Which process can be a source of genetic variation? a. copying of chromosomes b. binary fission c. mitosis d. crossing over

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.

Group control group #1 experimental group yes yes yes control group #2 no new drug orange juice bed rest no yes no yes ves which of the following is the best explanation of why a second control group was included in this experiment? o a. to provide the volunteers in the study with something to drink o b. to prove that the common cold cannot be cured c. to confuse anyone who is trying to steal their new drug and sell it as their own invention o d. to researchers conclude that results are related to the new drug and not to the orange juice submit e previous

Viruses can be transmitted through air, water, food, insect bites, and direct skin contact. once a virus gains entry into the body, it invades a host cell in order to? a. synthesize antibodies for defense b. deactivate the host cell's defenses c. access cell processes for reproduction d. metabolize host proteins and grow