Science Bowl - Life Science

abiotic

having to do with nonliving things

adaptation

a change that makes an organism more suited to its environment

allele

a form of a gene

anatomy

the physical structure and form of an organism

artificial selection

the breeding of organisms by humans in order to achieve desired traits

asexual reproduction

reproduction without genetic variation

bacteria

a type of microscopic organism without organelles that can often cause disease

biodiversity

the state of having a variety of genes or species

biotic

having to do with living things

cell membrane

the selectively permeable barrier between the cytoplasm of a cell and its external environment

artery

a thick-walled blood vessel that carries mostly oxygen-rich blood from the heart to the rest of the body

capillary

a tiny, thin-walled blood vessel that forms a dense network bringing blood to body cells

cell theory

the theory that all living things are composed of living units called cells

cell wall

the rigid structure, composed of cellulose or chitin, outside of the cell membrane that helps provide support to plant and fungal cells

chloroplast

the organelle found in plant cells that is the site of photosynthesis

chromosome

the thick, threadlike unit of storage of DNA

cilia

thin, hairlike appendages found on the cell membrane of cells that assist in movement

circulatory system

the organ system in mammals that carries nutrients and wastes throughout the body

codominance

a genetic situation in which neither allele is dominant and both are expressed in the organism's phenotype

commensalism

a symbiotic relationship in which one organism is helped while the other is not affected

cytoplasm

all of the cell's contents inside of the cell membrane, including organelles but excluding the nucleus

cytosol

the gel-like material of the cytoplasm that surrounds the organelles and contains particles such as proteins and RNA

dependent variable

the variable that is affected by the independent variable, or the response variable

digestive system

the organ system that breaks down food for their nutritional components and absorbs nutrients into the body

DNA

deoxyribonucleic acid, the molecule that stores genetic information in living things

dominance

a genetic situation in which one allele is expressed in the organism's phenotype over another allele

ecosystem

the interacting system of organisms and the environment

embryology

the study of embryos, which are developing organisms that have yet to be born or hatched

endoplasmic reticulum

a network of tubules within a cell that helps transport materials and is involved in protein synthesis

evolution

the gradual change in the gene pool of a species over time

excretory system

the organ system that is responsible for getting rid of waste from cellular functions to maintain homeostasis

experimental control

a group in an experiment that has known parameters so that it can be compared to groups that receive experimental treatment

flagella

long, whiplike appendages on the outside of a cell that assists in cellular movement

gamete

a sex cell, that is, a cell with half the usual number of chromosomes that participates in sexual reproduction

gene

a region of DNA that transmits traits from one generation to the next

genetic variation

the differences in genes and DNA within a population or species

genotype

the specific alleles for a gene possessed by an organism

Golgi body

an organelle involved in packaging and export of materials from the cell

heredity

the transfer of inheritable traits from one generation to the next

heterozygous

the condition of having two alleles of different types for a single gene

homozygous

the condition of having two alleles of the same type for a single gene

hypothesis

a testable guess based on observable evidence; the second step of the scientific method

immune system

the organ system responsible for protecting the body from pathogens

incomplete dominance

a genetic condition in which neither allele is expressed over the other, resulting in an intermediate phenotype

independent variable

the variable that is manipulated by the scientist in an experiment

index fossils

fossils of known age that don't change much with time - are used to determine the age of other fossils in the same rock strata

law

an accepted description of a physical phenomena that is always true

mass

a measure of how much matter or substance is in an object, measured in kilograms

meiosis

a process in which a single cell nucleus splits to become four cell nuclei, each with half of the genetic material of the original cell

mitochondria

the organelle in which cellular respiration takes place

mitosis

a process in which a single cell nucleus splits to become two cell nuclei with identical genetic material

mutation

a change in the genetic material of a cell

mutualism

a symbiotic relationship in which both organisms benefit

nucleus

the organelle that houses DNA

organ

a group of tissues that work together to perform a function

organ system

a group of organs that work together to perform a function

organelle

a subcellular component that is isolated from the cytoplasm by a membrane

parasitism

a symbiotic relationship in which one organism is harmed and the other, which is dependent on the first, is helped

phenotype

the physical apperance of an organism

photosynthesis

a set of chemical reactions that convert light energy, water, and carbon dioxide into glucose and oxygen

predation

a relationship in which one organism consumes the other for energy

Punnett square

a way of organizing genes and alleles to determine the genotypes and phenotypes of offspring

recessive

not expressed in the phenotype of a heterozygous individual

reproduction

creation of the next generation of organisms

resources

things organisms need for survival and reproduction

respiratory system

the organ system that is responsible for exchanging gas with the environment

ribosome

a subcellular component that makes proteins

scientific method

a systematic approach to solving problems and answering questions used by scientists

sensory receptor

something that gains information from the environment to tell the organism

sexual reproduction

reproduction with genetic variation

symbiotic relationship

a close biological relationship between two different species

theory

an explanation that unifies many different scientific laws

tissue

a group of cells that work together to perform a function

tropism

the tendency to turn towards or away from something in the environment

vaccination

the exposure of an organism to a weakened virus to help that organism gain immunity against that virus in the future

vacuole

the organelle that stores materials

variable

something in an experiment that can change based on environmental and human factors

vein

a type of blood vessel with valves that carries deoxygenated blood back to the heart

virus

a microscopic, almost living thing that can cause disease

zygote

a fertilized egg, or a single cell that can develop into a multicellular organism