1. CST NB Entry #1—DNA
In a strand of DNA, adenine always pairs with ______ and guanine always pairs with _______
A. Thymine, uracil
B. Thymine,guanine
C. Uracil, cytosine
D. Thymine, cytosine

2. NB Entry #2—Genetics
Genes on the Y chromosome are important for the normal development of
A. Both boys and girls
B. Girls only
C. Neither boys nor girls
D. Boys only

3. NB Entry #3—Meiosis
Which describes the cells produced by meiosis?
A. Diploid sex cells
B. Haploid sex cells
C. Haploid body cells
D. Diploid body cells

4. NB Entry #4—Genetic Change
How does fertilization increase genetic variation?
A. By leading to natural selection
B. By causing new mutations to occur
C. by creating new allele combinations
D. by allowing crossing-over to occur

5. NB Entry #5—Genetic Variation
What contributes to genetic variation in sexually reproducing species?
A. Shuffling of genes and chromosomes during gamete formation
B. Mutations creating new life forms
C. variation in environmental conditions
D. all of the above

6. NB Entry #6—Immunity
Which of the following is an example of a non-specific defense
A. Killer T-cell production
B. Cell-mediated immunity
C. humoral immunity
D. the skin