The cells in our bodies contain chromosomes which contains a long molecule of DNA. Each DNA molecule contains many genes. A gene is a segment of a DNA molecule that gives the instructions for making a protein.

1. By Prof. Liwayway Memije-Cruz

2. How genesin thechromosomescan
influenceone’scharacteristics?

3. Thecellsin our bodiescontain chromosomes.
Each chromosomecontainsalong molecule
of DNA.
Each DNA moleculecontainsmany genes.
 A geneisasegment of aDNA moleculethat
givestheinstructionsin making proteins.
Genesaresectionsof chromosomesthat have
coded instructionsfor making proteins.

5.  different
versionsof the
samegene
 givethe
instructionsfor
making
different
versionsof
protein

6.  Chromosomescomein pairs
of homologouschromosomes.
In each pair of homologous
chromosomes, both
chromosomeshavethesame
genesat thesamelocations.
 A genemay havedifferent
alleleson thetwo homologous
chromosomes. (e.g. Aa) or a
genemay havethesame
alleles(e.g. SS).

7. Genotype Protein Phenotype(characteristics)
AA or Aa Enough normal enzymeto make
melanin in skin and hair
Normal skin and hair color
aa Defectiveenzymefor melanin
production
Very paleskin and hair color;
albino
SSor Ss Enough normal hemoglobin to
prevent sicklecell anemia
Normal blood; no sicklecell
anemia
ss Sicklecell hemoglobin, which
can causered blood cellsto
becomesickleshaped
Sickleshaped red blood cells
can block blood flow in the
smallest blood vessels, causing
pain, etc.; sicklecell anemia

8. Many of thegeneson each chromosome
givetheinstructionsfor making thelarge
number of proteinsthat areneeded for
normal cell structureand function.
Each cell needsto haveacompleteset of
chromosomeswith all of thesegenes.

9.  http://serendip.brynmawr.edu/exchange/waldron/mitosis
 http://serendip.brynmawr.edu/exchange/waldron/mitosismeiosis

10.  http://serendip.brynmawr.edu/exchange/waldron/mitosis
 http://serendip.brynmawr.edu/exchange/waldron/mitosismeiosis