Biology, Unit 1 Flashcards
CELL
The smallest unit that can perform all life processes; covered by a membrane and have DNA and cytoplasm
first person to describe cell
Hooke
Cell theory (part 1)
All organisms are mode of one or more cells
Cell theory (part 2)
The cell is the basic unit of all living things
Cell theory (part 3)
All cells come from living cells
three parts of cells
Cell membrane/cytoplasm; organelles; DNA
cell membrane
A (protective) phospholipid layer that covers a cell’s surface; acts as a barrier between the inside of a cell and the cell’s enviornment
cytoplasm
Fluid inside the cell
organelles
One of the small bodies in a cell’s cytoplasm that are specialized to perform a specific task
DNA
Dioxyribonucleic acid; molecule present in all living cells; the genetic material that carries inherited characteristics; information needed to make new cells and new organisms
types of eukaryotic cells
plant; animal
cell wall
A stiff structure that supports the cell and membrane
ribosome
Organelle that makes proteins (site of protein synthesis); composed of RNA and proteins
nucleus
Contains the cell’s genetic materials
endoplasmic reticulum
A system of membranes with many folds in which proteins, lipids, and other materials are made
mitochondrion
The main power source for the cell
chloroplasts
organelles in which photosynthesis takes place
cytoskeleton
web of proteins inside the cell
vesicle
a small sac that surrounds material to be moved
Golgi complex
packages and distributes proteins
lysosomes
digestive proteins
vacuoles
plant cell’s stores of water and other liquids
cell cycle
birth; growth; division
chromosomes
where DNA is stored; in eukaryotic cells: one of the structures in the nucleus that are made up of 1) DNA and 2) protein; in prokaryotic cells: the main ring of DNA
How do prokaryotic cells divide?
- chromosomes condense from strands into rod structures; 2. membrane dissolves, chromitads align at equator; 3. chromitads separate and move to opposite sides of the cell; 4. cells split/pinch in two
three steps of eukaryotic division
interphase; mitoses; cytokinesis
interphase
duplication of the chromosomes
MITOSIS
the division of eukaryotic cells
cytokinesis
the division of cytoplasm
Why does a cell make a copy of its DNA before it divides?
the other cell must have a copy
Why is cell division in eukaryotic cells more complex than in prokaryotic cells?
eukaryotic cells have a nucleus, but prokaryotic cells do not
GENES
one set of instructions for an inherited trait
four bases found in DNA nucleotides
adenine, thymine, guanine, cytosine
three parts of a nucleotide
phosphate, sugar, base
How are the four kinds of DNA nucleotides different from each other
they each have different bases
What are the sides of the DNA “ladder” made of?
sugar and phosphates
In what form is the DNA in the nucleus?
chromatin / loose
What is chromatin made of?
DNA, proteins
Where is DNA found in a eukaryotic cell?
nucleus/chromosome
amino acid
chemical units that are chained together to form proteins; there are 3 bases that code for each amino acid; there are 20 amino acids
RNA
ribonucleic acid - a molecule present in all living cells and that plays a role in protein production
How does the shape of RNA and DNA differ?
RNA is a straight, single strand that is not a helix while DNA is a double-stranded helix
mutation
A change in the nucleotide-base sequence of a gene or DNA molecule
genetic engineering
when scientists manipulate individual genes within organisms
DNA fingerprinting
methods for identifying the unique patterns in an individual’s DNA
heredity
the passing on of genetic traits from parent to offspring
Gregor Mendel
born in 1822 and grew up on a farm, learning in a monastery; discovered principles of trait inheritance
dominant trait
a trait observed in the first generation where parents that have different traits are bred
recessive trait
a trait that reappears in the second generation after disappearing in the first generation when parents with different traits are bred
alleles
one of the alternative forms of a gene that governs a characteristic such as hair color
phenotype
an organism’s appearance or other detectable characteristic
genotype
the entire genetic makeup of an organism; also the combination of genes for one or more traits
Why do some genotypes have the same phenotype?
