definitions for Sci 1.9
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| A molecule containing phosphate-sugar-base, found in DNA. | ||
| A sequence of three nucleotide bases found on a DNA strand. | ||
| A term used to describe the structure of DNA; a spiral ladder-shaped helix molecule. | ||
| Two bases making up each rung of DNA; either C-G or A-T. | ||
| A molecule containing phosphate-sugar-base, found in DNA. | ||
| A sequence of three nucleotide bases found on a DNA strand. | ||
| A term used to describe the structure of DNA; a spiral ladder-shaped helix molecule. | ||
| Two bases making up each rung of DNA; either C-G or A-T. | ||
| A base found in DNA which bonds with Thymine. These make a base pair that form "rung" in the DNA structure. | ||
| A base found in DNA which bonds with Guanine. These make a base pair that form "rung" in the DNA structure. | ||
| A base found in DNA which bonds with Cytosine. These make a base pair that form "rung" in the DNA structure. | ||
| A base found in DNA which bonds with Adenine. These make a base pair that form "rung" in the DNA structure. | ||
| A molecule found in the nucleus of cells that codes for an individual's genetic makeup. | ||
| A molecule made up of many repeating units. | ||
| A distinctive inherited feature of an organism. | ||
| Another word meaning characteristic. | ||
| The genetic information that is held in the DNA | ||
| An individual that is able to grow, reproduce, respire etc. (MRS GREN) | ||
| The structural and functional unit that makes up all living things. | ||
| The centre of the cell where the genetic material is found. | ||
| A length of DNA, which holds the genes; thread like structures that are visible before a cell divides. They are found in the nucleus of the cell. Humans have 23 homologous pairs. | ||
| The formation of two or more daughter cells formed from one original cell. | ||
| Copying. | ||
| The new cells that form once a cell has divided. | ||
| A length of DNA found on a chromosome that carries the code for one feature. | ||
| When something is passed on from one generation to another. | ||
| Something which is able to provide a pattern or sequence that can be copied. | ||
| The process whereby DNA makes a complete copy of itself. | ||
| Cell division used for growth and repair - produces two cells identical to the original. | ||
| The type of cell division which produces sex cells/gametes (sperm and eggs; pollen and ova). In animals it happens in the ovaries and testes. Each gamete contains half the genetic information of normal cells (i.e. 23 chromosomes in humans). | ||
| A different form of a gene. Each characteristic has 2 alleles. | ||
| The characteristic that is expressed due to a particular geneotype i.e. what you see. | ||
| The combination of two alleles that an organism has for a particular gene. This is the code for the alleles. | ||
| Two copies of a chromosome that have the same shape and structure and carry the same genes. | ||
| When both alleles are the same eg RR or rr | ||
| When the two alleles are different eg Rr | ||
| The allele which is expressed even if just one is present. | ||
| The allele which is only expressed if the dominant allele is absent. | ||
| Form of reproduction involving the fusion of two gametes from two parents. Produces variation in offspring. | ||
| The sex cells. A cell that contains half the genetic information that has to join with another gamete to form a zygote before further development can occur. | ||
| Gametes formed in the testes and ovaries in animals. | ||
| The gamete/sex cell produced by male animals. | ||
| The male organ in animals that produces male gametes - sperm. | ||
| The gamete/sex cell produced by female animals. | ||
| The female organ that produces the female gametes - eggs. | ||
| The gamete/sex cell produced by the male part of plants. | ||
| The male part of the flower that produces the male gamete - pollen. | ||
| The fusion (joining) of a male gamete and a female gamete to form a zygote. | ||
| A fertilised egg. A single cell containing chromosomes from both the male gamete and the female gamete. | ||
| The differences between individuals, which help a species survive. | ||
| The exchange of genetic material between homologous chromosomes which occurs during meiosis and contributes to genetic variability. | ||
| Name for the process where chromosomes line up in random order at the cell equator during meiosis which results in a random combination of alleles in a particular gamete. | ||
| Variations that can be passed on from parent to offspring. | ||
| Variations that are due to environmental factors. | ||
| Photograph of individual chromosomes of a cell arranged in pairs and showing their size number and shape. | ||
| A grid-like diagram used to make predictions about inheritance. | ||
| A chart that shows the genetic relationships between members of the same family. | ||
| A number expressed as part of a whole number e.g. ⅔ of offspring are blue eyed. | ||
| The ratio/relationship of one part to another e.g. 2 out of every 3 offspring are blue eyed. | ||
| The relationship of one number to another. E.g. 2 blue eyed offspring: 1 non-blue eyed offspring. | ||
| An organism that is homozygous for a trait. | ||
| A breeding test that is carried out to determine the genetic makeup of an organism | ||
| Occurs when the environment "selects" the best phenotypes. Often referred to as "survival of the fittest", as a result the species changes | ||
| A process that is used to breed for specific required traits e.g. cattle with more muscle, flowers with better smell. | ||
| A change in the base sequence of DNA. | ||
| Group of plants or animals differing only slightly from others and capable of interbreeding. | ||
| A population is all the organisms that both belong to the same species and live in the same geographical area. | ||
| The conditions in the environment that can change an organisms appearance e.g. diet, food supply, climate changes, diseases, predators. | ||
| Reproduction involving only one parent that creates genetically identical offspring | ||
| Making a genetically identical copy of an organism. | ||
| Type of variation in which there is a complete range of measurements from one extreme to the other e.g. human height. | ||
| Type of variation where the characteristic fall into a number of distinct classes or categories e.g. human eye colour or tongue rolling. |
