UNIT Review Vocab

Cell

the basic unit of structure and function in living things; basic unit of life; so small can only be seen with microscope

Tissues

groups of cells that work together to perform a function

Organs

tissues that work together to perform a function

Organ Systems

organs that work together to perform a function

Microscope

instrument that that uses lenses to magnify small object to make them look larger

Cell theory

scientific theory that states the following:
1. All organism are made of cells.
2.Cells are alive and the basic units of structure and function in all organisms.
3.All cells come from other cells.

DNA

genetic information; deoxyribonucleic acid

Prokatyotes

have prokaryotic cells and are single-celled (unicellular)

Organelle

different parts of a cell; "small organs

Eukaryotes

have eukaryotic cells

Cytoplasm

clear, thick gel like fluid that holds the organelles

Cell Wall

a rigid layer of nonliving material that surrounds plant cells only; is made primarily of cellulose

cell membrane

a cell structure that controls which substances can enter or leave the cell; found in both plant and animal cells

nucleus

the cell's control center; surrounded by the nuclear envelope; contains chromatin, which have all the instruction for cell's functions; contains the nucleolus, where the ribosomes are made

mitochondria

rod-shaped; they change energy in food to energy the cell can use to carry out its functions; cell's "powerhouse

Endoplasmic Reticulum (ER)

forms a maze of passageways in which materials are carried from one part of the cell to the other

Ribosomes

a small grain-like structure in the cytoplasm where proteins are made

Golgi Bodies

receives proteins and other newly formed materials from the ER, packages them, and sends them to other parts of the cell or outside of cell; look like flattened sacks

Chloroplasts

only in plant cells; captures energy from sunlight and uses it to produce food

Vacuoles

storage area; plants usually only have one large one; animal cells may not have one

Lysosome

cell's clean up crew; small and round, contain chemicals that break down certain materials in the cell

Cell division

process in which a parent cell divides to produce daughter cells

cell cycle

phases that a cell goes through from one cell division to the next; life cycle of a eukaryotic cell

Mitosis

division of the nucleus; produces 2 daughter cells that are genetically identical to parent

Meiosis

division of a cell that results in four daughter cells that contain half the amount of DNA than the parent cells; important for creating offspring

Interphase

stage of the cell cycle where the cell grows, make DNA and prepares to divide; has three stages to it: G1, S, and G2

DNA replication

DNA makes an identical copy of itself

Cancer

disease that occurs when the cell cycle is not regulated and cells divide out of control, causing a tumor to form

chromosomes

a doubled rod of condensed chromatin; contains DNA that carries genetic information; has two rods because the cell's DNA has replicated and each rod is an exact copy of the other; each rod is called a chromatid and they are held together by a centromere

Sister chromatids

2 identical copies of a chromosome

Centromere

area of chromosome where sister chromatids are held together

Cytokinesis

cell movement

Gametes

reproductive cells like sperm or eggs; have half the number of chromosomes as parent cell

Sexual reproduction

combining of gametes from two parents

Zygote

Cell that forms when a sperm and egg unite; the first cell of a new organism.

homologous chromosome

pair of chromosomes that have the same size and shape and contain the same genes but different alleles; are similar but NOT identical

Allele

different forms of genes on a chromosome

Haploid

Having one set of chromosomes, as in sperm and egg; n.

Diploid

Having two sets of chromosomes; 2n

Crossing over

exchange of DNA between homologous chromosomes; only happens in prophase I of meiosis