Cells of the immune system are able to respond to the presence of invading organisms because they recognize the?

a. antigens on invaders
b. antibodies on pathogens
c. dna pattern in the nuclei of viruses
d. antibodies released from microbes

Which sequence represents a cross section of the bilayera hydrophilic head, hydrophobic tail, hydrophobic tail, hydrophilic headb hydrophobic tail, hydrophilic head, hydrophobic tail, hydrophilic headc hydrophobic head, hydrophilic tail. hydrophilic tail, hydrophobic headd hydrophilic tail, hydrophobic head, hydrophobic head, hydrophilic tail

This is due ! matching pairs of chromosomes from parents are called a. homologous chromosomes b. heterozygous chromosomes c. herterogenes d. homologous bands

Aresearcher has developed two stains for use with seed plants. one stains sporophyte tissue blue; the other stains gametophyte tissue red. if the researcher exposes pollen grains to both stains, and then rinses away the excess stain, what should occur? a) the pollen grains will be pure red.b) the pollen grains will be pure blue.c) the pollen grains will have red interiors and blue exteriors.d) the pollen grains will have blue interiors and red exteriors.