The dominant gene in the genotype is what gets expressed in the phenotype, even though two genotypes might differ due to recessive gene
Give an example of a single trait that is affected by more than one gene.
skin color
What affects traits other than genes?
environment
two types of reproduction
sexual; asexual
sexual reproduction
reproduction in which the sex cells from 2 parents unite to produce offspring that share traits from both parents
asexual reproduction
reproduction that does not involve the union of sex cells and in which one parent produces a genetically identical offspring
homologous chromosomes
chromosomes that have the same sequence of genes and the same structure
sex chromosomes
one of the pair of chromosomes that determines the sex of an individual
MEIOSIS
a process in cell division during which the number of chromosomes decreases to half the original number by two divisions in the nucleus, which results in the production of sex cells
sex-linked disorder
a disorder caused by damage on an X chromosome (males are more prone since they only have one X chromosome)
2 ways seedless vascular plants can reproduce
-Asexual -Sexual
2 stages of seedless non-vascular plants life cycle
-Sporophyte -Gametophyte
Fossil fuels
Fuel from living things decaying over time in the ground
Where does coal come from
Seedless vascular plants
How do seedless Vascular plants help make soil?
They break down rock
Non-vascular plants are usually very small. How does their structure limit their size
They don’t have vascular tissue to transpose nutrients
Rhizome (define)
A horizontal, underground stem that produces new leaves, shoots, and roots.
Why are seedless vascular plants larger than seedless non-vascular plants?
They have vascular tissue
ecology
The study of the interactions of living organisms with one another and with their environment.
HABITAT
place where an organism or a community of organisms lives.
fungi
a kingdom made up of non-green, eukaryotic organisms that have no means of movement, reproduce by using spores, and get food by breaking down substances in their surroundings and absorbing the nutrients
spores
a reproductive cell or multicellular structure that is resistant to stressful environmental conditions and that can develop into an adult without fusing with another cell
Yeast
single-celled most of its life, eukaryotic, reproduce asexually by budding or binary fission, produce ascospores.
CLASSIFICATION
the division of organisms into groups, or classes, based upon specific characteristics
What three questions does classification help scientists answer?
- How many known species are there? 2. What are the defining characteristics of each species? 3. What are the relationships between these species?
Carolus Linnaeus
a Swedish scents who contributed classification and taxonomy to science
TAXONOMY
the science of describing, classifying, and naming organisms
branching diagram
A branching diagram lists characteristics of a group of animals and shows similarities and differences
on a branching diagram, where would you see the characteristics that evolved most recently
at the top
list the 8 levels of classification
domain, kingdom, phylum, class, order, family, genus, species
Which level contains organisms that are more closely related: a phylum or class?
class
DICHOTOMOUS KEY
An aid that is used to identify organisms and that consists of the answers to a series of questions
Why couldn’t one single dichotomous key be used for all the organisms on Earth?
sometimes there are things that do not fit into existing category’s
Domains
Classifying organisms into groups by cell types
what are the three domains?
- Archaea 2. Bacteria 3. Eukaryotic
What three kingdoms are in eukarya?
-Animals -Plants -Fungi -Protists
organisms
A living thing; anything that can carry out life processes
ECOLOGY
The study of the interactions of living organisms with one another and with their environment
Biotic
Describes living factors in the environment
Abiotic
Describes the nonliving part of the environment, including water, rocks, light, and temperature
Individual
A single organism
Population
A group of organisms of the same species that live in a specific geographical environment
Community
All the populations of species that live in the same habitat and interact with each other
ECOSYSTEM
A community of organisms and their abiotic, or non-living, relations
Biosphere
The part of earth where life exists
What two kinds of factors does an organism depend on for survival?
Biotic and abiotic
What is the difference between a community and an ecosystem?
