| A | B |
|---|
| Reproduction by two parents | sexual reproduction |
| a gene that prevents the expression of another gene | dominant gene |
| cause | affect |
| the selection by humans of the best parents to breed so that the offspring are the best | artificial section |
| male sex cell | sperm |
| permanent change in DNA that occurs when DNA copies itself | mutation |
| female sex cell | eggs |
| a gene whose expression is prevented by a dominant gene | recessive gene |
| process by which sex cells are produced | meiosis |
| threadlike strands found in the nucleus of a cell and made mostly of DNA molecules | chromosomes |
| the shape of DNA | spiralling ladders |
| a section fo DNA that controles one or more traits | gene |
| same | identical |
| process by which a cell's nucleus divides to form two identical nuclei with the same number of chromosomes as the original cell | mitosis |
| they split a part and move | twin chromosomes |
| process by which a cell divises into two nearly equal-sized cells | cell division |
| one kind of molecule that makes up a DNA strand | bases |
| reproduction by one parent | asexual reproduction |
| controls the cell | DNA |
