CHAPTER 3: HEREDITY AND VARIATION
Subtopic: Cell division
By the end of the lesson, you should be able to:i. State what are genes, deoxyribonucleic
acid (DNA) and chromosomesii. Describe the relationship between gene,
DNA and chromosome.
CELL DIVISION
Human built up of billions of cells
Growth involve continuous cell division which are controlled by genetic material in the nucleus
Cell
Nucleus
Chromosome
Nucleus control the activities in the cell
The long fine thread-like structure in the nucleus
are called chromosome
Chromosomes provide all the information for
living organism to function and genetics
information for living organism to grow and live.
chromosome
Deoxyribonucleic acid (DNA)
Chromosome are made up of deoxyribonucleic acid
(DNA)
The DNA is a large organic molecule with two
strands, twisted into a spiral staircase formation
called a double helix
DNA carries genetic instruction which the cell need
to carry out its activities
Genes are pieces of DNA
They are arrange along the length
of the chromosomes They are hereditary materials
which are responsible to producing characteristics of the organism
DNAGene
RELATIOSHIP BETWEEN THEM
Control activity of
Carry genetic instruction
responsible to producing characteristics
Provide genetic to function, to grow and live.
Gene
chromosome
Nucleus
Deoxyribonucleic acid (DNA)
Cell
