Which of the following is correct about mutations and genetic variation? It must be present in a population before natural selection can act upon the population.
It arises in response to changes in the environment.
It tends to be reduced when diploid organisms produce gametes and reproduce.
It is created by the direct action of natural selection.

Use this dichotomous key for insect identification to identify the insect shown. 1. a. insect has one pair of wings. order diptera b. insect has two pairs of wings. go to #2 2. a. front wings thicker in texture than hind wings go to #3. b. front and hind wings are same texture throughout. go to #4 3. a. front wings are short order dermaptera b. front wings cover entire abdomen order coleoptera 4. a. wings with scale on all parts of their area. order lepidoptera b. wings without scales go to #5. 5. a. hind wings smaller than front wings. order ephemeroptera b. front and hind wings nearly equal in size. order odonata the insect pictured is in the order diptera. ephemeroptera. coleoptera. odonata.

Genetic disorders can result when sister chromatids fail to seperate properly. during what phase is this problem most likely to occur?

Aquaternary consumer species would be expected to have a smaller population than a secondary consumer species. select the best answer from the choices provided t f