biology pt 2

Cell

the smallest basic unit of life

Cell membrane (Part of Cell)

A soft outer wall that holds the cell together and lets good things in or out.

cell theory

a theory that all living things are made up of one or more cells; that cells are the basic unit of life; and that all cells come from pre-existing cells.

organelle

a cell structure that performs a specific function for the cell.

prokaryote

a cell that does not contain a nucleus or other membrane-bound organelles.

eukaryote

a cell that contains a nucleus and other organelles; each surrounded by a thin membrane.

asexual reproduction

the process of producing offspring from only one parent; the production of offspring that are genetically identical to the parent.

sexual reproduction

the process of producing offspring by the fusion of two gametes; the production of offspring that have genetic information from each parent.

concentration

the amount of a substance (solute) present in a given volume of solution.

osmosis

the movement of a fluid (usually water) across a membrane toward an area of high solute concentration.

diffusion

a transport mechanism for moving chemicals into and out of the cell from an area of higher concentration to an area of lower concentration.

cell cycle

the three distinct stages (interphase; mitosis; and cytokinesis) through which eukaryotic cells move as they grow and divide.

interphase

the stage in which cells grow; perform their specific functions; produce more organelles; and replicate their DNA.

mitosis

the stage of the cell cycle in which the DNA in the nucleus is divided.

cytokinesis

the stage in the cell cycle when the rest of the cell—such as cytoplasm; organelles; and cell membrane—is divided to form two new identical daughter cells.

daughter cell

one of two genetically identical cells produced after cell division.

Mitochondria

Tiny power plants that make energy for the cell to use.

prophase

the first stage of mitosis in which the chromosomes become visible and the nuclear membrane dissolves.

chromosome

a structure in the cell nucleus made up of a portion of the cell’s DNA condensed into a structure visible under a light microscope.

chromatid

one of two identical strands of DNA that make up a chromosome.

centromere

the structure that holds chromatids together as chromosomes.

metaphase

the second stage of mitosis in which the chromosomes line up in the middle of the cell.

anaphase

the third phase of mitosis in which the sister chromatids separate into daughter chromosomes and each moves toward opposite ends of the cells.

telophase

the final phase of mitosis in which the chromatids unwind and a nuclear membrane reforms around the chromosomes at each end of the cell.

cancer

a broad group of diseases that result in uncontrolled cell division.

tumour

a mass of cells that continue to grow and divide without any obvious function in the body.

benign tumour

a tumour that does not affect surrounding tissues other than by physically crowding them.

malignant tumour

a tumour that interferes with the functioning of surrounding cells; a cancerous tumour.

metastasis

the process of cancer cells breaking away from the original (primary) tumour and establishing another (secondary) tumour elsewhere in the body.

mutation

a random change in the DNA.

carcinogen

any environmental factor that causes cancer.

Pap test

a test that involves taking a sample of cervical cells to determine if they are growing abnormally.

biophotonics

the technology of using light energy to diagnose; monitor; and treat living cells and organisms.

specialized cell

a cell that can perform a specific function through changes in structure and gene expression.

homeostasis

the process of keeping internal conditions stable within a living organism.

tissue

a group of similar cells working together to perform a specific function.

organ

a structure made of multiple tissue types working together to coordinate a specific task.

organ system

multiple organs coordinating a major life function.

Nucleus

The control center or brain of the cell that holds DNA instructions.

Cytoplasm

A wet, jelly-like fluid that fills the inside of the cell

chromosome

a thread-like structure located inside the nucleus of animal and plant cells.

Chromosome purpose

Chromosomes act as packages for your genetic code, holding the instructions that tell your body how to grow, develop, and function

chromatid

one of the two identical halves of a replicated chromosome