Make ts and ls of fresh cucurbita stem tissue. stain with aniline blue. callose deposits surrounding sieve pores of sieve-tube members will stain blue. observe the numerous sieve areas on both lateral and end walls. look especially at the sieve plates and at the distribution of sieve pores and callose. does callose also surround pores in the lateral sieve areas? make a detailed drawing of one sieve plate. also, sketch several sieve-tuber members and companion cells as they appear in this freshly stained material.

Which of these serves as a reference for comparison during a scientific investigation? a)outcome variable (dependent variable) b) test variable (independent variable) c)control group d)hypothesis

What are some possible short and long term medical concerns for crew members on longer space exploration trips

Examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. polyploidy is creating new species. the two populations are not interbreeding freely. hybrid offspring of the two populations begin to appear. one species will increase into a population size twice as large as the other species.