Inheritance

1. refers to the presence of two complete sets of chromosomes in an organism’s cells
7. alternate forms of the same gene
8. passed from parents to offspring and contain the information needed to specify physical and biological traits
9. both alleles are identical for the trait
15. type of mutagen, cancer-causing _____.
16. a DNA or RNA sequence of three nucleotides (a trinucleotide)
17. change in structure of a gene or chromosome number
18. a type of mutation that involves the loss of one or more nucleotides from a segment of DNA
19. type of mutagen; e.g. X-rays
20. trait that is expressed only under homozygous condition

2. physical trait of an organism
3. Down's syndrome is caused by ______ 21.
4. the presence of a single set of chromosomes in an organism’s cells
5. two different alleles for the trait
6. describes alleles that contributes equally to the physical trait
10. type of mutation where red blood cells from crescent or ____ shaped cells
11. genetic makeup of an organism
12. a reproductive cell of an animal or plant
13. trait that is fully expressed under both homozygous and heterozygous conditions
14. one of the four nucleotide bases in DNA