Why is it important to prevent thermometer from resting no the bottom of the test tube?

Ascientist is studying muscle twitches in chicken quadriceps. to activate the muscle, he needs to provide stimulus to the

Joe is breeding cockroaches in his dorm room. he finds that the average wing length in his population of cockroaches is 4 cm. he chooses the six cockroaches that have the largest wings; the average wing length among these selected cockroaches is 10 cm. joe interbreeds these selected cockroaches. from earlier studies, he knows that the narrow-sense heritability for wing length in his population of cockroaches is 0.6. a. calculate the selection differential and expected response to selection for wing length in these cockroaches. b. what should be the average wing length of the progeny of the selected cockroaches?

Which of the following sex and generation combinations directly produces the pollen tube of angiosperms? a) male gametophyteb) female gametophytec) male sporophyted) female sporophyte