Biology - Midterm Exam

organic substance

made of Carbon, used in living things; carbohydrates, proteins, nucleic acids, lipids

carrying capacity

The maximum population size that an environment can sustainably support, taking into account available resources and limiting factors.

Flashcard: Exponential Growth

Rapid increase in population size where individuals reproduce at a constant rate, leading to a steep upward curve on a graph.

logistic growth

Logistic growth refers to a type of population growth where the population initially grows exponentially but eventually levels off due to limiting factors. It is represented by an S-shaped curve and occurs when resources become limited, leading to a decrease in the growth rate. This type of growth is commonly observed in natural populations.

population density

Population density refers to the measurement of the number of individuals living in a specific area, usually expressed as the number of people per square unit of land or volume. It is a key indicator used to understand the concentration of population in a given region and can provide insights into various social, economic, and environmental factors. Population density is calculated by dividing the total population of an area by its land area or volume. It is commonly used in urban planning, resource allocation, and demographic studies.

population

number of individuals of the same species living in a defined area

commensalism

type of symbiotic relationship between two organisms where one organism benefits while the other is neither harmed nor benefited. An example of commensalism is when a bird builds its nest in a tree, using the tree for support and protection, while the tree is unaffected by the presence of the bird's nest.

mutualism

type of symbiotic relationship between two organisms where both benefit from each other. I Examples of mutualism include the relationship between bees and flowers, where bees obtain nectar while pollinating the flowers, and the partnership between certain bacteria and humans, where bacteria aid in digestion while receiving nutrients.

parasitism

type of symbiotic relationship where one organism, called the parasite, benefits at the expense of another organism, called the host. Examples of parasitism include fleas on dogs, ticks on humans, and tapeworms in the intestines of animals.

density dependent factors

Factors that affect the size or growth of a population in relation to its density. These factors include competition for resources, predation, disease, and parasitism. As the population density increases, the impact of these factors becomes more pronounced, leading to a decrease in population growth or even population decline.

density independent factors

Environmental factors that affect a population regardless of its size or density. These factors include natural disasters (such as hurricanes or wildfires), weather events (such as droughts or floods), and other abiotic factors (such as temperature or sunlight). These factors can have a significant impact on population size and distribution, as they can cause widespread mortality or disrupt resource availability.

consumers

organisms that must eat other organisms in order to get energy to maintain life

producers

organisms that can make their own food through sunlight, absorbing inorganic substances from the environment

inorganic substance

do not contain Carbon, necessary to maintain life; water

exotic species

refer to non-native organisms that have been introduced to an ecosystem outside of their natural range. These species are often introduced by human activities, either intentionally or unintentionally. They can have significant impacts on the native species and ecosystems they invade, including competition for resources, predation, and habitat alteration.

invasive species

Non-nativee organisms that have been introduced to an ecosystem and have the potential to cause harm to the environment, economy, or human health. They can outcompete native species, disrupt natural ecosystems, and alter ecological processes. Examples of invasive species include the zebra mussel, Asian carp, and kudzu vine.

predation

a biological interaction where one organism hunts, captures, and feeds on another organism, known as the prey.

water

makes life possible, all organism are mostly made of water (70-95%) and 75% of earth’s surface is submerged in water

• polar molcule

• forms hydrogen bonds with other water molecules and this organized water molecules into higher levels of structural order

surface tension

the tension of the surface film of a liquid caused by the attraction of particles in the surface layer by the bulk of the liquid, which tends to minimize surface area

specific heat

the heat required to raise the temperature of 1 g substance by 1 degree

solvent

does the dissolving, ex. water

cohesion

property of water that describes how water is attracted to itself

solute

is being dissolved, ex. salt

hydrophilic

(likes water) tendency to mix with, dissolve in, or be wetted by water

hydrophobic

(dislikes water) tending to repel or fail to mix with water

adhesion

property of water that describes how water can be attracted to other substances

nucleotide

one of the structural component, or building blocks, or DNA and RNA

phospholipids

a lipid (fat) that contain phosphorus, major part of cell membranes

saturated fat

contain only single bonds

polysaccharide

a large carbohydrate molecule, contains many small sugar molecules that are joined chemically

amino acid

monomer molecules that combine to form proteins

deoxyribonucleic acid

a molecule inside cells that contain the genetic information responsible for the development and function of an organism

(DNA)

unsaturated fat

contain at least one or more double or triple carbon-carbon bond

polymers

any of a class of natural or synthetic substances composed of very large molecule, called macromolecules, that are multiples of simpler chemical units called monomers

• make up many of the materials in living organisms, including, for example, proteins, cellulose, and nucleic acids

carbohydrate

• sugar molecules

• naturally occurring compound

• made up of molecules of C, H, O

• body breaks down carbohydrates into glucose

• glucose is the main source of energy for your body’s cells, tissues, and organs

protein

a molecules made up of amino acids, joined together by peptide bonds

nucleic acid

involves the storage and expression of genomic information

• DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)

monosaccharide

a sugar that is not decomposable into simpler sugars by hydrolysis

• classed as either an aldose or ketose

• contains one or more hydroxyl groups per moleovcule

• called “simple sugar”

lipids

fatty, waxy, or oily compounds that are soluble in organic solvents and insoluble in polar solvents such as water

• includes: fats and oils (triglycerides)

monomer

A molecule that can join together with other molecules to form a polymer. It is the basic building block of a polymer.

steroids

any of a group of lipids (fats) that have a certain chemical structure

• occur naturally in plants and animals, can be made in labs

• ex.) sex hormones, cholesterol, etc.

