Welcome to high school biology | High school biology | Khan Academy
A1 A2 B1 B2 C1 C2
school
US / sku:l /
•UK / skul /
- adjecitve
- Being to do with schools and education
- noun
- Large group of fish that swim together
- Education of a child
- Building where you learn in classes with a teacher
- A particular belief or idea about something
- verb
- To teach or train someone to know or do something
this
US / ðɪs /
•UK / ðɪs /
- adjecitve
- Used to indicate something already been discussed
- Used to indicate something happening around now
- adverb
- An indication by a physical motion or gesture
- A specific amount of
- determiner
- Person, thing, or idea near you
- pronoun
- Person, thing that has already been discussed
fit
US / fɪt /
•UK / fɪt /
- adjecitve
- Good looking; physically attractive
- Proper or acceptable; morally or socially correct
- noun
- Sudden loss of body control; attack (of crying)
- verb
- To install a machine, equipment etc.
- To adjust or change to the right size or shape
- To be the right size and shape that you want
homework
US / ˈhəumwə:k /
•UK / ˈhomˌwɚk /
- noun
- Work that a student is given to do at home
little
US / 'lɪtl /
•UK / ˈlɪtl /
- adjecitve
- Being short in length of time
- Not great in size, amount, or degree; small
- Being very young or younger than others
- adverb
- By an amount or degree that is not very much
- Not often; rarely
- noun
- A person's name
the
US / ðə /
•UK / ðə /
- article
- Used to refer to something already mentioned
- Used to show there is only one of something
- determiner
- Used to describe all of a family
bad
US / bæd /
•UK / bæd /
- adjecitve
- Not good; wrong
- Lacking in good morals; evil
- No longer fresh; spoiled
one
US / wʌn /
•UK / wʌn /
- pronoun
- You; we; people in general; someone
- The thing or person previously referred to
- adjecitve
- Used to refer to people generally
- Being a strong example of (something mentioned)
- number
- Number 1
other
US / 'ʌðə(r) /
•UK / ˈʌðər /
- adjecitve
- A thing different from that mentioned
- determiner
- (Something) else; not the first (one)
- pronoun
- Being the one and only thing of that category
turn
US / tɜ:n /
•UK / tɚn /
- noun
- Place where changing of direction happens
- Your time or chance to perform a duty
- Your chance to play or do in say a game
- Unexpected change, as in the weather
- verb
- To become (a particular age)
- To become a different quality, color, etc.
- To change the direction of something, e.g. a car
- To move in an opposite direction or position
- To shape metal with a spinning tool
plant
US / plɑ:nt /
•UK / plænt /
- noun
- Factory or a place where things are made
- Living thing with leaves and roots growing in soil
- verb
- To firmly position something (in the ground)
- To put seeds, flowers, trees in the ground
make
US / meɪk /
•UK / mek /
- noun
- Product made by a particular company; brand
- verb
- To arrange or prepare something e.g. dinner
- To get to (a place) on time
- To gain the status of (teacher, lawyer, etc.)
- To create something by putting things together
- To earn a certain amount of money at a job
- To cause or force a person to do something
- To cause something to happen or be formed
universe
US / ˈju:nɪvɜ:s /
•UK / ˈjunəˌvɚs /
- noun
- All of space that contains planets and stars
- Things surrounding a person, affecting their life
how
US / haʊ /
•UK / haʊ /
- adjecitve
- To what degree? in what amount?
- adverb
- (Used to explain the way to do something)
- exclamation
- For what purpose or reason?
- (Used to ask someone or something's condition)
live
US / lɪv /
•UK / liv /
- adjecitve
- Being broadcast as events happen, not recorded
- Carrying electric current; able to give a shock
- Glowing because burning; hot
- Not yet killed (for food)
- adverb
- (Music, drama) as it is performed
- verb
- To be alive
- To experience a particular type of life
- To make your home in a house or town
mutation
US / mju:'teɪʃn /
•UK / mjuˈteʃən /
- noun
- Change that changes genetic structure
sal
US / sæl /
•UK / sæl /
- noun
- A North Indian tree that yields hard, durable timber and dammar resin.
