Identify a primary producer, a primary consumer, secondary consumer, tertiary consumer and quaternary consumer.

Where do homologous chromosomes exchange genetic material through crossing over?               a.  chlorophyll    b.  centrosomes    c.  centromeres    d.  chiasma

Which conditions are necessary for natural selection to occur? select all of the answers that apply. a. inheritable adaptations vary among individuals. b. the population size is increasing. c. more individuals are born than can survive. d. fitness varies among individuals. e. the environment changes suddenly and drastically.

Which must be kept in mind when determining if an explanation is correct? check all that apply.which must be kept in mind when determining if an explanation is correct? check all that apply.