ped
ject
cred
vers, vert
bio
100

a treatment for hands and nails

manicure

100

a word thrown into a sentence, such as "Oh!" or "Wow"

interjection

100

believable

credible

100

the date on which an event is remembered each year

anniversary

100

the study of living things

biology

200

to skillfully operate by hand

manipulate

200

a machine that throws images onto a wall

projector

200

not believable

incredible

200

to turn or flip in the opposite direction

invert

200

a book written about someone's life written by someone else

biography

300

a handbook, a book of directions

manual

300

to throw something out because it can't be used

reject

300

a set of religious beliefs

creed

300

to change your beliefs or way of thinking

convert

300

the zone of earth where there is life

biosphere

400

a person who is in charge of someone else

manager

400

an object thrown into the air with force

projectile

400

to believe someone will do something or that they have already done it

credit

400

a person who turns his attention inward toward himself

introvert

400

when two different organisms live together and depend on each other 

symbiosis

500

handcuffs

manacles

500

to throw stuff overboard to lighten the load (from a sinking boat or an airplane)

jettison

500

a person who believes that he will be paid back the money that he has loaned

creditor

500

to put money into different investments or to make sure there is a bunch of different types of something

diversify

500

the study of the nervous system of living things

neurobiology