29. Heredity

An allele that exerts its effects whenever it is present is:

If the two alleles for a particular gene are identical the gene pair is:

If an individual is homozygous for a particular trait:

If an allele must be present on both the maternal and paternal chromosomes to affect the phenotype, the allele is said to be 

(a) Dominant

(b) Recessive

(c) Complementary

(d) Heterozygous

Distinguish between the following paired terms: 

(a) genotype and phenotype, 

Match each of the following key terms (a–i) with its description

below:

Key:

(a) alleles

(b) autosomes

(c) dominant allele

(d) genotype

(e) heterozygote

(f) homozygote

(g) phenotype

(h) recessive allele

(i) sex chromosomes

____ (1) genetic makeup

____ (2) how genetic makeup is expressed

____ (3) chromosomes that dictate most body characteristics

____ (4) alternate forms of the same gene

____ (5) an individual bearing two alleles that are the same for a particular trait

____ (6) an allele that is expressed whether in single or double dose

____ (7) an individual bearing two alleles that differ for a particular trait

____ (8) an allele that must be present in double dose to be expressed

Compare and contrast amniocentesis and chorionic villus sampling as to the time at which they can be performed and the techniques used to obtain information on the fetus’s genetic status.