Y
yellow - ad. having the color like that of gold or the sun
yes - ad. used to express agreement or to permit
yesterday - n. the day before today
yet - ad. at some time before now （"Have they arrived yet?"）; now; at this time （"I cannot tell you about it yet."）; conj. however （"The sun was shining, yet it was cold."）
you - pro. the person or persons being spoken to
young - ad. in the early years of life; not old
Z
zoo - n. a place where animals are kept for the public to look at and study
Common Prefixes
dis - not （dishonest, disobey）
pro - for, supporting （pro-labor, pro-government）
re - to do again （reorganize, reunite）
self - used to show that the person or group acting is the one affected by the action, or to show that the action is done only by its own effort or power （self-declared, self-appointed）
un - not （unusual, unhappy）
Common Expressions
carry out - to do; to put into effect （"Please carry out the plan."）
pass a bill - approve （"Congress is expected to pass a bill to cut taxes."）
take steps - to start to do something （"The government will take steps to halt inflation."）
Words Used in VOA Special English Science Programs
atom - a very small part of all things; the smallest part of an element that can join with parts of other elements
bacteria - living things that are one cell and can be seen only through a microscope; some cause disease
cell - a small mass of living material that is part of all plants and animals
chromosome - a line of genes; most human cells contain 46 chromosomes
compound - a substance containing two or more elements
dense - close together; thick
electron - a small part of an atom that has an electrical force
element - one of more than 100 substances known to science that cannot be separated into other substances
enzyme - a special kind of protein; it produces changes in other substances without being changed itself
fetus - unborn young
fission - a splitting; in atomic fission, the nucleus of an atom is split to produce nuclear energy
fusion - a joining together; in atomic fusion, atomic particles are joined together to produce nuclear energy
genes - parts of cells that control the growth and development of living things; genes from the mother and father are passed to the child; genes contain nucleic acid
genetic engineering - the science of changing the genes of a living organism
gravity - the force that pulls things toward the center of the earth
image - a reproduction of the appearance of a person or thing
laser - an instrument that makes a thin, powerful light
magnet - a piece of iron or other material that has a pulling force; this pulling force is called magnetism
molecule - the smallest amount of a chemical substance that can exist
nerve - a thin piece of tissue that sends information through the body to and from the brain
nucleus - the center part of an atom or cell
nucleic acid - a molecule that holds the genetic information necessary for life; there are two kinds of nucleic acid: DNA （deoxyribonucleic acid） and RNA （ribonucleic acid）
nutrient - a food or substance that makes plants, humans or animals grow
organ - a part of the body that has a special purpose, such as the heart or brain
organism - a living thing, often so small it can be seen only through a microscope
particle - a very small piece of matter
proteins - substances responsible for the growth of tissue and for fixing damaged tissue
robot - a machine that moves and performs tasks
tissue - living material; a group of cells that are similar in appearance and do the same thing
virus - a kind of organism that causes disease
x-rays - a kind of radiation that can pass through most solid materials, often used in medicine
Organs of the Body
heart - pumps blood through the body
intestines - tubes through which food passes after it is broken down in the stomach; part of the intestines also remove solid wastes from the body
kidney - cleans liquid wastes from the body
liver - makes some proteins and enzymes; removes poisons from the blood
lung - takes in and expels air from the body
prostate - a part of the male reproductive system
stomach - breaks down food for the body to use
uterus - a part of the female reproductive system where a fetus develops
yellow - ad. having the color like that of gold or the sun
yes - ad. used to express agreement or to permit
yesterday - n. the day before today
yet - ad. at some time before now （"Have they arrived yet?"）; now; at this time （"I cannot tell you about it yet."）; conj. however （"The sun was shining, yet it was cold."）
you - pro. the person or persons being spoken to
young - ad. in the early years of life; not old
Z
zoo - n. a place where animals are kept for the public to look at and study
Common Prefixes
dis - not （dishonest, disobey）
pro - for, supporting （pro-labor, pro-government）
re - to do again （reorganize, reunite）
self - used to show that the person or group acting is the one affected by the action, or to show that the action is done only by its own effort or power （self-declared, self-appointed）
un - not （unusual, unhappy）
Common Expressions
carry out - to do; to put into effect （"Please carry out the plan."）
pass a bill - approve （"Congress is expected to pass a bill to cut taxes."）
take steps - to start to do something （"The government will take steps to halt inflation."）
Words Used in VOA Special English Science Programs
atom - a very small part of all things; the smallest part of an element that can join with parts of other elements
bacteria - living things that are one cell and can be seen only through a microscope; some cause disease
cell - a small mass of living material that is part of all plants and animals
chromosome - a line of genes; most human cells contain 46 chromosomes
compound - a substance containing two or more elements
dense - close together; thick
electron - a small part of an atom that has an electrical force
element - one of more than 100 substances known to science that cannot be separated into other substances
enzyme - a special kind of protein; it produces changes in other substances without being changed itself
fetus - unborn young
fission - a splitting; in atomic fission, the nucleus of an atom is split to produce nuclear energy
fusion - a joining together; in atomic fusion, atomic particles are joined together to produce nuclear energy
genes - parts of cells that control the growth and development of living things; genes from the mother and father are passed to the child; genes contain nucleic acid
genetic engineering - the science of changing the genes of a living organism
gravity - the force that pulls things toward the center of the earth
image - a reproduction of the appearance of a person or thing
laser - an instrument that makes a thin, powerful light
magnet - a piece of iron or other material that has a pulling force; this pulling force is called magnetism
molecule - the smallest amount of a chemical substance that can exist
nerve - a thin piece of tissue that sends information through the body to and from the brain
nucleus - the center part of an atom or cell
nucleic acid - a molecule that holds the genetic information necessary for life; there are two kinds of nucleic acid: DNA （deoxyribonucleic acid） and RNA （ribonucleic acid）
nutrient - a food or substance that makes plants, humans or animals grow
organ - a part of the body that has a special purpose, such as the heart or brain
organism - a living thing, often so small it can be seen only through a microscope
particle - a very small piece of matter
proteins - substances responsible for the growth of tissue and for fixing damaged tissue
robot - a machine that moves and performs tasks
tissue - living material; a group of cells that are similar in appearance and do the same thing
virus - a kind of organism that causes disease
x-rays - a kind of radiation that can pass through most solid materials, often used in medicine
Organs of the Body
heart - pumps blood through the body
intestines - tubes through which food passes after it is broken down in the stomach; part of the intestines also remove solid wastes from the body
kidney - cleans liquid wastes from the body
liver - makes some proteins and enzymes; removes poisons from the blood
lung - takes in and expels air from the body
prostate - a part of the male reproductive system
stomach - breaks down food for the body to use
uterus - a part of the female reproductive system where a fetus develops