Which of the following statements are correct regarding female reproductive cycle?
$A$. In non-primate mammals cyclical changes during reproduction are called oestrus cycle.
$B$. First menstrual cycle begins at puberty and is called menopause.
$C$. Lack of menstruation may be indicative of pregnancy.
$D$. Cyclic menstruation extends between menarche and menopause.
Choose the most appropriate answer from the options given below.
$A,C$ and $D$ only
$A$ and $D$ only
$A$ and $B$ only
$A,B$ and $C$ only
Pair of chromosomes in maize
The animals which lay fertilized or unfertilized eggs and whole development takes place outside the body of mother are called
In a practical test, a student has to identify the organisms in which syngamy does not occur. In those organisms the female gamete undergoes development to form new organisms without fertilization. This phenomenon is called $"X"$. Identify the organisms and the phenomenon $"X".$
Oestrus cycle is seen in
What is seen in zygote during embryogenesis ?