The Punnett square in Figure 7.1 shows a cross between two parents who have the genotype Ss for a genetic disorder caused by a recessive allele such as Sickle Cell disease. What is the probability that their child will carry the Sickle Cell trait? S s
S SS Ss
s Ss ss

0%
100%
75%
25%
50%

Imagine a rocket launching from earth and travelling to the moon. in which order would the rocket pass through the layers of the atmosphere? thermosphere, mesosphere, stratosphere, troposphere troposphere, mesosphere, stratosphere, troposphere thermosphere, stratosphere, mesosphere, troposphere troposphere, stratosphere, mesosphere, thermosphere

If the coding part of an mrna molecule is 1800 nucleotides (bases) in length, this molecule will contain codons and code for a polypeptide that is amino acids long.

Which phrase is the best summary of the model shown? a. the transfer of the sun's energy through trophic levels b. a series of aerobic and anaerobic reactions c. a transformation of light energy into chemical energy d. the breakdown of food molecules