Biology 6.2.1 Flashcards
What is ‘Variation’?
Variation is Defined as Differences Between Individuals of the Same Species.
What is ‘Phenotypic Variation’?
Phenotypic Variation is the Difference in Physical Features / Attributes Between Individuals of the Same Species.
Phenotypic Variation can be Caused in 2 Main ways: (3)
-Genetic Variation.
-Environmental Variation.
-Combination of Genetic & Environmental Variations.
Common Examples of Genetic Variation in Humans Include: (5)
-Blood Group.
-Eye Colour.
-Gender.
-Ability to Roll Tongue.
-Free or Fixed Earlobes.
What are the Main Environmental Factors that Can Affect the Characteristics of Organisms within a Species? (5)
-Climate.
-Diet.
-Accidents.
-Culture.
-Lifestyle.
What Affect will the Environmental Factor ‘Accidents’ Have on the Organism?
It may leave Scars.
What Affect will the Environmental Factors ‘Eating too Much, & Not Leading an Active Lifestyle’ Have on the Organism?
Weight Gain.
What Affect will the Environmental Factor ‘Being Raised in a Certain Country’ Have on the Organism?
Speak a Certain Language, with a Certain Accent.
What will happen to a Plant that is in the Shade of a Big Tree?
A Plant in the Shade of a Big Tree Will Grow Taller, to Reach More Light.
Some Features of a Person Vary, because of a Combination of ___ & ___ Factors.
Genetic, Environmental.
Explain an Example of a Feature in Humans that Varies, Based on a Combination of Both Genetic & Environmental Factors. (2)
-Genetic Factor: Tall Parents will Pass Genes to their Children for Height. Their Children have the Genetic Potential to also be Tall.
-Environmental Factor: However, if their Diet is Poor, & they Don’t Lead an Active Lifestyle, they will not Grow very well.
Genes Decide what Characteristics we ___, whereas the Surrounding Environment will Affect how these Inherited Characteristics ___ throughout our Lives.
Inherit, Develop.
There is Usually ___ Genetic ___ Within a Population of a Species.
Extensive, Variation.
What do all Genetic Variants arise from?
All Genetic Variants arise from Mutations.
What are ‘Mutations’?
Mutation are Random Genetic Changes that Occur Continuously.
Most Mutations Have no ___ on the ___. Why is this?
Effect, Phenotype. This is because the Protein that a Mutated Gene Produces may Work just as well as the Protein from the Non-Mutated Gene.
Very Rarely, Mutations Lead to the Development of new ___, and so new ___. If they do, most only have a ___ Effect on the Organism overall.
Allele, Phenotype, Small.
What may a Mutation that Affects the Phenotype of an Organism Lead to?
Occasionally, the new Allele, (Caused by the Mutation) that Affects the Phenotype, Gives the Organism a Survival Advantage over other Members of the Species.
What may happen if the new Phenotype (Caused by a Mutation) is Better Suited to an Environmental Change?
If the New Phenotype (Caused by a Mutation) is Suited to an Environmental Change, it Can Lead to a Relatively Rapid Change in the Species.
Explain an Example of when a New Phenotype (Caused by a Mutation) has led to a New Species. (4)
-A Moth Develops a Mutation, Leading to a Change in its Colour. (Mutation Causes New Allele, Causes New Phenotype).
-This Makes it Blend in Better with the Tree Bark it Lives on, & Less Visible to Predators, therefore Increasing Rate of Survival.
-This Moth has a Survival Advantage, & Breeds More Frequently, therefore Increasing its Chance of Passing on the Mutated Phenotype to the Next Generation of Moths.
-The New Colour Quickly Spreads Throughout the Species.
