A plant heterozygous for two genes is testcrossed with a plant homozygous recessive for both genes. The offspring have observed counts of 22, 28, 24, and 26 for the four phenotype combinations. The null hypothesis predicts a 1:1:1:1 ratio under independent assortment. Using a critical value of 7.82 (df=3, p=0.05), what is the chi-square value and conclusion?

In a drought study, 100 broad-leaf plants (high SA:V) and 100 needle-leaf plants (low SA:V) are observed. 20 broad-leaf and 60 needle-leaf plants survive. If leaf shape did not affect survival, 40 survivors were expected in each group. Calculate $\chi^2$ and interpret ($\alpha=0.05$, critical value=3.84).

Researchers treat a bacterial culture with lysozyme, an enzyme that degrades peptidoglycan cell walls. Based on the enzyme concentration, they expect 60% of the cells to lyse (burst) and 40% to remain intact. In a sample of 200 treated cells, 130 lysed and 70 remained intact. Using a critical value of 3.84 ($p=0.05$, $df=1$), which choice correctly describes the chi-square ($\chi^2$) analysis?

A testcross is performed to see if genes for two metabolic enzymes assort independently (1:1:1:1 ratio). The observed offspring counts are 45, 45, 35, and 35. Using a critical value of $7.82$ ($p=0.05$), what is the conclusion?

Two genes encoding enzymes for the Krebs cycle are tested for linkage. A chi-square test for independence is performed, resulting in a p-value of $0.03$. Using a significance level of $\alpha = 0.05$, what is the correct biological conclusion?

Researchers investigate whether mitochondrial density (High vs. Low) is independent of tissue type (Muscle vs. Skin). Observed counts are: Muscle/High=$60$, Muscle/Low=$40$, Skin/High=$40$, Skin/Low=$60$ ($n=200$). Using a critical value of $3.84$ ($df=1$, $p=0.05$), what is the correct statistical conclusion?

Researchers investigate if testosterone signaling influences aggression in male fish. They observe 50 intact males and 50 castrated males. Intact males show 40 high-aggression and 10 low-aggression behaviors. Castrated males show 10 high-aggression and 40 low-aggression behaviors. Using a critical value of 3.84 (p=0.05), what is the chi-square result?

Yeast cells exposed to a mating factor are expected to form projections called "shmoos" at a rate of 70%. In a sample of 100 cells, 60 form shmoos and 40 do not. Using a critical value of 3.84 ($\alpha = 0.05$), what is the conclusion?

In a species with 2n = 46, three cell types are examined. Type A cells have 46 chromosomes, Type B cells have 23 chromosomes, and Type C cells have 46 chromosomes. Which conclusion is supported by the data regarding the cell types?

A biologist observes a germ cell undergoing meiosis to produce gametes. Which statement best describes how the chromosome number is reduced from diploid to haploid during this process?