. Protists CAN BE autotrophic, heterotrophic, or even both at the same time, they all reproduce asexually, but some can also reproduce sexually.

What are the characteristics of fungi?

They are all eukaryotic, most of them are multicellular, but some are unicellular. The cells walls are made of chitin, NOT CELLULOSE. Fungi have filamentous bodies called hyphae, they are all heterotrophs with external digestion of food, serve as primary decomposers. Reproduce either sexually or asexually.

What does a filamentous body refer too?

It refers to a structure or organism that is elongated and is threadlike, which is often composed of long thin cells that are attached End to end or a bundle of fibrous molecules.

What are fibrous molecules?

Long filamentous molecules that primarily serve structure and protective roles In animals form tissues like tendons skin hair and bones.

What is chitin?

A structural nitrogen - containing polysaccharide thta forms the hard outer covering of arthropods like insects and crustaceans, key component of cell walls of fungi.

What is hyphae?

Each of the branching filaments that make up the mycelium of a fungus.

What is a mycelium?

The vegetative root like network of branches thread like structures called hyphae that forms the main body of fungus.

What is external digestion?

A process where they decrete digestive enzymes into their environment to break down complex organic matter, such as dead plants or animals, into smaller, simpler molecules. These digested nutrients are then absorbed through the organisms mycelium. Allows organisms to obtain nutrients from surroundings instead of ingesting

What are primary decomposers?

Fungi, bacteria, and other microbes that initiate the breakdown of dead organic matter (such as fallen plants and animals) by releasing enzymes to convert complex materials into simpler forms.

What are the characteristics of plants?

All plants are eukaryotic, all plants are multicellular, all plants have cell walls made of cellulose, most plants consist of 2 basic parts called roots and shoots. Most plants are terrestrial and photosynthetic autotrophs. Plants have highly evolved specialized structures for reproduction and survival on land. Plants reproduce sexually, although some can also reproduce asexually.

What is cellulose?

Most abundant compound on earth. A carbohydrates made of glucose units that provides structure to plant cell walls.

What are the characteristics of animals?

All animals are eukaryotes, all are multicellular with cells that lack cell walls. Most reproduce sexually. Are all heterotrophs with internal digestion of food, animals have specialized tissues for movement and reaction to stimuli. Animals inhabit nearly every kind of environment in the biosphere.