An ecosystem is everything something needs to sustain life but a community is just a group of different organisms
producers
organisms that use sunlight to make food
photosynthesis
The process in which plants and sometimes bacteria use sunlight, carbon dioxide, and water to make food
herbivore
an organism that eats plants
consumers
animals that consume other organisms for food
carnivore
an organism that eats meat
omnivore
an organism that eats both meat and plants
scavenger
an organism that eats dead plants and animals
decomposers
organisms that get energy from breaking down the remains of dead organisms or animal wastes and consuming or absorbing the nutrients
FOOD WEB
A diagram that shows the feeding relationships between organisms in an ecosystem
FOOD CHAIN
the pathway of energy transfer through various stages
energy pyramid
a triangular diagram that shows an ecosystem’s loss of energy
Why are producers important in an ecosystem? (pg 486)
because other organisms rely on them as they are the primary source of energy transfer from the sun to other organisms
Why did a change in the wolf population affect the other organisms in the community? (pg 488)
Less wolves resulted in overgrazing of grass to support the elk and other populations which depended on the grass.
What is an energy pyramid? (pg 487)
The energy pyramid is a diagram that shows an ecosystem’s loss of energy. It is wider at the bottom where more energy is and becomes more narrow toward the top. Less energy is available at higher levels because only energy stored in the tissues of an organism can be transferred to the next level.
water cycle pg 508
The movement of water between the oceans, atmosphere, land, and living things. The parts of the water cycle are called evaporation, condensation, and precipitation.
precipitation pg 508
Rain, hail, snow, and sleet falling as a result of condensation
condensation (pg 508)
the change from water vapor to liquid
evaporation (pg 508)
the change from water to water vapor
groundwater (pg 508)
precipitation (water) that seeps into the ground and is stored in spaces between or within rocks; it slowly flows back into the soil, streams, rivers, and oceans
runoff (pg 508)
precipitation (water) that did not go into the ground but flows into streams, rivers, and lakes
transpiration (pg 508)
evaporation of water from leaves and plants
carbon cycle (pg 508)
the exchange of carbon between the environment and living things
explain the role of photosynthesis in the carbon cycle pg 509
photosynthesis is the basis of the carbon cycle and is the process by which plants use carbon dioxide from air to make sugars
respiration (pg 509)
when animals and humans use oxygen to break down sugar molecules to release energy and release carbon dioxide and water as byproducts
decomposition (pg 510)
the break down of substances into simpler molecular substances; in this process carbon dioxide and water are returned to the earth
In the water cycle, what makes water evaporate? (pg 508)
heat from the sun
combustion (pg 510)
the process of burning a substance, such as wood or fossil fuels; releases carbon dioxide into the atmosphere
carbon dioxide in the air is used for….. (pg 509)
photosynthesis
nitrogen cycle (pg 510)
the process in which nitrogen moves between the environment and living things
nitrogen fixation (pg 510)
the process by which bacteria and roots in the soil are able to change nitrogen gas into forms (nutrients) that plants can use
what process releases nitrogen into the soil
decomposition
what is a limiting factor (pg 490)
a resource so scarce it limits the size of a population
carrying capacity (pg 490)
the largest population that and environment can support at any given time
four main ways that individuals and populations affect one another in an ecosystem (pg 490)
g
four resources that all plants compete for (pg 491)
food, shelter, water, space
prey (pg 492)
an organism that is killed and eaten by another
predator (pg 492)
an organism that eats all or part of another organism
name 4 ways prey protect themselves (pg 492-493)
speed/running, venom, camouflage, staying in groups, warning coloration
symbiosis (pg 494)
a relationship in which two different organisms live in close association with each other
mutualism (pg 494)
a relationship between two species in which both species benefit
commensalism (pg 494)
a relationship between two organisms in which one organism benefits and the other is unaffected
parasitism (pg 495)
a relationship in which the parasite is benefitted and the host is harmed
