Interactive Cloze - Year 11 Science: Genetics and Variation

Genetics is the study of how traits or characteristics are passed on from parents to their children. These __________ can include physical characteristics like height, hair colour and eye ___________as well as functional characteristics like whether ____________ you can roll your tongue or how well your body can withstand cold temperatures. These characteristics can be the same or _______________ from one individual to the next. These differences are known as variation.
Causes of Variation
There are two ___________ of variation: genetic and environmental.
Genetic variation refers to characteristics that have been passed from parents to offspring through sexual reproduction. Sexual_____________ involves the joining together of one sex cell or gamete from the male parent (sperm in _______________; pollen in plants) and one gamete from the ____________ parent (an egg or ovum). Each gamete contains half of the genetic information needed to ______________ a new individual.

This joining of gametes is called fertilisation and the cell that is created as a result ________ a zygote. The zygote contains a full set of genetic information, half of it from each _______________. This explains why children resemble their biological parents. Some examples of characteristics that are determined by your genes include your natural hair colour and the _______________ of your ear lobes. Variation can also be _______________ by things that happen to us _______________ our lifetime. This cause of variation is called environmental variation. One example is whether or not you have pierced ears. Another _______________ is dying or bleaching your hair to change its colour. Some variation has both _______________ and environmental causes. An example of this is height. Whether or not you reach your genetic potential _______________ can be affected by how well-_______________ you are while you are growing up.
The Importance of Variation to the Survival of Species
Because environmental conditions are _______________ changing, the characteristics needed to best survive are always _______________ too. Variation means that in any conditions, there are bound to be at least _______________ individuals with suitable characteristics to _______________ those conditions. This ensures the survival of that species. Without variation, a species is more vulnerable to _______________ extinct.

Contributed by Madeleine Ware.