When studying animal behavior, the distribution of organisms within a choice chamber can be studied to identify animal preferences. 20 Isopods are placed in a 2-choice choice chamber. A cotton ball dampened with distilled water is placed in Chamber A; A dry cotton ball is placed in Chamber B. After 15 minutes 2 Isopods are located in Chamber B, and 18 isopods are found in Chamber A. Perform the chi-squared test to determine if the distribution of isopods is significant or due to random chance. a) chi-squared is 1.20, no it is not significant
b) chi-squared is 8.42, no its not significant
c) Chi-squared = 12.8, yes it is significant
d) Chi-squared is 18.59, yes it is significant

c

Explanation:

Random distribution of the Isopods should be 50/50 in A and B.

Chi-square = where O = observed frequency and E = expected frequency

Chamber         O                    E             Chi-square

  A                   18                   10             = 6.4

  B                    2                    10             = 6.4

Total Chi-square = 6.4 + 6.4 = 12.8

Degree of freedom = 2 - 1 = 1

Tabulated Chi-square (α = 0.05) = 3.8415

The calculated Chi-square exceeds the critical value, hence, it is significant and not due to random.

The correct option is c.

the food storage products of chrysophytes are oils or the polysaccharide laminarin.   formerly classified as plants, the chrysophytes contain the photosynthetic pigments chlorophyll a and c all but the yellow-green algae also contain the carotenoid pigment fucoxanthin.