• 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

Mathematics/ Physics •Multiplication

•Division

Life Processes

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Life Processes

• Birth

• Growth

• Death

Replicate/ Multiply/ Reproduce

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

Mechanisms & Processes of Cellular Reproduction

Cell Cycle and Cell Division

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.

G1

G2

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

What Cell Reproduction Accomplishes

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Sea Urchin

© 2016 Pearson Education, Inc. Video (time lapse)

• 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

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Prophase

• DNA coils and condenses to form chromatids and chromosomes

• Nuclear envelope starts disappearing

• Centrioles move to different poles

• Mitotic spindles start forming from the centrioles