Cells are not essential for--

A: Evaporation

B: Transpiration

C: Guttation

D: All of these

1. Today our ecosystems are affected by changing weather patterns caused mainly by the

A: melting polar ice.

B: increase in temperature.

C: increase in greenhouse gases.

D: increase in global industrial waste.

2. A homozygous trait is defined as

A: the appearance of an organism.

B: an organism that carries two identical alleles.

C: an organism that carries two different alleles.

D: the two letters that make up the organism�s genes.

3. A cross between two traits was made using a punnett square as given below.

R r

R RR A

r Rr B

The genes for A and B are

A: RR, rr.

B: Rr, Rr.

C: Rr, rr.

D: RR, Rr.