Genetic crosses (AQA GCSE Biology Combined Science): Flashcards
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What do genetic crosses predict?
What do genetic crosses predict?
Traits offspring inherit from parents
What are alleles?
What are alleles?
Different versions of the same gene
How are dominant alleles written?
How are dominant alleles written?
Capital letters (e.g., R)
How are recessive alleles written?
How are recessive alleles written?
Lowercase letters (e.g., r)
What does heterozygous mean?
What does heterozygous mean?
Two different alleles for a trait
What is a Punnett square?
What is a Punnett square?
Grid showing all possible genetic combinations
How many recessive alleles needed to show a recessive trait?
How many recessive alleles needed to show a recessive trait?
Two (one from each parent)
How do dominant alleles affect recessive alleles?
How do dominant alleles affect recessive alleles?
Dominant alleles mask recessive ones
Purple flower probability from Rr × Rr
Purple flower probability from Rr × Rr
= 0.75 = 75% (3:1 ratio)
What are four ways to express probability?
What are four ways to express probability?
Fractions, decimals, percentages, ratios