Life Science (genetics, systems, processes)

part 2

biology

the scientific study of living organisms and life processes

organism

an individual living thing

cell

the smallest structural and functional unit of life

unicellular organism

an organism made of one cell

multicellular organism

an organism made of multiple cells

tissue

a group of similar cells working together to perform a function

organ

a structure made of different tissues that perform a specific function

organ system

a group of organs working together to perform major body functions

metabolism

all chemical reactions that occur within a living organism

homeostasis

the process of maintaining stable internal conditions

stimulus

a change in the environment that causes a response

adaptation

an inherited characteristic that helps an organism survive or reproduce

reproduction

the biological process of producing offspring

sexual reproduction

reproduction involving the combination of genetic material from two gametes

asexual reproduction

reproduction involving one parent without the fusion of gametes

growth

an increase in an organism's size or number of cells

development

the process of changes in an organism throughout its life

energy

the ability to do work or cause change

cell theory

the theory that all living things are made of cells, cells are the basic units of life, and cells come from existing cells

cell membrane

a thin, selectively permeable barrier that controls what enters and leaves a cell

cytoplasm

the jelly-like material inside a cell that surrounds its organelles

nucleus

the organelle containing DNA and directing most cell activities

nucleolus

a structure inside the nucleus that helps produce ribosomes

mitochondria

organelles that produce most of a cell's ATP through cellular respiration

ribosomes

structures responsible for making proteins

endoplasmic reticulum (ER)

a network of membranes that helps produce and transport proteins and lipids

rough ER

a membrane network covered with ribosomes that helps make and process proteins

smooth ER

a membrane network that produces lipids and helps detoxify substances

golgi apparatus

an organelle that modifies, sorts, and packages proteins and lipids

lysosome

an organelle containing enzymes that break down waste and worn-out cell parts

vacuole

a membrane-bound compartment used for storing water, nutrients, or waste

chloroplast

an organelle in plants and algae that performs photosynthesis

chlorophyll

the green pigment that absorbs light for photosynthesis

cell wall

a rigid outer layer that provides support and protection to certain cells

cytoskeleton

a network of protein fibers that supports cell shape and movement

prokaryotic cell

a cell without a nucleus or other membrane-bound organelles

eukaryotic cell

a cell containing a nucleus and membrane-bound organelles

plant cell

a eukaryotic cell that typically has a cell wall, chloroplasts, and a large central vacuole

animal cell

a eukaryotic cell that lacks a cell wall and chloroplasts

bacteria

single-celled prokaryotic organisms

atp

the molecule cells use as their main source of usable energy

diffusion

the movement of particles from an area of higher concentration to lower concentration

osmosis

the movement of water across a selectively permeable membrane

passive transport

the movement of substances across a membrane without using cellular energy

active transport

the movement of substances across a membrane using cellular energy

cellular respiration

the process by which cells break down nutrients to produce ATP

aerobic respiration

cellular respiration that uses oxygen to produce ATP

anaerobic process

a biological process that occurs without requiring oxygen

fermentation

a process that regenerates molecules needed for glycolysis when oxygen is unavailable

photosynthesis

the process by which plants and certain other organisms use light to make sugars

cell division

the process in which one cell divides to form new cells

mitosis

the division of a cell's nucleus to produce two genetically identical nuclei

meiosis

cell division that produces haploid cells for sexual reproduction

cytokinesis

the division of a cell's cytoplasm into separate daughter cells

interphase

the stage of the cell cycle when a cell grows, performs normal functions, and copies its DNA

prophase

the stage of mitosis when chromosomes condense and the spindle begins to form

metaphase

the stage of mitosis when chromosomes line up in the center of the cell

anaphase

the stage of mitosis when sister chromatids separate

telophase

the stage of mitosis when new nuclei form around separated chromosomes

haploid cell

a cell containing one set of chromosomes

diploid cell

a cell containing two sets of chromosomes

gamete

a reproductive cell, such as a sperm or egg

stem cell

an unspecialized cell that can develop into certain specialized cell types

genetics

the study of heredity and inherited traits

heredity

the passing of genetic characteristics from parents to offspring

DNA

the molecule that stores genetic information in living organisms

RNA

a nucleic acid involved in using genetic instructions to make proteins

gene

a segment of DNA that contains instructions for a functional product

chromosome

a structure made of DNA and proteins that carries genetic information

allele

an alternative version of a gene

trait

an inherited characteristic or feature of an organism

domainant allele

an allele that can affect a trait when only one copy is present

recessive allele

an allele whose effect is typically expressed when two copies are present

genotype

the genetic makeup or allele combination of an organism

phenotype

the observable characteristics of an organism

homozygous

having two identical alleles for a particular gene

heterozygous

having two different alleles for a particular gene

punnett square

a diagram used to predict possible allele combinations in offspring

mutation

a change in the DNA sequence

genetic variation

differences in genetic information among individuals

gregor mendel

the scientist known as the father of genetics for his experiments with pea plants

fertilization

the fusion of sperm and egg to form a zygote

zygote

the first cell formed when two gametes fuse

inherited trait

a characteristic influenced by genes passed from parents

acquired characteristic

a feature developed during life through environmental influences or experience

genetic engineering

the direct modification of an organism's genetic material

clone

a genetically identical copy of a cell or organism

evolution

the change in inherited characteristics of populations over generations

natural selection

the process in which organisms with advantageous inherited traits reproduce more successfully

charles darwin

the scientist who helped develop the theory of evolution by natural selection

survival of the fittest

the idea that organisms best suited to their environments tend to reproduce more successfully

species

a group of organisms whose members can generally reproduce with one another and produce fertile offspring

adaptation

an inherited characteristic that improves survival or reproduction

extinction

the permanent disappearance of a species

fossil

preserved remains or traces of ancient organisms

taxonomy

the science of naming and classifying organisms

binomial nomenclature

the system of giving each species a two-part scientific name

domain

the broadest major category used to classify life

kingdom

a major taxonomic category below domain

phylum

a classification category below kingdom and above class