you
US / jʊ /
•UK / ju /
- pronoun
- Person someone is speaking or writing to
- Person or people in general
favourite
US / ˈfeɪvərɪt /
•UK / 'fevərɪt /
- adjecitve
- Best liked or most enjoyed
- noun
- A thing that someone likes best or enjoys most
less
US / les /
•UK / lɛs /
- adjecitve
- Smaller in amount or degree
- adverb
- To a smaller degree
- noun
- A smaller amount
- preposition
- With the subtraction of
another
US / əˈnʌðə(r) /
•UK / əˈnʌðɚ /
- adjecitve
- One more, but not this
- determiner
- One more added
- pronoun
- One more (thing)
complex
US / 'kɒmpleks /
•UK / kəmˈplɛks, ˈkɑmˌplɛks /
- adjecitve
- Not being simple; having many parts or aspects
- noun
- Group of buildings all used for the same purpose
- Psychological issue regarding self-image
preoccupy
US / priˈɒkjupaɪ /
•UK / priˈɑ:kjupaɪ /
- verb
- To cause to be absorbed in thinking about a thing
sometimes
US / ˈsʌmtaɪmz /
•UK / ˈsʌmˌtaɪmz /
- adverb
- Only at certain times; occasionally
particular
US / pəˈtɪkjələ(r) /
•UK / pɚˈtɪkjəlɚ, pəˈtɪk- /
- adjecitve
- One specific (one)
- Having firm ideas about what is desirable
- Being special or more than is typical
think
US / θɪŋk /
•UK / θɪŋk /
- verb
- To have an idea about something without certainty
- To have an idea, opinion or belief about something
far
US / fɑ:(r) /
•UK / fɑr /
- adjecitve
- A long way away
- Being a long way away
- adverb
- To a large degree or extent
trait
US / treɪt /
•UK / tret /
- noun
- A particular characteristic that can produce a particular type of behavior
where
US / hwɛə /
•UK / hwɛr, wɛr /
- conjunction
- At or in the place which
- In whatever place
- pronoun
- Word you use to ask the location of something
ten
US / ten /
•UK / tɛn /
- number
- 10
and
US / ənd /
•UK / ənd, ən,ænd /
- conjunction
- Used to refer to two or more things
- Plus; in addition; on top of that
- Used to introduce an action that follows another
biological
US / ˌbaɪəˈlɒdʒɪkl /
•UK / ˌbaɪəˈlɑdʒɪkəl /
- adjecitve
- Being related to life and living things
intelligence
US / ɪn'telɪdʒəns /
•UK / ɪnˈtɛlədʒəns /
- adjecitve
- Of the spying services; acting in secrecy
- noun
- Collection of secret information about something
- Ability to learn things or to consider situations
lot
US / lɒt /
•UK / lɑt /
- noun
- What happens to a person in life from chance; fate
- A group of people seen together
- Item for sale at an auction
- Small area of land used for a purpose e.g. parking
from
US / frəm /
•UK / frʌm, frɑm,frəm /
- preposition
- Starting at a particular place, time or level
form
US / fɔ:m /
•UK / fɔrm /
- noun
- Sports team or person's current winning record
- Document you complete when making an application
- Visible shape or style; type; kind
- verb
- To organize something such as a club or group
- To develop; to come into a shape or substance
- To make something into a particular shape
out
US / aʊt /
•UK / aʊt /
- adverb
- No longer stylish (e.g. fashion)
- Away from home, business, or the usual place
- In a direction/movement away from inside or center
- noun
- Act when a batter cannot continue playing
- verb
- To tell people a secret
have
US / həv /
•UK / hæv /
- verb
- To drink, smoke, eat or use something
- To experience the effects of something
- To organize an event, or join in an activity
- To own, possess, or hold something
- To cause to happen or produce a particular effect
organize
US / ˈɔ:gənaɪz /
•UK / ˈɔ:rgənaɪz /
- verb
- To arrange and plan things, e.g. a party
sun
US / sʌn /
•UK / sʌn /
- noun
- Light and heat coming from a large star in the sky
- Hot shining star the Earth moves around
- verb
- To lie in the sunshine and enjoy its warmth
know
US / nəʊ /
•UK / noʊ /
- verb
- To be familiar with a person or place, thing
- To feel sure or be convinced about something
- To discover or be aware of something
- To be able to distinguish
- To have knowledge of things
moment
US / 'məʊmənt /
•UK / 'moʊmənt /
- noun
- Very short or brief period of time
- A particular period in time
see
US / si: /
•UK / si /
- verb
- To go on a date with someone
- To predict whether something is, or will be true
- To understand what someone says
- To use your eyes to look at something
