Biology Unit 1 & 2

Biology

the scientific study of life

Science

an approach to understanding the natural world that is based on inquiry

What do scientists seek?

natural causes for natural phenomena

What. do. scientists focus solely on?

the study of structures. and processes that an be observed and measured

Data

recorded observations

Hypothesis

a proposed explanation for as et of observations

what makes a hypothesis valid?

it must be tenable and falsifiable

why do scientists rely on?

scientific literature

Peer Review

the process of research being evaluated

Theory

an explanation that is supported by abundant evidence. that generates new testable hypotheses and is broader than a hypothesis

Fact

a piece of information considered to be objectively true based on. all current evidence

Variables

factors that change in an experiment

Controlled Experiment

one. that compares two or more groups that differ only in one. variable that the experiment is designed to test

Control Group

lacks or does not receive the specific factors being tested

Experimental Group

has or recieves the specific factor being tested

what are the properties of life?

order, cells, regulation, growth & development, energy processing, response to environment, reproduction, and evolution

what are the five themes in biology?

evolution, structure/function, information flow, energy transformations, and interconnections

Natural Selection

a mechanism for evolution where individuals with heritable traits best suited to the environment are most likely to survive and reproduce

what two are often related?

structure and function

Genes

the units of inheritance that a transmit information from parent to offspring

what are the four building blocks of DNA?

A, G, C, T

Genome

the entire set of genetic information that an organism inherits

how is life made possible?

the input of energy and transformation of energy from one form to another

how much do organisms outnumber cells by?

10 to 1

Microbial Communities

increase our susceptibility to infectious diseases and contribute to diseases such as asthma, IBS, Crohn’s and autism

when was earth formed?

4.6 billion years ago

when did prokaryotes evolve?

3.5 billion years ago

when was oxygen produced?

2.7 billion years ago

when did eukaryotes evolve?

1.8 billion years ago

when did the first multicellular eukaryotes evolve?

1.2 billion years ago

when was the Cambrian explosion?

540 million years ago

what did the cambrian explosion do?

resulted in the evolution of all major animal body plans

when did plants, fungi, and insects begin to colonize the land?

500 million years ago

when did the mesozoic era end?

65 million years ago

what happened at the end of the mesozoic era?

flowering plants, birds, and mammals, including primates, barn to dominate the land

when did humans originate?

195,000 years ago

what was wrong with young earth?

is was too hard for anyone to survive

what was wrong with the earth 4 billion years ago?

it was still in violent turmoil from water vapor condensing into oceans and volcanic eruptions

what are the four stages of origin of life?

synthesis of small. organic molecules, building. macromolecules, packing molecules into pre-cells, and origins of self-replicating molecules that made inheritance possible

how long were prokaryotes alone on earth?

2 billion years

what is significant about prokaryotes?

they are found wherever there is life and can thrive in extreme environments

what causes half of all human diseases?

prokaryotes

Prokaryotic Cells

lack a membrane enclosed nucleus and organelles, have cell walls exterior to plasma membrane, and use flagella to be motile

what are the three common shapes of prokaryotes

spherical (cocci), rod-shaped (bacilli), and spiral

Biofilms

one or more species of prokaryotes living in a highly organized community attached to a surface

how do prokaryotes reproduce?

binary fission

how to prokaryotes obtain energy?

photosynthesis through organic matter

what do prokaryotes do for the ecosystem?

recycle chemical. elements between biological and physical components and breakdown organic wastes

what is bioremediation?

the use of organisms to remove pollutants from water, air, or soil

Thermophiles

achaea that live in very hot water

Halophiles

archaea that thrive in high salt

Methanogens

archaea that live in oxygen free environments

Pathogens

bacteria that can cause disease

Exotoxins

proteins that bacterial cells secrete into their environments

Endotoxins

chemical components of the outer membrane of certain bacteria

what are the best ways to prevent bacterial disease?

sanitation, antibiotics, and education

Bioweapons

the use of pathogens to case serious harm

what is the greatest threat form endospores?

anthrax

Botulinum

an exotoxin that is the deadliest poison on earth which blocks nerve signals that cause muscle contraction resulting in paralysis of the muscles required to breathe

how did the first eukaryotes evolve?

endosymbiosis

how do parasites acquire nutrients?

a living host

what are protozoans?

protists that live primarily by ingesting food

where do protozoans thrive?

aquatic environments

what do protozoans have the ability to cause?

diseases like malaria and giardia

what are flagellates, amoebas, forams, apicomplexans, and cilates?

protozoans

what are slime molds?

multicellular protists related to amoebas and feed on dead plant material

what is algae

protists whose photosynthesis supports food chains in freshwater and marine ecosystems

what is used to produce biofuels?

algae

what is streptococcus mutans?

bacteria that thrives in the tiny crevices in tooth enamel

what is sucrose used for?

making glue that builds up deposits of plaque

what led to s. mutans taking over the human microbiome?

shift to a high sugar diet

what do truffles represent?

the essential role of fungi to the plant kingdom

whaat are roots surrounded by?

fne webs orr fungal filaments

why is symbiosis

an interaction in which one species live in. or on another species

what do fungal filaments do?

absorb water and inorganic nutrients and pass them to the plant which supplies the fungus with sugars and other organic molecules

what is a plant?

a multicellular eukaryote that carries out photosynthesis and has a set of adaptions for living on land

what are roots?

subterranean organs that anchor the plant in soil and absorb minerals and water from the soil

what is mycorrhizae?

symbiotic associations of fungi and roots which enlarge the root’s functional surface area

what are leaves?

the main photosynthetic organs of plants

what are stomata?

pores that allow the exchange of carbon dioxide and oxygen with the atmosphere

what is the cuticle?

a waxy layer coating the leaves called the cuticle that allows water retention

what is vascular tissue?

a network of tube-shaped cells for the transport of vital materials between roots and shoots that leaves contain

how did algae reproduction adapt to land?

the surrounding water ensures that gametes can disperse and the developing offspring can stay moist

how did plant reproduction adapt to land?

the zygote developed into an embryo while still contained within the female parent which protects it from being dehydrated

when did bryophytes evolve?

470 million years ago

when did ferns evolve?

425 million years ago

when did gymnosperms evolve?

360 million years ago

when did angiosperms evolve?

140 million years ago

what are bryophytes?

mosses that sprawl as low mats over acres of land

whaat two adaptations gave moss the ability to move onto land?

waxy cuticles and retention of developing embryos within the female plant

what do gametophytes produce?

gametes that unite and develop into new sporophytes

what do sporophytes release?

spores that develop into gametophytes

what are ferns?

seedless vascular plants

what are gymnosperms

seeded plants

what adaptations gave gymnosperms the ability to survive on land?

reduction of the gametophyte, pollen, and seeds

what are angiosperms?

flowering plants

what is fruit?

a ripened ovary that helps protect the seed and is a major food source for animals

what is fungi?

eukaryotes that recycle vital chemical elements back to the environment in forms other organisms can assimilate

how do fungi acquire nutrients?

absorption

what is hyphae?

threadlike filaments that fungi are constructed of