Gregor Mendel's work determined that hereditary traits are transmitted from parents to offspring through discrete units now known as genes. DNA controls all chemical processes in cells and determines characteristics like eye color or type of organism. DNA is a long molecule made of nucleotides, which each contain a sugar, phosphate, and organic base. The sequence of bases in a gene contains instructions for building proteins.

2.  The study of genes and the inheritance of
traits
 Gregor Mendel’s work determined that
hereditary characters are transmitted to
offspring by separate units
 Later known to be genes

3.  These are features
you exhibit
physically
( your looks)
Example: Eye color -
green

4.  The different
versions of a
characteristic
 Example: blue,
green, and brown
eyes

5.  Occurs when traits
are passed down
from parent to
child.

6. Most human cells
contain 46 chromosomes:
 2 sex chromosomes (X,Y):
XY – in males.
XX – in females.
 22 pairs of chromosomes
named autosomes.
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7. 1

8. DNA stands for deoxyribose nucleic acid
This chemical substance is present in the nucleus
of all cells in all living organisms
DNA controls all the chemical changes which
take place in cells
The kind of cell which is formed, (muscle, blood,
nerve etc) is controlled by DNA
The kind of organism which is produced (buttercup,
giraffe, herring, human etc) is controlled by DNA
2

9. DNA is a very large molecule made up of a long
chain of sub-units
The sub-units are called nucleotides
Each nucleotide is made up of
a sugar called deoxyribose
a phosphate group -PO4 and
an organic base
3

10. Ribose is a sugar, like glucose, but with only five
carbon atoms in its molecule
Deoxyribose is almost the same but lacks one
oxygen atom
Both molecules may be represented by the symbol
4

11. The most common organic bases are
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
5

12. The deoxyribose, the phosphate and one of the bases
adenine
deoxyribose
PO4
Combine to form a nucleotide
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13. A molecule of DNA is
formed by millions of
nucleotides joined
together in a long chain
PO4
PO4
PO4
PO4
sugar-phosphate
backbone
+ bases
7

14. In fact, the DNA usually consists of a double
strand of nucleotides
The sugar-phosphate chains are on the outside
and the strands are held together by chemical
bonds between the bases
8

15. PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
9

16. Nitrogenous
Base (A,T,G or C)
“Rungs of ladder”
“Legs of ladder”
Phosphate &
Sugar Backbone

17.  Bits of information
passed down from
parent to child.
 Made of chemicals
called DNA.

18. How DNA
works
National Human Genome
Research Institute - NIH

20. The sequence of bases in a gene is a code
instructing the cell how to construct a
particular protein – i.e. the number of amino
acids and the order in which they are to be
assembled.
His
Met
Phe
His
Glu
Pro
Cys
Cys
MAGlu K

22.  Recombinant DNA technology
 PCR
 Botting technique
Southern Blotting
Western Blotting
Northern Blotting

24.  Synthesis of hormones
 Laboratory diagnosis
 Gene therapy
 Use in forensic medicine

25.  Trisomy 21
 Turners syndrome
 Klinefelters syndrome
 X-linked disorders

26.  Point mutation
 Frame shift mutation

27.  Oncogenes (RET proto-oncogene)
 Tumor suppressor genes ( p53 , RB gene)
 Telomerase

28.  Apoptosis is also called as programmed cell
death
 Controlled by cell’s genes
 Cell suicide
 Different from necrosis
 No inflammation
 Physiological process


29.  Apoptosis for proper development of tissues
 Apoptosis for normal functioning of body
 Apoptosis of cells that are a threat to
integrity of tissues

30.  Internal stimuli
 External stimuli
 Final common pathway

31.  DNA fragmentation
 Cytoplasm and chromatic condensation
 Membranous bleb formation
 Phagocytosis of debris