- To visit a place often for sightseeing or pleasure
- To visit or meet with someone
- To find out by waiting or looking
- To watch (a game, movie or TV show)
focus
US / 'fəʊkəs /
•UK / ˈfokəs /
- noun
- Main purpose or center of interest or activity
- verb
- To see clearly by adjusting your eyes or a camera
- To keep your attention, concentration on one thing
mirror
US / 'mɪrə(r) /
•UK / ˈmɪrɚ /
- noun
- Thing with glass surface used to look at yourself
- An accurate impression or picture of something
- verb
- To reflect (an image)
- To have similar qualities to something else
with
US / wɪð /
•UK / wɪð, wɪθ /
- preposition
- As an employee of a certain company
- Against something or someone
- By using something as a means
- Due to; because of
- Including
- Possessing as a feature
- Related to
- (Of the manner/attitude by which you do something)
- Used to express that people or things are together
next
US / nekst /
•UK / nɛkst /
- adverb
- The one that follows another in time or order
- At a time or place directly after the present one
- noun
- The one that follows after
- adjecitve
- Immediately after the previous one
- First occurrence after the present one
incredibly
US / ɪnˈkredəbli /
•UK / ɪnˈkrɛdəblɪ /
- adverb
- To a great degree; very; amazingly
maybe
US / ˈmeɪbi /
•UK / ˈmebi /
- adverb
- Possibly but not certainly; perhaps
our
US / 'aʊə(r) /
•UK / aʊr /
- determiner
- Belonging to us
not
US / nɒt /
•UK / nɑt /
- adverb
- Word indicating the negative
- (Used to form the negative of verbs)
themselves
US / ðəmˈselvz /
•UK / ðɛmˈsɛlvz, ðəm- /
- pronoun
- Reflexive form of 'they'
meal
US / mi:l /
•UK / mil /
- noun
- Food for eating at a particular time, e.g. dinner
- Grain that has been ground into a powder
perception
US / pəˈsepʃn /
•UK / pɚˈsɛpʃən /
- noun
- Way in which one sees or understands something
replenish
US / rɪ'plenɪʃ /
•UK / rɪˈplɛnɪʃ /
- verb
- To fill up again
pick
US / pɪk /
•UK / pɪk /
- noun
- Sharp tool used for breaking the ground
- Item selected from a group of choices
- verb
- To take fruit or vegetables from a plant or tree
- To decide on a thing from various choices; select
- To remove (flower, etc.) with your fingers
understand
US / ˌʌndə'stænd /
•UK / ˌʌndɚˈstænd /
- verb
- To know the meaning of language, what someone says
video
US / 'vɪdɪəʊ /
•UK / ˈvɪdiˌo /
- adjecitve
- Of a moving film, with sound
- noun
- Recording capturing action with sound
- verb
- To make a moving film of, with sound
but
US / bət /
•UK / bʌt,bət /
- conjunction
- Used before you say something different, opposite
especially
US / ɪˈspeʃəli /
•UK / ɛˈspɛʃəli, ɪˈspɛʃ- /
- adverb
- More than usual; extremely
good
US / ɡʊd /
•UK / ɡʊd /
- adjecitve
- Proper, appropriate or right
- (Of an amount) enough; plenty
- Excellent; high quality
- Acting well or properly; of moral character
- In a positive or happy emotional state
- noun
- Advantage or benefit
life
US / laɪf /
•UK / laɪf /
- noun
- All the living things e.g. animals, plants, humans
- Period of time things live, from birth to death
now
US / naʊ /
•UK / naʊ /
- adverb
- At the present time or moment
- Right away or in the next possible moment
- Used to refer to something that just happened
- Time between the present and a moment in the past
- conjunction
- Resulting from or because of something
planet
US / 'plænɪt /
•UK / ˈplænɪt /
- noun
- One of the bodies that orbit the sun
child
US / tʃaɪld /
•UK / tʃaɪld /
- noun
- A very young person, between about 2 and 15
surround
US / səˈraʊnd /
•UK / səˈraʊnd /
- other
- To be closely connected to and have an effect on
- verb
- To be all the way around something
- To be closely connected to and have an effect on
- To move closer on all sides of something
somehow
US / ˈsʌmhaʊ /
•UK / ˈsʌmˌhaʊ /
- adverb
- In a way that is not known or certain
actually
US / ˈæktʃuəli /
•UK / ˈæktʃuəli /
- adverb
- Used to add new (often different) information
use
US / ju:s /
•UK / ju:s /
- noun
- Ability to employ something
- Need to enable it to work
- Permission to do something with something
- Act of spending money
- Operation of a machine for its function
- verb
- To have; to eat, drink, consume etc.
