Directions: Explain the importance of crossing over. You must use the vocabulary words sister chromatid, tetrad, homologous chromosomes, non-sister chromatid, sexual reproduction.

Which of these is not a function of some membrane proteins ? a.allowing polar molecules to enter the cell b.recognizing other types of cells c.receiving messeges from other cells b.carrying messages to oher cells

How would you describe an allele that be expressed and determines an organisms appearance? a.uncapitalized b.responsive c.recessive d.dominant

Which layer of the eye completely surrounds the eye except for a dark, round opening called the pupil? a. sclerab. corneac. retinad. choroidthe answer is a sclera