Down syndrome in humans may result from. A a person inheriting a recessive allele. B sickle-shaped cells becoming stuck in blood vessels. c an extra copy of chromosome 21. D blood failing to clot properly.

Aparent with freckles is crossed with a parent without freckles. the punnett square shows the possible genotypes and phenotypes of the offspring. which statement accurately describes the probability of phenotypes? a.the offspring are more likely to have freckles. b.the offspring are more likely to have no freckles. c.the likelihood of the offspring having freckles and not having freckles is the same. d.the likelihood of the offspring having freckles and not having freckles cannot be determined.

Witch theory suggests all living things are made up of cell or cells

Which process is represented a.) deletion b.) nondisjunction c.) translocation d.) insertion