Science: Biology

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Science: Biology
2010-11-03 03:23:29

Genetic Variation & Humans cont.
Show Answers:

  1. What does genetic variation do?
    Genetic variation provides a lot of different traits. It is essential to the survival of all species as if all individuals were the same, a species would be in danger of extinction.
  2. What is continuous variation?
    Continuous variation is when traits cannot be sorted into distinct classes, but fall into a series of overlapping classes. E.g. Height, nose size, hair length.
  3. What is discrete variation?
    Discrete variation is when traits show distinct or 'either or' variation. E.g. eye color, whether someone can roll their tongue.
  4. What are sex cells called?
    Sex cells are called gametes. Fertilized sex cells and developing embryo are called zygotes.
  5. What do homozygous and heterozygous mean?
    Homozygous means the same (like homosexuals) and heterozygous means different.
  6. Explain dominant and recessive alleles.
    A dominant allele will always be expressed and a recessive allele will only be expressed if the other allele that makes up the gene is recessive.
  7. What does an allele code for?
    An allele codes for a gene.
  8. What are genotype and phenotype?
    Genotype are what alleles make up the gene and Phenotype is the physical expression of the gene.
  9. What is the gamete producing organ called?
    A gonad.