GENETICS
GENETICS
BRAINSTORM
Genetic technology is changing at a
rapid rate. Soon humans will have
enough knowledge and technology to
modify humans.
The question is should we?
GENETICS
The field of biology that involves the study of how
genetic material is passed from one generation of
organisms or cells to the next generation
All cells come from pre-existing cells, therefore, the
continuity of life is dependent on the process of
REPRODUCTION
Stages of the Cell Cycle
First Major Stage
Interphase:
Cell grows, develops into a mature, functioning cell,
copies it’s DNA and prepares for cell division.
3 phases:G1 (Growth 1),S (Synthesis) and G2
(Growth 2)
G1 = major growth period and synthesizing of
molecules
S = DNA (chromatin) is copied or replicated. The
replicated chromatin coils up and forms double
stranded chromosomes
G2 = continued growth and preparation for Mitosis
MITOSIS
Let’s draw the key player of mitosis:
coiled chromatin
centromere
chromosome
2 strands of coiled
chromatin =
sister chromatids
Let’s review the 4 stages of Mitosis
Structures of Genetic
Material
DNA is made up of two long strands that form a
spiral shape called a double helix
Most of the cell cycle, DNA exists as strands of
chromatin fibre.
Once mitosis begins, the chromatin condenses into
distinct chromosomes
Structures of Genetic
Material
•The basic unit of the DNA molecule is called a
nucleotide
•Each nucleotide consists of 1. phosphate group
2. sugar group
4 Types
A-T
3. nitrogenous
base
C-G
Complimentary
Base
Pairing
Paired Chromosomes
Human somatic cells have 46 chromosomes ( 23
pairs)
For each pair, one chromosome is from the mother,
and the other is from the father
One pair = sex chromosomes ( X and Y)
XX = female, XY = male
All other pairs = autosomes
Homologous Pair
KARYOTYPE: set of chromosomes that
an individual has
Homologous
Chromosomes
Are chromosomes that contain the same sequence
of genes as another chromosome
Genes = are sections of DNA that contain genetic
information for the inheritance of specific traits
Homologous chromosomes carry genes for the same
traits, such as hair colour, at the same location
• Each chromosome carries different forms of the
same gene called ALLELES
• This difference accounts for the differences in
specific traits, such as blue eyes versus brown eyes
Homework
Pg. 168 # 5, 9, 12, 13, 17