Question

content practice a
lesson 2
understanding inheritance
directions: on the line before each definition, write the letter of the term that matches it correctly. each
term is used only once.
_____ 1. threadlike structures in cells a. dominance
_____ 2. contain instructions for traits b. pedigree
_____ 3. two different forms of a gene c. genotype
_____ 4. outward appearance d. heterozygous
_____ 5. determines outward appearance e. chromosomes
_____ 6. represented by uppercase letters f. codominance
_____ 7. represented by lowercase letters g. homozygous
_____ 8. rr h. incomplete dominance
_____ 9. rr i. genes
_____ 10. shows possible outcomes of genetic crosses j. environmental factors
_____ 11. shows inherited traits in a family k. alleles
_____ 12. produces a blend of the parents’ phenotypes l. multiple alleles
_____ 13. when both alleles are expressed m. recessiveness
_____ 14. determines human blood type n. polygenic inheritance
_____ 15. when multiple genes determine a phenotype o. punnett square
_____ 16. can sometimes influence expression of genes p. phenotype
genetics
31

Explanation:

1. Chromosomes are threadlike structures in cells, so 1 matches E.
2. Genes contain instructions for traits, so 2 matches I.
3. Alleles are two different forms of a gene, so 3 matches K.
4. Phenotype is outward appearance, so 4 matches P.
5. Dominance determines outward appearance (dominant traits show), so 5 matches A.
6. Dominant alleles are represented by uppercase letters, related to dominance, so 6 matches A (dominance - dominant alleles uppercase).
7. Recessive alleles are represented by lowercase letters, related to recessiveness, so 7 matches M.
8. RR is homozygous (same alleles), so 8 matches G.
9. Rr is heterozygous (different alleles), so 9 matches D.
10. Punnett square shows possible outcomes of genetic crosses, so 10 matches O.
11. Pedigree shows inherited traits in a family, so 11 matches B.
12. Incomplete dominance produces a blend of parents' phenotypes, so 12 matches H.
13. Codominance is when both alleles are expressed, so 13 matches F.
14. Multiple alleles determine human blood type (ABO has multiple alleles), so 14 matches L.
15. Polygenic inheritance is when multiple genes determine a phenotype, so 15 matches N.
16. Environmental factors can sometimes influence gene expression, so 16 matches J.

Answer:

s:

1. E
2. I
3. K
4. P
5. A
6. A
7. M
8. G
9. D
10. O
11. B
12. H
13. F
14. L
15. N
16. J