Question 1 A substance was analysed and was found to have a boiling point of 450 °C.
At room temperature it is a soft grey solid.
Which temperature could be the melting point of a pure sample of the substance?
A. -12 °C
B. 56 °C to 72 °C
C. 250 °C to 275 °C
D. 142 °C
[1 mark]

Which traits do human embryos have that link them to a common ancestor with fish and reptiles? a. scales and tail b. gill slits and scales c. tail and gill slits d. hair and tail

Which atom or ion is the largest? 0 a. 0 0 0 0 e. li

Effect of rotenone and antimycin a on electron transfer rotenone, a toxic natural product from plants, strongly inhibits nadh dehydrogenase of insect and fish mitochondria. antimycin a, a toxic antibiotic, strongly inhibits the oxidation of ubiquinol. (a) explain why rotenone ingestion is lethal to some insect and fish species. (b) explain why antimycin a is a poison. (c) given that rotenone and antimycin a are equally effective in blocking their respective sites in the electron-transfer chain, which would be a more potent poison? explain.