class 8th science chapter 10

1. Sex determination
B.Sc. B.Ed. integrated

4. whose scooty could this be?
And why?

5. Video time
• https://youtu.be/dRs0NEY5X9Y
What do you observe from this
video ???

6. Sex determination
• 23 pairs of chromosomes present inside the nucleus of every human
cell.
• These chromosomes have a thread-like structure and they always
occur in pairs.
• The chromosomes help in determining the sex of the child.

8. 
Why sex determination is banned in India?

9. One word ans.
• Q. which chromosome does the unfertilized
egg contains?
• Q. what decides the sex of an unborn child?
• Q. how many sex chromosomes are there in
human cell?

10. what you observed in these pictures?

11. why there is difference in height?

15. How do you enjoy an adrenaline rush?

16. Question
• insufficient levels of
thyroid hormone in
adults cause…….
a)Goiter
b)Tetany
c) myxedema
d)Cretinism
Q. This is not an
endocrine gland
a)Adrenal
b)Pituitary
c) Lacrimal
d)Thyroid

17. Just say yes or no
 Are there hormones in other animals also?
 Have they any role to play in reproduction?

19. Role of hormones in completing the life history of
insects and frogs Insects
• Insect like silk moths and some animals like frogs
undergo the process of metamorphosis which results in
drastic changes in their bodies.
• The insect hormones control the process of
metamorphosis in the insects.

20. ,,
• In frogs, thyroid releases thyroxin which controls
the process of metamorphosis in them.
• The thyroxin only produces with the help of
iodine that is present in the water.
• lack of iodine in water the tadpoles would never
turn into adult frogs.

21. Have you noticed that frog produced sound in
rainy season? So, why do frogs make sound
during rainy?

22. QUESTION
• …..…..hormone is helpful in metamorphosis
of frog.

23. RECAPITULATION:
 Define chromosomes. And types.
 Determination of sex in human.
 Explain non- sex hormones present in human
body.
 Define metamorphosis.
 Which hormones present in insect & frog.