autotroph/  heterotroph - an autotroph is an organism which makes its own food (like a plant);  a heterotroph is an organism that must eat other organisms for its energy needs

 trophic level:  the position of an organism in an ecosystem related to its feeding habits; e.g.: producer, primary consumer, secondary consumer, etc.

carbohydrate - a sugar or starch; the source of energy in many foods; chemical formula contains carbon, hydrogen and oxygen

calorie - the amount of heat energy needed to raise the temperature of one milliliter of water one degree Celsius

herbivore, carnivore, omnivore - consumers in a food web:  herbivores eat producers (plants). carnivores eat meat (other consumers), omnivores (like bears and humans) eat both plants and animals

reproductive potential - the number of offspring that an individual might possibly give birth to 

limiting factor - any influence which reduces the reproductive capacity of a population

carrying capacity- the ability of an ecosystem to sustain (keep alive) a certain number of individuals

"10% rule" - on average, only 10% of energy and matter consumed by an organism at a lower trophic level is passed on to the next higher consumer level because most energy is used by any given organism to perform life processes.

detritivore - an organism like a worm or beetle that eats dead material (detritus) but doesn't break the material down into its simplest form (and is therefore not referred to as a decomposer in our book)

 

 

  matter - the substance that anything is made of; molecules and atoms, "building blocks," chemicals

 

  energy - the ability to do work; comes in many forms - chemical energy, heat energy, electrical energy, etc.

 

 

 

 

  feature - a structure, characteristic or behavior of an organism, such as eye color, fur pattern, or timing of migration, which helps to identify the organism as a certain species

 

  trait - the specific way a feature is expressed in an individual:  for example, eye color is a feature; blue eyes are a trait

 

 variation - the range of differences in a trait in any population;  for example, there are variations in the color of walking sticks:  brown, green-brown and green.

Heredity is the passing of information from one generation to the next.

 

 ratio- a comparison of two or more numbers (written with a colon:  2:2 (read "a ratio of two to two")

 

 DNA - deoxyribonucleic acid; the complex chemical, of which chromosomes are made, that carries genetic information to the next generation 

 

  chromosome - a structure in a cell's nucleus that is made of DNA and which transfers hereditary information to the next generation  (genes are found on chromosomes) 

 

  gene - a section of a chromosome that carries a chemical code for features of organisms 

 

  dominant, recessive -  in genetics, dominant refers to a gene that is expressed or shows up whenever it is present and recessive is the form of the gene that is expressed only when no dominant gene is present 

 

  genotype, phenotype - genotype refers to the letters that represent the genes of a trait of an organism, for example:  TT is the genotype for tall pea plants.  Phenotype means the trait that is expressed, for example: 'tall' is a phenotype in pea plants 

An organism’s particular combination of paired alleles is its genotype; the traits produced by those alleles result in the organism’s phenotype.

 

allele - a form of a gene, dominant or recessive, that is responsible for hereditary variation.

 

  Punnett square -  a diagram which shows the possible offspring genotypes when two particular parents breed

 

  heterozygous gene, homozygous gene - heterozygous genes have two different alleles, one dominant and one recessive, for example: Tt, Aa, Ff; homozygous genes have two identical alleles, for example, both dominant or both recessive: TT, aa, FF, ff

 

  genome - the complete set of genes of an organism. The human genome project has cataloged 30000 human genes.

 

  heredity - the passing on of traits from one generation to the next

 

  partial dominance - type of inherited characteristic in which a heterozygous gene  results in a trait unlike the dominant trait or the recessive trait, for example the larkey fur pattern:  Ff (heterozygous) results in solid patterned fur rather than striped (dominant) or spotted (recessive).

 

  mitosis, meiosis -  two types of cell division (reproduction).  Mitosis occurs in all body cells and results in two complete duplicate cells; meiosis creates sex cells with only half of each chromosome pair

 

  natural selection - process in nature that allows well-adapted organisms to survive and reproduce and reduces the probability that poorly-adapted organisms will survive

 

  selective breeding - humans choosing to breed certain organisms for their beneficial characteristics