Answer:
By counting stars.
Explanation:
During the late eighteenth century, there was an astronomer - William Herschel who tried to estimate the size as well as shape of the galaxy by on the sky. It was the time when astronomers didn't even know that there exist some galaxies outside the milky way. He counted all the stars and created a map of the galaxy.
However, in that attempt he didn't realize that stars he was counting were not clear from his view. With that attempt of incorrect nature, he concluded his work as, the galaxy is disk-shaped, flat and contains sun at the center. Today, when the astronomers got a perfect idea of the vastness of the universe and galaxies, we are in a position to say that Herschel's idea of the galaxies was very tiny and underestimated.
They are female because they have two X chromosomes (as you can see at the bottom right of the picture) If they were male they would have one X chromosome and one Y chromosome.
(True)-After one week, seedling height was taken as a measure of plant growth.
The correct answer to this question is that:
The idea of Karyotyping is that it helps us to know the sex of a person and it gives us information whether there are chromosomal disorder or not. As a whole, it won't tell us the traits of a person because those traits are acquired how he or she interacts with the society.