Which is not true of eukaryotic cells?
a. a true nucleus contains the chromosomes.
b. eukaryotic cells contain membrane-bounded compartments.
c. they contain ribosomes that are smaller than those of prokaryotic cells.
d. they all contain mitochondria.
e. they contain many organelles in the cytoplasm. b incorrect

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Achange in direction without a change in speed is called velocity

Which of the following is true about the introduction of a non-native species to an environment? (a) they usually adapt quickly so they can have a positive affect on the environment. (b) they can disrupt the environment and cause much damage and devastation to native species. (c) they usually become predators in a food chain and to keep prey populations under control. (d) because the native species are better-adapted to the environment, the non-native species always end up dying out.