Q: 112 (CDS-I/2003)

With reference to normal human beings, consider the following statements:
I. In males, testosterone is secreted into the blood by Leydig cells.
II. In females, the cells of the corpus luteum secrete estrogen into the blood.
III. The fertilised ovum gets implanted on the wall of uterus at the blastocyst stage.
Which of these statements are correct?
question_subject: 
Science
question_year: 
2003
question_exam: 
CDS-I
stats: 
0,592,416,128,120,160,600