- To need to operate or work
- To operate a machine, e.g. a computer
- To treat a person badly
- To do something with, for a task or purpose
always
US / 'ɔ:lweɪz /
•UK / ˈɔlwez,-wɪz,-wiz /
- adverb
- For a very long time
- At all times; in every situation
- For ever
notion
US / ˈnəuʃən /
•UK / ˈnoʃən /
- noun
- Sudden idea or desire to do something
relate
US / rɪ'leɪt /
•UK / rɪˈlet /
- verb
- To demonstrate a logical relationship between
- To understand or sympathize with, e.g. a problem
- To tell a story, or tell about a particular event
will
US / wɪl /
•UK / wɪl /
- noun
- Desire or choice of someone
- Document saying who gets your money when you die
- Strong desire to do something; determination
- Desire to do something; strong wish to do
- other
- Used with verbs to express the future
- verb
- To leave property to someone after your death
- To use mental effort to make something happen
- Am (is, are) likely to do
- To influence someone to do something
- To make something happen by strongly wanting it
tax
US / tæks /
•UK / tæks /
- noun
- Money taken by a government from its people
- verb
- To require a lot of physical or mental effort
- (Government) to take money from a country's people
then
US / ðen /
•UK / ðɛn /
- adverb
- A time that is not now
- Following another thing in time or arrangement
- Following on reasonably from what was just stated
- At that time, not now
bacteria
US / bæk'tɪərɪə /
•UK / bækˈtɪriə /
- noun
- The very small creatures that can cause disease
directly
US / dəˈrektli /
•UK / dɪˈrɛktli, daɪ- /
- adverb
- In a frank and honest way
- Right away; immediately
get
US / ɡet /
•UK / ɡɛt /
- verb
- To become affected by illness or disease
- To begin to feel or understand an emotion or idea
- To send or bring someone or something home, etc.
