sex determination in humans seminar presentation

1. SAHYADRI SCIENCE COLLEGE.
(KUVEMPU UNIVERSITY)
SEMINAR PRESENTATION ON SEX
DETERMINATION IN HUMANS.
TO:
Dr. C.K. RAMESH SIR
PROFESSER
Dept. BIOTECHNOLOGY
SAHYADRI SCIENCE COLLEGE
SHIVMOGGA
BY:
TRUPTHI.A
1ST MSc. BIOTECHNOLOGY
SAHYADRI SCIENCE COLLEGE
SHIVMOGGA

2. CONTENTS
SL.N
O
TITLE
01
INTRODUCTION
02
SEX CHROMOSOMES
03
DIFFERENCES BETWEEN X AND Y CHROMOSOME
04
STRUCTURE OF Y CHROMOSOME
05
THE XX-XY TYPE TO SEX DETERMINATION
06
CHROMOSOMAL DISORDERS AND DIAGNOSIS
07
SUMMARY
08
CONCLUSION
09
REFERENCE

3. INTRODUCTION
• The method by which distinction
between male and female is
established in an organism under
genetic control.
• The sex chromosomes are
responsible for determination of
separate sexes.
• It is a biological system that
determines the development of
sexual characteristics in an
organism.
• Edmund Wilson and Nettie Stevens
discovered sex determination
system in1903.

4. SEX CHROMOSOMES

5. DIFFERENCE BETWEEN X AND Y
CHROMOSOME.
BASIC TERMS X- CHROMOSOME Y-CHROMOSOME
MEANING It is a sex chromosome
that occurs in pair among
female cells and single in
male cell.
It is a sex chromosome
which is present in male
cells.
SEX DETERMINATION Contain genes that
determine female gender.
Contain genes that
determine male gender.
SIZE AND NUMBER Tend to be bigger and
about 155 million base
pairs.
Tend to be smaller and
about 59 million base pair.
REPRESENT 5 percent of the human
genome.
2 percent of the human
genome.
NUMBER OF GENES About 100 genes About 70 genes.
GENOTYPE Female genotype Male genotype
SRY GENE SRY gene is absent SRY gene is present for
testes development.

6. STRUCTURE OF Y-CHROMOSOME.

7. The XX-XY type
of
chromosomal
sex
determinations:

8. CHROMOSOMAL DISORDERS:
KLINEFELTER SYNDROME:

9. KLINEFELTER
SYNDROME
• It is a genetic condition in
which a boy is born with an
extra X chromosome. Instead
of typical XY chromosome in
men, they will have XXY, so
this condition is sometimes
called XXY syndrome.
• In 1942,Dr Harry Klinefelter
and his coworkers first
described the combination of
features that has come to be
recognized as Klinefelter
syndrome.

10. TURNER’S SYNDROME

11. TURNER
SYNDROME
• A chromosomal disorder in
which a female is born with
only one X chromosome.
• In 1938, Dr Henry Turner
first discovered turner
syndrome while studying 7
girls who all had the same
unusual developmental and
physical features.

12. TRUEHERMAPRODITISM
• It is a condition where an individual has both
ovarian and testicular tissue. In 46 XY
individuals have ambiguous or female external
genitalia but the chromosomal constitution
and reproductive organs of a male, though the
testis may be malformed or absent.

13. KARYOTYPING
Karyotyping is the
process of pairing and
ordering all the
chromosomes of an
organism, thus
providing a genome-
wide snapshot of an
individual's
chromosomes.

14. BARR BODY DETECTION

15. • It was discovered by MURRAY BARR in the
year 1948.
• It is an inactive X chromosome in a cell with
more than one X chromosome.
• It is carried out by taking buccal mucosal cells
and could be observed only in females.

16. AMINOCENTESIS
It is a medical procedure
used primarily in prenatal
diagnosis of chromosomal
abnormalities and fetal
infections as well as for
sex determination.

17. • In this procedure a small amount of amniotic
fluid, which contains fetal tissues, is sampled
from the amniotic sac surrounding a developing
fetus.
• Doctors Jens Bang and Allen Northeved from
Denmark were the first to report amniocentesis
done with the guide of an ultrasound in 1972.
• It is performed when a women is between 15 to
20 week of gestation.

18. CHORIONIC VILLUS SAMPLING(CVS)
• It is a form of prenatal
diagnosis to determine
chromosomal or genetic
disorders in the fetus.
• It includes the sampling of
the chorionic villus and
testing it fir chromosomal
abnormalities usually FISH
or PCR.
• It is done during 9th to 13th
weeks of pregnancy.
• It was discovered by Italian
biologist Giuseppe Simoni in
1983.

19. CONCLUSION
Researcher’s have studied the process of sex determination in a wide range of
species and discovered several mechanism of sex determination and conclude
that the difference in chromosome constitution is a mechanism for
determining sex at the time of fertilization.

20. REFERENCE
• Dr. Ajoy Paul, (2011),Textbook
of genetics, Books and Allied
private limited, Kolkata. P:932-
936.
• Silverthorne, Dee, U(2010),
Reproduction and
Development. In: Human
Physiology: an integrated
approach. 5th ed, san
Francisco: Pearson education.
p:828-831
• https://en.wikipedia.org/wiki/S
exual_differentiation_in_huma
ns

21. THANKYOU