genetic pattern of inheritance genes and DNA PROTEIN SYNTHESIS

1.  Contents
 Genetic chromosomes
 Genes and DNA
 Protein synthesis
 Genetic pattern of inheritance

2. Genetic Chromosomes
 Genes are contained in
chromosomes, which are mainly in
the cell nucleus. A chromosome
contains hundreds to thousands of
genes. Every human cell contains
23 pairs of chromosomes, for a total
of 46 chromosomes. A trait is any
gene-determined characteristic and
is often determined by more than
one gene.

3.  Chromosomes are not visible in the cell’s nucleus—not even
under a microscope—when the cell is not dividing. However,
the DNA that makes up chromosomes becomes more tightly
packed during cell division and is then visible under a
microscope. Most of what researchers know about
chromosomes was learned by observing chromosomes
during cell division.
 Each chromosome has a constriction point called the
centromere, which divides the chromosome into two
sections, or “arms.” The short arm of the chromosome is
labeled the “p arm.” The long arm of the chromosome is
labeled the “q arm.” The location of the centromere on each
chromosome gives the chromosome its characteristic shape,
and can be used to help describe the location of specific
genes

4.  Genes & DNA
 A gene is the basic physical and functional unit of heredity.
Genes are made up of DNA. Some genes act as instruction
to make molecules called proteins. However, many genes
do not code for proteins. In humans, genes vary in size
from a few hundred DNA bases to more than 2 million
bases. The Human Genome Project estimated that
humans have between 20,000 and 25,000 genes.
 Every person has two copies of each gene, one inherited
from each parent. Most genes are the same in all people,
but a small number of genes (less than 1 percent of the
total) are slightly different between people. Alleles are
forms of the same gene with small differences in their
sequence of DNA bases. These small differences
contribute to each person’s unique physical features

6.  Protein Synthesis
 Protein synthesis is one of the most
fundamental biological processes by which
individual cells build their specific proteins.
Within the process are involved both DNA
(deoxyribonucleic acid) and different in their
function ribonucleic acids (RNA). The process
is initiated in the cell’s nucleus, where specific
enzymes unwind the needed section of DNA,
which makes the DNA in this region accessible
and a RNA copy can be made. This RNA
molecule then moves from the nucleus to the
cell cytoplasm, where the actual the process of
protein synthesis take place

7. PROTEIN
SYNTHESIS

8. Genetic pattern of inheritance
 It is important to understand the basic laws of inheritance to
appreciate how conditions are passed on in a family. An accurate
family health history is a valuable tool to illustrate how conditions
are passed down through generations.
For some conditions, family members with the same mutation may
not have the same symptoms. For other conditions, individuals with
different mutations can have similar characteristics. This is because
gene expression is influenced by genes, as well as by the
environment. Diseases caused by mutations in a single gene are
usually inherited in a simple pattern, depending on the location of
the gene and whether one or two normal copies of the gene are
needed. This is often referred to as Mendelian inheitance bacause
Gregor Mendel first observed these patterns in a garden pea plants.
Most single gene disorders are rare; but, in total, they affect millions
of people in the united states.

9.  Several basic models of inheritance exist for single gene disorders:
autosomal dominant, autosomal recessive, X- linked dominant, X-
linked recessive. However, not all genetic conditions will follow
these patterns, and other rare forms of inheritance such as
mitochondrial inheritance exist.
 Dominant mutations are expressed when only one copy of that
mutation is present. Therefore, anyone who inherits one dominant
disease mutation such as the mutation for Huntington’s disease will
have that disease. Dominantly inherited genetic disease tend to
occur in every generation of a family. Each affected person usually
has one affected parent. However, dominant mutations can also
happen in an individual for the first time, with no family history of the
condition.
 Recessive mutations require two mutated copies for diseases to
develop. Recessive genetic diseases are typically not seen in every
generation of an affected family. The parents of an affected person
are generally carriers; unaffected people who have a copy of a
mutated gene. If both parents are carriers of the same mutated
gene and both pass it to the child, the child will be affected.

11. Thank you…