- To go somewhere to obtain something
- To (cause to) do a particular thing
- To obtain, receive or be given something
- To currently have
- To prepare for use
- To understand something being said or read
hard
US / hɑ:d /
•UK / hɑː(r)d /
- adjecitve
- Difficult to do; difficult to understand
- (Of facts) not able to be misunderstood; clear
- (Of alcohol) strong
- Involving or requiring lots of work, effort, care
- Being full of pain, trouble, and problems
- Strong
- (Of edge) clear; sharp
- Difficult to bend, break or cut; solid
- adverb
- With lots of force, power, or impact
energy
US / 'enədʒɪ /
•UK / ˈɛnədʒi /
- noun
- Physical or mental strength
right
US / raɪt /
•UK / raɪt /
- adjecitve
- Correct or true
- The south side of you looking at the rising sun
- adverb
- Exactly in a place or time
- Being appropriate for a particular event
- In a straight or direct manner
- noun
- Something you are legally or morally allowed to do
- Ideal of what is just and good
- Political view based on conservatism
- verb
- To fix something previously wrong or unjust
- To make upright, as a boat that has turned over
sensory
US / ˈsensəri /
•UK / ˈsɛnsəri /
- adjecitve
- Referring to the physical senses
interesting
US / ˈɪntrəstɪŋ /
•UK / ˈɪntrɪstɪŋ, -tərɪstɪŋ, -təˌrɛstɪŋ /
- adjecitve
- Taking your attention; making you want to know
- verb
- To make someone want to know about something
- To persuade to do, become involved with something
cell
US / sel /
•UK / sɛl /
- noun
- Smallest unit of living things in biology
- Group of people - often from a secret organization
- Prisoner's room in a jail
- Shortened form of 'cellphone'
each
US / i:tʃ /
•UK / itʃ /
- determiner
- Every one of two or more things
- pronoun
- Per one person or thing
emerge
US / ɪ'mɜ:dʒ /
•UK / ɪˈmɚdʒ /
- verb
- To rise or appear out of some background
happen
US / 'hæpən /
•UK / ˈhæpən /
- verb
- To take place or occur
understanding
US / ˌʌndəˈstændɪŋ /
•UK / ˌʌndərˈstændɪŋ /
- adjecitve
- Being sympathetic
- noun
- When you get the meaning correctly; comprehension
- Knowledge about something or someone
- verb
- To know the meaning of language, what someone says
about
US / ə'baʊt /
•UK / əˈbaʊt /
- adverb
- To be ready to; going to
- Nearly; approximately; roughly
- Near; next to; close to
- In every direction; in the area of
- preposition
- Concerning or of (a topic)
even
US / 'i:vn /
•UK / ˈivən /
- adjecitve
- Being equal in influence, power, possibility etc.
- Being divided equally or fairly
- (Of teams/contest) with similar chances of success
- Smooth, level, or regular
- Can be divided by 2; ending in 2, 4, 6, 8, or 0
- At a regular, equally steady manner
- Remaining steady and unchanging
- adverb
- (When this is surprising) as well; too
- (Used to compare two things/stress the difference)
- verb
- To make something level; to flatten
- To make something equal
interconnect
US / ˌɪntəkəˈnekt /
•UK / ˌɪntərkəˈnekt /
- verb
- To join or be joined together (computers/theories)
like
US / laɪk /
•UK / laɪk /
- adjecitve
- Being equal in status or kind to something else
- Similar; the same
- adverb
- For example
- preposition
- Used as a filler; used to ad emphasis
- In a way similar to the way something is done
- Such as; for example
- verb
- To want to
- To find something pleasing; to prefer something
people
US / 'pi:pl /
•UK / ˈpipəl /
- noun
- Persons sharing culture, country, background, etc.
- Men, Women, Children
that
US / ðæt /
•UK / ðæt, ðət /
- adjecitve
- The person or thing being talked about
- Used to identify something both the speakers know
- adverb
- Used to reinforce adjectives and adverbs
- To such a degree
- conjunction
- Used to connect a noun clause
- Used to introduce an adverbial clause
- Used to introduce a noun clause
- determiner
- Used as a noun to refer to something
- pronoun
- Referring an object far away
- Used to refer to the relative pronoun ‘which’
what
US / wɒt /
•UK / hwɑt, hwʌt, wɔt, wʌt,hwət, wət /
- pronoun
- Thing or things that; the same kind as
- Used to emphasize something you are about to say
- adjecitve
- Used to refer to a particular amount, or number
- Used to place emphasis on a particular quality
- adverb
- To a certain degree
- determiner
- Question words used for asking for information
- exclamation
- Used to express excitement, shock, or surprise
- Used to ask people to repeat something they said
worry
US / ˈwʌri /
•UK / ˈwɜ:ri /
- noun
- Something that causes trouble or concern
- verb
- To cause concern or trouble over something
all
US / ɔ:l /
•UK / ɔl /
- adverb
- Completely; totally
- determiner
- Being every one of something
- pronoun
- 100% of something; the complete amount
biology
US / baɪˈɒlədʒi /
•UK / baɪˈɑlədʒi /
- noun
- The study of living things
bit
US / bɪt /
•UK / bɪt /
- noun
- Device put in a horse's mouth to control it
- Small piece of something
- verb
- (E.g. of fish) to take bait and be caught
encourage
US / ɪn'kʌrɪdʒ /
•UK / ɛnˈkɚrɪdʒ, -ˈkʌr- /
- verb
- To increase the chance of something happening
- To make someone more determined or confident
look
US / lʊk /
•UK / lʊk /
- noun
- Person's beauty or physical attractiveness
- Particular style of dress, clothes, or appearance
- The way someone, something appears to be
- Act of searching for or examining something
- verb
- To appear to be; seem
pay
US / peɪ /
•UK / pe /
- noun
- Money you receive from your job, work, etc.