cholesterol

a waxy, fat-like substance that helps the body make cell membranes, many hormones, and vitamin D

plasma membrane

is selectively permeable

• membrane enclosing the cell

nucleoid

location of circular chromosome in prokaryotic cells

nucleus

the organelle of a eukaryotic cell that contains the genetic material in the form of chromosomes, made up of chromatin

ribosomes

complexes composed of rRNA and protein molecules that function to synthesize proteins

cell wall

rigid outer layer of a plant cell, provides structure and support, made up of peptidoglycan

flagella

hairlike structure that acts primarily as an organelle of locomotion in the cells of many living organisms

cytoskeleton

• microtubules: 25 nm

• intermediate filaments: 8-12 nm, several different proteins

• microfilaments: 7 nm, actin

• provide support, movement, role in development

DNA

deoxyribonucleic acid

chemoautotrophs

energy source: inorganic molecules

vacuole

storage containers

nucleolus

non-membranous structure where ribosomal RNA (rRNA) is synthesized (the two subunits of the ribosome)

eukaryote

• type of cell that contains a nucleus and other membrane-bound organelles

• examples: plant & animal cells

phototroph

organism that can use visible light as a primary energy source for metabolism, process known as photosynthesis

chemotroph

organisms that obtain energy by the oxidation of reduced compounds

pili

protein structures that extend from the bacterial cell envelope

plasmids

extra chromosomal material

chromosomes

• structure found inside the nucleus of a cell

• made up of proteins and DNA organized into genes

• each cell normally contain 23 pairs of chromosomes

golgi apparatus

• modifies and sorts proteins and lipids

• uses vesicles to send these substances to their intended locations

chloroplast

• organelle where photosynthesis takes place (process where energy from sunlight is converted to chemical energy, which is stored in sugar molecules)

• found in plants, but not in animals cells

thylakoid membranes

Found inside the chloroplast, contain chlorophyll where the light-dependent part of photosynthesis occurs

centrosomes

cellular structure involved in the process of cell division

cytoplasm

the contents of the cell, which are bounded by the plasma membrane in a semi-soild solution

vesicles

a small sac formed by a membrane and filled with liquid

• move substances into or out of the cell

bacteria

a large group of single-cell microorganisms, prokaryote

• singular: bacterium

autotroph

an organism that can produce its own food using light, water, carbon dioxide, or other chemicals

• also called: producers

nuclear envelope

double membrane structure, which enclosed the nucleus

• perforated with pores

endoplasmic reticulum

(ROUGH)

• network of membranous sacs and tubes

• outer surface contains ribosomes

• secretory proteins are packaged into transport vesicles and carried to the golgi apparatus

• membrane-bound proteins are synthesized directly into the membrane

(SMOOTH)

• network of membranous sacs and tubes

• outer surface lacks ribosomes

• functions in diverse metabolic processes which vary will cell type

prokaryote

organisms whose cells lack a nucleus and other organelles

• two distinct groups: bacteria and the archaea

mitochondria

Membrane-bound organelle that makes ATP (cell energy) through a process called cellular respiration

central vacuole

Large vacuole found in plant cells that holds extra water and nutrients for the cell

provides ‘turgor pressure’ to help the plant have rigidity

nuclear pore

opening in the nuclear membrane that allows RNA and other molecules to pass in and out of the nucleus

lysosomes

organelle in eukaryotic cells that is used to break down old organelles or other waste products

thylakoid membrane

membrane that surround the thylakoid in a chloroplast

symbiotic

close associations formed between pairs of species. They come in a variety of forms, such as parasitism (where one species benefits and the other is harmed) and commensalism (where one species benefits and the other is neither harmed nor helped).

archaea

means ancient, type of protist cell that usually lives in extreme environments

heterotroph

organism must eat or ingest something to gain energy

lipid

group of organic molecules that are all hydrophobic. Their main function is to provide long term energy storage, protect and cushion

intergral protein

A protein that is embedded in the cell membrane. It is permanently attached to the membrane. and is visible from both sides (it sticks all the way through the membrane)

phagocytosis

cell eating

diffusion

movement of a solute from an area of greater concentration to an area of lesser concentration

osmosis

movement of a solvent from an area of greater concentration to an area of lesser concentration

hypertonic

higher solute concentration causes cell to shrink

isotonic

equal solute concentration, causes no net change in the cell

hypotonic

lower solute concentration, causes the cell to swell

passive transport

• movement of material from an area of greater to lesser concentration

• no energy required

• simple and facilitated diffusion

ion channels

pores in the cellular membrane that allow the passage of ions across the impermeant lipid cell membrane

chemical gradient

the concentrations of molecule on two sides of a membrane are unequal

exocytosis

fusion of secretory vesicles with the plasma membrane

pinocytosis

cell drinking

• an active, energy consuming process where extracellular fluid and solutes are taken up into a cell via small vesicles

active transport

• movement of material against a concentration gradient

• requires energy (usually ATP)

• mediated by a carrier protein

• ex.) sodium-potassium pump

facilitated diffusion

molecules diffuse across the plasma membrane with assistance from membrane proteins, such as channels or carriers

transport protein

membrane proteins that aid in the facilitated diffusion or active transport of ions across the hydrophobic lipid bilayer

channel proteins

a protein that allows the transport of a specific substance across the cell membrane

carrier proteins

• type of transport protein

• acts like a pore in the membrane that lets water molecules or small ions through quickly

endocytosis

the ingestion of large particles (such as bacteria) and the uptake of fluids or macromolecules in small vesicles

phospholipid bilayer

a two-layered arrangement of phosphate and lipid molecules that form a cell membrane

• hydrophobic lipid ends facing inwards and the hydrophilic phosphate ends facing outwarda

metabolism

the totality of an organism’s chemical processes