SCIENCE QUIZ FEB 29
phenotype
organisms outward/physical appearance
genotype
organisms genetic characteristics, genes
allele
one pair of matching genes, one from each parent
Dominant
an ellele that is expressed even if only one copy is present (Tt, or Rr= capitol is dom)
recessive
an allele that is expressed when 2 copies are present (Tt or tt= lower case t is rec)
homozygous
having 2 identical alleles for a genetic trait (TT-dom or tt-rec)
heterozygous
having 2 different alleles for a genetic trait (Tt)
what is a gene?
basic human DNA, unit of heredity, used to determine how offspring could/can be
what is a chromosome?
a threadlike structure, carries genetic information in the form of genes. we have 23 pairs, 46 all together
name some genetic disorders
1. down syndrome 2. fragile X syndrome 3. klinefelter syndrome 4. turner syndrome