- verb
- To give money for goods or work done
- To give (attention, respect, etc.) to
- To be punished or suffer for something you did
- To make (a visit) to a person or place
solar
US / 'səʊlə(r) /
•UK / ˈsolɚ /
- adjecitve
- Concerning the sun, or its heat
miraculous
US / mɪˈrækjələs /
•UK / mɪˈrækjələs /
- adjecitve
- Wonderful; extraordinary
take
US / teɪk /
•UK / tek /
- noun
- Filming of a single scene for TV or the movies
- verb
- To accept something that is offered
- To use a method of traveling, e.g. a bus or train
- To use a camera to make (a photo)
- To pick up something and go away with it
- To study a subject in school
- To attempt to pass (an exam)
- To require a certain amount of time, money, space
they
US / ðeɪ /
•UK / ðe /
- pronoun
- Two or more people, animals, or things
topic
US / 'tɒpɪk /
•UK / ˈtɑpɪk /
- noun
- Subject or issue people talk or write about
very
US / 'verɪ /
•UK / ˈvɛri /
- adjecitve
- Concerning a large degree or amount
- adverb
- A lot; much; many
- Used to stress or emphasize a noun
ask
US / ɑ:sk /
•UK / æsk /
- verb
- To say to someone that you want something
pause
US / pɔ:z /
•UK / pɔz /
- noun
- A temporary break before continuing
- Function on a device to stop and restart it
- Sign to hold a musical note a bit longer
- verb
- To stop doing for a while before continuing
start
US / stɑ:t /
•UK / stɑrt /
- noun
- First time or place that a thing exists; beginning
- First opportunity to achieve something, e.g. a job
- Sudden action or movement because you are scared
- other
- Beginning of something in place or time
- verb
- To do, be or happen for the first time; begin
- To turn something on
amazing
US / ə'meɪzɪŋ /
•UK / ə'meɪzɪŋ /
- adjecitve
- Surprising in a pleasing way
- verb
- To cause wonder; to surprise completely
basis
US / ˈbeɪsɪs /
•UK / ˈbesɪs /
- noun
- Main ingredient or part of something
- Starting situation, fact, idea to develop from
just
US / dʒʌst /
•UK / dʒʌst /
- adjecitve
- Proper or appropriate; as is deserved
- Doing or being what is right or fair
- Legally correct; having enough evidence
- adverb
- Almost; nearly
- Exactly at the time of
- Exactly (the same as, like)
tens
US / tɛnz /
•UK / tɛnz /
- number
- 10s
wonder
US / 'wʌndə(r) /
•UK / ˈwʌndɚ /
- noun
- Surprise caused by experiencing something amazing
- verb
- To feel curious about something
- To think or consider about something over time
generation
US / ˌdʒenəˈreɪʃn /
•UK / ˌdʒɛnəˈreʃən /
- noun
- Act or process of producing or causing something
- People born and living at about the same time
those
US / ðəʊz /
•UK / ðoz /
- determiner
- The people or things we are talking about
- pronoun
- The objects far from the speaker
system
US / 'sɪstəm /
•UK / ˈsɪstəm /
- adjecitve
- Working in an organized, logical way
- noun
- Set of organized, planned ideas that work together
for
US / fə(r) /
•UK / fɔr,fə /
- preposition
- Used to show the purpose, or need of something
grant
US / ɡrɑ:nt /
•UK / ɡrænt /
- noun
- Money given for education or research
- Person's name
- verb
- To admit an opinion is true but not fully agreeing
- To give or let someone do what they want