The skin of the bright orange south american toad secretes a lethal neurotoxin. assume that the toxin is produced by an enzyme encoded by a gene that has two alleles: t (dominant, wild-type enzyme/toxin) and t (recessive, no enzyme/toxin produced). the neurotoxin is secreted by means of a protein s produced by the wild-type gene s. the recessive allele s does not produce protein s (thus no secretion of the toxin can occur). a toad that cannot manufacture the enzyme/toxin and is heterozygous for the secretion gene is mated with a toad that cannot secrete the toxin and is heterozygous for the enzyme/toxin gene. what fraction of the progeny will be poisonous to the touch, that is, able both to manufacture and to secrete the toxin? use probability to solve the problem.

Will mark brainliest i only need the ! 1.use ten beads and a centromere of one color to construct the long chromosome. use ten beads and a centromere of a second color to construct the second chromosome in the long pair. make a drawing of the chromosomes in the space below. 2. for the second pair of chromosomes, use only five beads. 3. now model the replication of the chromosomes. make a drawing of your model in the space below. part b: meiosis i during meiosis i, the cell divides into two diploid daughter cells. 4. pair up the chromosomes to form tetrads. use the longer tetrad to model crossing-over. make a drawing of the tetrads in the space below. 5. line up the tetrads across the center of your “cell.” then model what happens to the chromosomes during anaphase i. 6. divide the cell into two daughter cells. use the space below to make a drawing of the result. part c: meiosis ii during meiosis ii, the daughter cells divide again. 7. line up the chromosomes at the center of the first cell, one above the other. separate the chromatids in each chromosome and move them to opposite sides of the cell. 8. repeat step 7 for the second cell. 9. divide each cell into two daughter cells. use the space below to make a drawing of the four haploid cells

The transport tubes for food coming down the plants are called?

What kinds of molecules can pass through the cell membrane without any problem?