Usually blocked fallopian tubes cannot be treated and embryo transplantation is a method which can be used to help a woman become pregnant. - Describe the stages involved in embryo transplantation.

Day 1: The blastocyst begins to hatch out of its shell.

Day 2: The blastocyst continues to hatch out of its shell and begins to attach itself to the uterus.

Day 3: The blastocyst attaches deeper into the uterine lining, beginning implantation

Explanation:

Stage. Days (approx) Events.

4. 5 - 6. attaching blastocyst

5. 7 - 12 (week 2) implantation.

6. 13 - 15. extraembryonic mesoderm, primitive streak, gastrulation

7. 15 - 17 (week 3) gastrulation, notochordal 

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

an organism's phenotype is the  form of a trait  that it  displays. for  flowercolor, a pea  plant  can  display  a phenotype of purple or white flowers. an organism's  genotype  is the alleles of a gene it contains. based on his data, mendel concluded that a phenotype can be  determined  by more than one  genotype.