coevolution (pg 495-496)
the evolution of two species that id due to mutual influences
abiotic factors
nonliving factors affecting organisms in an environment
succession
the replacement of one type of community by another at a single place over a period of time
secondary succession
when a small community starts to grow where a previous community was cleared (regrowth after forest fire example)
climax species
well adapted and mature species that may dominate a community
biodiversity
the variety of species present in an area
biome
a large region characterized by a specific type climate and certain types of organisms - a region with similar biotic and abiotic factors
coniferous forests
forests composed of conifer trees (cone bearing seed plants)
temperate grasslands
a biome with few trees and primarily composed of grasses and flowering plants
savanna
a grassland with occasional trees and found in tropical and subtropical areas
deserts
a biome with little plant life or rain and extreme temperatures
polar tundra
a climate in which the soil is frozen, little plant life and no trees
alpine tundra
a tundra that’s elevated above the tree line and has plenty of sun and precipitation
plankton
the mass of mostly microscopic organisms that float freely in freshwater and marine environments
ocean neritic zone
water starts getting deeper; lots of sun; corals, sea turtles, fishes, dolphins
oceanic zone
the zone that contains the deep water of the open ocean, plankton on surfaces, fishes, whales, sharks
benthic zone
the ocean floor; little sunlight or warmth; bacteria get energy from thermal vents; fishes, crabs, bacteria, thermal vents
Sargasso Sea
sea of floating algae in the middle of the atlantic ocean
polar ice
icy water rich in nutrients near the poles
estuary
an area where fresh water from rovers mixes with salt water from the ocean
coral reef
reef made of the skeletons of many corals
intertidal zone
where ocean meets land, exposed to air part of the day; seagrasses, periwinkle snails, and herons
Nutrient
a substance in food that provides energy or helps form body tissues and that is necessary for life and growth
What are some common charachteristics of fungi
How do fungi usually reproduce?
asexually
Name three ways humans use sac fungi.
yeast for bread/alcohol; antibiotics/vitamins; food
Define club fungi and give an example.
umbrella shaped mushrooms like you find at the grocery store
Define imperfect fungi and give an example.
species that do not fit into other groups fo fungi example: Athletes foot
Define lichen.
a mass of fungal and algal cells that grow together in a symbiotic relationship
Name two diseases that can be caused by an imperfect fungus.
athlete’s foot; afflatoxica
Define decomposers.
an organism that gets energy by breaking down the remains of dead organisms or animal wastes and consuming or absorbing the nutrients
mycorrhiza
the mass of fungal filaments or hyphae that form the body of a fungus
Define spores.
a reproductive cell or multicellular structure that is resistant to stressful environmental conditions and that can develop into an adult without fusing with another cell
What three ways can fungi get food?
as consumers (squirt digestive juices into food source); decomposers (eat on dead plant or animal matter); parasites
What are three ways fungi use for asexual reproduction?
hyphae break apart and new piece becomes fungus; spores, budding
Define mold.
a fungus that looks like wool or cotton
Define sporangia.
parts of hyphae that grow into the air and form round spore cases
What two kinds of organisms make up a lichen?
fungi and algae
How do lichens make soil?
They break up rock.
How does a mycorrhiza help both the plant and the fungus?
The plant provides nutrients and the fungus helps get rid of disease.
How are hyphae and mycelium related?
hyphae make up mycellium
What part of a club fungus grows above ground? What part below?
above: spore producing; below: mycelium
Which group of fungi forms basidia during sexual reproduction?
club fungi
What are some common characteristics of fungi?
- Made of eukaryotic cells 2. Rigid cell walls 3. No chlorophyll 4. Heterotrophs
What are 3 common fungi?
- Mold 2. Club 3. Sac
What are two ways that fungi differ from plants?
They don’t make chlorophyll and they have rigid cell walls
Hypha
A non reproductive filament of a fungus
Mycelium
The mass of fungal filaments, or hyphae
Heterotrophs
An organism that gets food by eating other organisms
How do sac fungi usually reproduce?
