Ch 8_Cell Reproduction_1.pdf
Transcript of Ch 8_Cell Reproduction_1.pdf
• VISHAL SAXENA
• Faculty, Dept. of Biological Sciences,
• Chamber No. : 3222-G
• Chamber consultation hours:
– T, Th – 3:00 – 5:00 PM
– Contact No.: 9414069231
CHAMBER CONSULTATION HOURS
Instructor Day Time Room No.
Panchsheela Nogia
Tuesday 5PM- 6PM 3228
Divya Nivedita Friday 5PM- 6PM 3167
Jyothi Nagraj Saturday 3:00PM- 4PM 3132
Parva Sharma Thursday 5PM- 6PM 3167
Chetna Sangwan Thursday 5:15 PM-6:15PM 3228
Vidushi Asati Friday 5PM- 6PM 3228
Sachi Monday 10AM- 12Noon 3226
Chamber Consultation Hour for Instructor In – charge: Dr. Shilpi Garg: Thursday and Friday : 5:00PM- 6:00PM
Average Life Span
• Normal human being – Approx. 70 years
• Muscle Cells – About 15 years
• Skin cells – 10 days on avg.
• Red Blood Cells – ~ 90 – 120 days
• Neutrophils – Few hours
What controls these life processes?
• Cell is the basic structural and functional unit of living organism
• A new cell arises from a pre-existing cell
• The different activities taking place within a cell/s, help them
– Categories/ Differentiate into Types
– Differentiate b/w Living and dead cells
– Form tissues/ organs with specific functions
– REPRODUCE
Life Processes of a Cell
Mitotic
(M) phase:
cell division
(10% of time)
G2
Growth A cell cycle is the ordered sequence of events that extend from the time a cell is first formed from a dividing parent cell to its own division into two cells.
Interphase: metabolism and growth (90% of time)
The Cell Cycle
• Most of the cell cycle is spent in interphase, which lasts for at least 90% of the cell cycle.
• During interphase, a cell
– performs its normal functions,
– doubles everything in its cytoplasm, and
– grows in size.
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Interphase
• Different Phases include
– G1 and G2 = Growth/ Gap phases
– During G1, each chromosome is single, and the cell
performs its normal functions.
– S Phase = the DNA in the nucleus is precisely doubled.
– During G2 (after DNA duplication during the S phase),
each chromosome in the cell consists of two identical
sister chromatids, and the cell prepares to divide.
Cell reproduction phase
• Cell divides to form two daughter cells
• Each new cell carries one copy of DNA from original cell
• Division can be of different types
– Asexual Reproduction
• Binary fission
• Mitosis
– growth and maintenance of multi-cellular organisms
– Sexual Reproduction – Meiosis
– For introducing variations
• Includes two overlapping processes:
1. Mitosis, in which the nucleus and its contents divide evenly into two daughter nuclei, and
2. Cytokinesis, in which the cytoplasm (along with all the organelles) is divided in two.
• The combination of mitosis and cytokinesis produces two genetically identical daughter cells.
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Mitotic (M) phase
Mitosis
• Mitosis consists of four distinct phases:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
© 2016 Pearson Education, Inc.