Genetics Flashcards
(16 cards)
What is the smallest group in the classification of organisms?
Species
A species can mate together and produce fertile young.
What are variations in the context of species?
Differences between individuals of the same species
Example: height.
What is continuous variation?
Range of varieties between two extremes
Example: height of year 10 pupils; produces a bell-shaped curve known as normal distribution curve.
What is discontinuous variation?
Distinct values
Example: rolling tongue either can or can’t; results can be plotted in a bar graph.
What causes variations?
Combination of genes and environment
A gene is a short length of DNA.
What controls a cell?
Its nucleus
The nucleus contains chromosomes.
What are chromosomes?
Thread-like structures that are divided into genes.
What is a gene?
A short length of DNA
DNA acts as a code for determining inherited characteristics.
What do different genes control?
Different characteristics
Example: hair colour.
What is observed when extracting DNA from a strawberry?
Long thin thread-like structures are visible
They clump together and can be seen floating on the surface.
What is genetic modification?
Replacing a section of DNA from one organism with the DNA of another organism to improve their characteristics.
What are some advantages of GM crops?
Improved quality, taste, colour, size; resistant to disease/conditions; convenience
Cost is also a factor.
What are some disadvantages of GM crops?
Possible side effects to humans, environment, and natural species.
Fill in the blank: A gene is a _______.
short length of DNA.
True or False: Continuous variation produces a bar graph when plotted.
False
Continuous variation produces a bell-shaped curve.
True or False: Discontinuous variation has distinct values.
True.
