Frederic griffith discovered transformation in his experiments on mice and  pneumococcus  bacteria. he injected the mice with combinations of harmless, r-strain bacteria and disease-causing s-strain bacteria. which combination of bacteria killed the mice and showed that transformation occurred?

a.

heat-killed r-strain and live s-strain

b.

heat-killed s-strain and live r-strain

c.

heat-killed bacteria of both strains

d.

live bacteria of both strains

Is a hamster and guinea pig part of the same species ?

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.

Can a trait be both polygenic and have multiple alleles? explain why or why not.