Sbi3U Exam Review
Biology Exam 2013 - Review
UNIT: PATERNS OF INHERITENCE
Describe Mendel’s experiments: * Chose a female parent; chooses a male parent; pollen is collected from the stamens and dusted onto the female parent stigma; pollen fertilizes the eggs. The ovary develops into the pod and eggs develop into the peas; when peas are planted they develop into pea plants.
Why Pea Plants? * Easily obtained * Grown quickly; several generation of peas can be observed * Traits are easily visible * Pea flower is closed. This prevents cross-pollination.
Relationship between Dominant and Recessive Traits:
Dominant: the form of a trait that always appears when an individual has an allele for it
Recessive: the form of a trait that only appears when an individual has two alleles for it
Trait: a specific characteristic or feature exhibited by an organism
True breeding: organisms that exhibit the same traits, generation after generation
Cross: the fertilization of a female gamete of specific genetic origin with a male gamete of specific genetic origin
Monohybrid crosses: a cross of two individuals that differ by one trait
Allele: one or two more forms of a gene What does the law of dominance state? How do Mendel’s experiments prove this? * The law of dominance states that if a dominant allele is present, only the dominant form of the trait will be expressed. * Proved this through the recessive green trait and the dominant yellow trait Homozygous and heterozygous and genotype and phenotype: * Homozygous: an organism that has two identical alleles of a gene; i.e. (YY or yy) * Heterozygous: an organism that has two different alleles of a gene; (Yy) * Genotype: the combination of alleles for any given trait, or the organism’s entire genetic make-up * Phenotype: the physical and physiological traits of an organism
What is the law of random segregation? * Traits are determined by pairs of alleles that
UNIT: PATERNS OF INHERITENCE
Describe Mendel’s experiments: * Chose a female parent; chooses a male parent; pollen is collected from the stamens and dusted onto the female parent stigma; pollen fertilizes the eggs. The ovary develops into the pod and eggs develop into the peas; when peas are planted they develop into pea plants.
Why Pea Plants? * Easily obtained * Grown quickly; several generation of peas can be observed * Traits are easily visible * Pea flower is closed. This prevents cross-pollination.
Relationship between Dominant and Recessive Traits:
Dominant: the form of a trait that always appears when an individual has an allele for it
Recessive: the form of a trait that only appears when an individual has two alleles for it
Trait: a specific characteristic or feature exhibited by an organism
True breeding: organisms that exhibit the same traits, generation after generation
Cross: the fertilization of a female gamete of specific genetic origin with a male gamete of specific genetic origin
Monohybrid crosses: a cross of two individuals that differ by one trait
Allele: one or two more forms of a gene What does the law of dominance state? How do Mendel’s experiments prove this? * The law of dominance states that if a dominant allele is present, only the dominant form of the trait will be expressed. * Proved this through the recessive green trait and the dominant yellow trait Homozygous and heterozygous and genotype and phenotype: * Homozygous: an organism that has two identical alleles of a gene; i.e. (YY or yy) * Heterozygous: an organism that has two different alleles of a gene; (Yy) * Genotype: the combination of alleles for any given trait, or the organism’s entire genetic make-up * Phenotype: the physical and physiological traits of an organism
What is the law of random segregation? * Traits are determined by pairs of alleles that