ISCI test 1: modules 1-4

biology

scientific study of life and living organisms

characteristics of life

reproduction, heredity, growth and development, homeostasis, respond to the environment, energy processing, cells

reproduction

all organisms produce new individual organisms either sexually or asexually

heredity

living organisms pass on their traits via genetic information

growth and development

living organisms grow and develop along a specific sequence based on the instructions present in their genes

homeostasis

living organisms maintain the state of steady internal, physical, and chemical conditions

respond to the environment

living organisms respond to stimuli in their respective environment

energy processing (metabolism)

living organisms take in, use and expel energy

cells

living organisms are made of cells

themes that run throughout the study of biology

evolution, structure/function, information flow, energy transformations, interconnections within systems

evolution

natural selection is biology's core unifying theme and can be seen at every level of life

structure/function

the structure of an object provides insight into its function

information flow

information stored in DNA is transmitted and expressed

energy transformations

all biological systems depend on obtaining, converting, and releasing energy and matter

interconnections within systems

all biological systems depend on interactions between components

virus

acellular entities that are composed of genetic material encapsulated in a protein coating

virus characteristics

- they replicate, but need a host
- do not move
- do not produce proteins/energy
- do not grow
- have structure
- can adapt to environmental pressures

bacteria vs. virus

bacteria
- small
- single cell
- reproduce independently
- contain ribosomes and generate ATP
virus
- very small
- acellular
- cannot reproduce independently
- do not contain ribosomes or generate ATP

key characteristics of science

- focuses on the natural world
- aims to explore the natural world
- uses testable ideas
- relies on evidence
- involves the scientific community
- leads to ongoing research
- benefits from scientific behavior

limits of science

- answer questions about morality or ethics
- distinguish or quantify 'beauty' or lack thereof
- tell us what to do with the information it uncovers
- speak to the existence of God or any supernatural event, creature, or pseudoscience
- make people 'accept' science
- answer all questions

science

- an approach to understanding the natural world through inquiry
- a search for information, evidence, explanations, and answers to specific questions
- our knowledge of the natural world and the process through which that knowledge is built

hypothesis

reasoned and informed explanations for a set of phenomena

testing hypotheses can be ____ or ____

experimental (lab or field based) or observational

what to keep in mind when evaluating the validity of scientific claims

- sample size: how many subjects are in each group
- control group: provides more confidence in the difference for variable tested
- reproducibility: other groups should be able to reproduce results

scientific theory

comprehensive explanation of some aspect of nature that is supported by a vasty body of evidence

scientific fact

repeatable observation of the natural world

scientific law

generalization related to the way that some aspects of the natural world behaves under certain conditions

taxonomy

the classification of living things

taxonomic hierarchy

- domain (most common)
- kingdom
- phylum
- class
- order
- family
- genus
- species (least common)

species

- organisms that reproduce asexually
- organisms that can hybridize in nature

systema natura (the system of nature)

- organisms largely grouped based on morphology
- organisms grouped in successively larger groups based on morphological traits

binomial nomenclature

genus
- capitalized
- denotes nearest group of related organisms
species
- lowercase
- denotes organisms capable of interbreeding

living things have evolved into 3 large domains called:

archaea, bacteria, eukaryota

stromatolites

oldest fossils on earth

types of prokaryotes

bacteria and archaea

prokaryote

small, simple, no organelles, single-celled, dna is circular, contain ribosomes and generate atp, dna and other contents enclosed by cell membrane and wall, reproduce independently

true or false? prokaryotes aren't morphologically diverse

false

advantages of prokaryotes

rapid reproduction, rapid mutation, adaption to new environments, more diverse metabolic systems, possess the ability to pass on adaptive genes to other bacteria

metabolic diversity

diversity in the types of compounds that can be used as foods

how are archaea different than bacteria?

- different membrane composition
- rna polymerase is more like eukaryotes
- live in extreme environments

basic unit of life

cell

cells can be grouped into which two categories

prokaryotic and eukaryotic

essential cell and life functions

- program: stores and reads information
- metabolism: gets and uses energy; breaks down, recycles, and removes waste
- container: keeps itself within a container

nucleus

- contains the genetic material of the cell
- directs the activities of the cell
- DNA to RNA to Protein

ribosomes

site where proteins are made

rough endoplasmic reticulum

structure studded with ribosomes that produces and assembles proteins

golgi body/apparatus

where the lipids and proteins made in the ER are modified, sorted, and routed

vesicle

small membrane bound sacs for transport, storage, and intracellular digestion

chloroplasts are found in

all plant species and some protists

mitochondria are found in

all eukaryotic organisms

all cells are surrounded by a

plasma membrane

plasma membrane

lipid bilayer that has two layers of phospholipids and integrated proteins

every membrane is

selectively permeable

transport across membranes can be

passive or active

passive transport

- requires no energy
- substances move along a concentration gradient from high to low
- three types: diffusion, osmosis, and facilitated diffusion

active transport

- requires energy
- substances move against a concentration gradient from low to high
- usually driven by a protein that sits within the membrane

diffusion plays a very important role in

moving substances into and out of cells and around inside of cells

plant, fungal, prokaryotic, and some protist cells have a rigid

cell wall

vesicle

small membrane bound sacs for transport, storage, and intracellular digestion

vacuoles

membrane-bounded sacs for transport, storage, and digestion

flagella

propel the cell through their whip-like motion

cilia

microscopic, hair-like structures that extend outward from the surface of many animal cells

cytoskeleton

network of protein fibers that provides mechanical support, anchorage, and reinforcement

modern tenets of the cell theory

1. all organisms are made of (one or more) cells
2. cells are the basic unit of structure and function in living things (ie. the smallest unit of life)
3. all cells come from preexisting cells