2. Objectives:
To distinguish between
chromatin and chromosome
To define homologous
chromosomes
To distinguish between
diploid and haploid
3. Chromatin found in the
nucleus of a nondividing cell
made of DNA and protein
4.
5.
6.
7. DNA in chromatin replicates
before cell division
Chromatin becomes highly
coiled and condensed
Becomes visible as
a chromosome
8. A Chromosome consists
of 2 identical chromatids
Centromere – point at which each
pair of chromatids is attached
centromere
9.
10.
11. Homologous Chromosomes
pair of chromosomes that
have same size and shape
found in
sexually
reproducing
organisms
human body
cells have
23 homologous
pairs
12.
13. Diploid (2N) – cell that contains
both chromosomes
of a homologous pair
human body
cells 46
14. Haploid # (N) – cell that has
only one
chromosome
of each
homologous
pair
egg &
sperm
human sex
cells 23
15.
16. Objectives:
To describe the cell cycle
To define mitosis
To list and describe the
stages of mitosis
17. Cell Cycle – period from
beginning of one mitosis
to beginning of next
Cell cycle consists of three stages:
I. Interphase
II. Mitosis
III. Cytokinesis
22. Mitosis – division of
the cell nucleus
number of chromosomes
remains the same
occurs in body cells and unicellular
organisms
produces identical daughter
cells
53. cell that results from
the fusion of gametes
forms when
sperm
fertilizes
the egg
Zygote
54. process that results in genes
being combined in new ways
during meiosis
introduces variation between
parents and offspring
gives survival advantage to
sexually reproducing
organisms
Genetic Recombination
55.
56.
57. Objectives:
To define cancer
To describe the role
of gene expression in
cancer
To describe the
causes of cancer
60. Tumor – abnormal proliferation of
cells that results from uncontrolled,
abnormal cell division
Types of Tumors
benign – cells remain within a
mass and do not spread
malignant – cells may invade and
destroy healthy tissues elsewhere
in the body
61.
62. spread of cancer cells beyond the
original site of growth
cells grow as malignant
tumor in epithelium
Metastasis
63.
64. Types of Genes Implicated in
Cancer Development
1. Oncogenes
2. Tumor-Suppressor
Genes
3. DNA Repair Genes
65. proto-oncogene –
a gene which
regulates normal
cell growth
Oncogene – mutated proto-
oncogene that can cause
uncontrolled cell growth
and proliferation
66.
67. inhibits cell division and
prevents tumor formation
Tumor-Suppressor Gene
mutations in tumor
suppressor genes
promote cell division
and allow genetically
damaged cells to
grow out of control
68. repairs mutations in cellular
DNA before a cell enters
mitosis
• mutations in repair
genes leads to
continued transcription
of mutated DNA
sequences and affects
normal cell functioning
DNA Repair Gene