Biology Definitions Part 2

Front 1

Phenotype

Back 1

physical characteristics of an organism

Front 2

Genotype

Back 2

genetic makeup of an organism

Front 3

Meiosis

Back 3

process by which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell

Front 4

Mitosis

Back 4

part of eukaryotic cell division during which the cell nucleus divides

Front 5

Chromosome

Back 5

threadlike structure within the nucleus containing the genetic info that is passed from one generation of the cells to the next

Front 6

Gene

Back 6

sequence of DNA that codes for a protein and thus determines a trait

Front 7

Allele

Back 7

one of a number of different forms of a gene

Front 8

Heterozygous

Back 8

term used to refer to an organism that has two different alleles for the same trait

Front 9

Homozygous

Back 9

term used to refer to an organism that has two identical alleles for a particular trait

Front 10

Dominant Trait

Back 10

a non-linear relationship between different forms (alleles) of a gene and the resultant phenotype

Front 11

Sex Linked

Back 11

gene located on the X or Y chromosome

Front 12

Recessive Trait

Back 12

a non-linear relationship between different forms (alleles) of a gene and the resultant phenotype.

Front 13

Incomplete Dominance

Back 13

situation in which one allele is not completely dominant over another

Front 14

Codominance

Back 14

situation in which both alleles of a gene contribute to the phenotype of the organism

Front 15

Independent Assortment

Back 15

independence segregation of genes during the formation of gametes

Front 16

Law of segregation

Back 16

Mendel's first law, stating that allele pairs separate during gamete formation, and then randomly re-form pairs during the fusion of gametes at fertilization.

Front 17

Punnet square

Back 17

diagram showing the gene combinations that might result from a genetic cross

Front 18

Pedigree chart

Back 18

chart that shows relationships within a family

Front 19

Reservoir

Back 19

A large natural or artificial lake used as a source of water supply

Front 20

Conservation of matter

Back 20

a fundamental principle of classical physics that matter cannot be created or destroyed in an isolated system

Front 21

Beneficial bacteria

Back 21

keeping water clean

Front 22

Ecosystem

Back 22

collection of all the organisms that live n a particular place, together with their non living environment

Front 23

Photosynthesis

Back 23

The conversion of light energy to chemical energy that is stored in glucose or other organic compounds; occurs in plants, algae, and certain prokaryotes.

Front 24

Respiration

Back 24

In aerobic organisms, the intake of oxygen and the liberation of carbon dioxide. (2) In cells, the oxygen-requiring stage in the breakdown and release of energy from fuel molecules.

Front 25

Chloroplast

Back 25

An organelle found only in plants and photosynthetic protists that absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water.

Front 26

Mitochondria

Back 26

An organelle in eukaryotic cells that serves as the site of cellular respiration.

Front 27

ATP

Back 27

An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells.

Front 28

ADP

Back 28

A nucleotide consisting of adenine, ribose, and two phosphate groups; formed by the removal of one phosphate from an ATP molecule.

Front 29

Aerobic respiration

Back 29

Containing oxygen; referring to an organism, environment, or cellular process that requires oxygen.

Front 30

Anaerobic respiration

Back 30

Lacking oxygen; referring to an organism, environment, or cellular process that lacks oxygen and may be poisoned by it.

Front 31

Energy transfer

Back 31

is the transfer of energy from one body to another

Front 32

Chemical bond

Back 32

An attraction between two atoms resulting from a sharing of outer-shell elctrons or the presence of opposite charges on the atoms; the bonded atoms gain complete outer electron shells.

Front 33

Organic compound

Back 33

A chemical comound containing the element carbon and usually synthesized by cells.

Front 34

Carbohydrate

Back 34

A sugar (monosaccharide) or one of its dimers (disaccharides) or polymers (polysaccharides).

Front 35

Conservation of energy

Back 35

A principle stating that energy cannot be created or destroyed, but can be altered from one form to another.

Front 36

Biomass

Back 36

The dry weight of organic matter comprising a group of organisms in a particular habitat.

Front 37

Trophic levels

Back 37

The division of species in an ecosystem on the basis of their main nutritional source. The trophic level that ultimately supports all others consists of autotrophs, or primary producers.

Front 38

Symbiosis

Back 38

An ecological relationship between organisms of two different species that live together in direct contact.

Front 39

Mutualism

Back 39

A symbiotic relationship in which both the host and the symbiont benefit.

Front 40

Predator- Prey

Back 40

An organism that eats other living organisms-An organism eaten by another organism.

Front 41

Limiting factors

Back 41

a factor that controls a process

Front 42

Carrying compacity

Back 42

comparing weight

Front 43

Expotentional population growth

Back 43

Growth in which the rate of increase is not limited by any external factor, but is dependant on the number of individuals and their potential net productivity rate.