Cell Biology

Model answers, notes and strategy to deal with Cell Biology

How important is this chapter?

Cell biology is very important chapter of the syllabus of paper 2 of zoology. It accounts for nearly half of the section A of paper 2 and overall 25% of the paper.
The best things about this chapter are:
1. There is less to mug up as compared to chapters like biochemistry .
2. familiarity with the topics, because we are introduced to structure of cell in standard 6th itself.
3. Huge scope for diagrammatic representation and thus fetch  good marks.

Cell Biology-

Here I am dividing the syllabus in sub-parts, so that each part can be individually and easily dealt with.

Topics:

1.       Structure of cell

2.       Structure of cell and its organelles

(a)    Nucleus

(b)   Plasma membrane

(c)    Mitochondria

(d)   Golgi bodies

(e)   Endoplasmic reticulum

(f)     Lysosomes

(g)    Ribosomes

3.       Cell division

(a)    Mitosis

(b)   Meiosis

(c)    Mitotic spindle and mitotic apparatus

(d)   Chromosome movements

4.       Watson crick model of DNA

5.       DNA replication

6.       Protein synthesis

7.       Transcription and transcription factors

 What to study?

Syllabus is available online or can be downloaded from number of websites. But we actually need to decode the syllabus. That can be done by analyzing previous years question papers.

Last 5 years questions on cell biology:

2015

Q. Transport of small and large molecules across plasma membrane.

Q. Describe the ultra-structure of mitochondrion and explain why it is considered as a symbiotic cell organelle.

Q. What is transcription? Explain the initiation complex and the events leading to the formation of mRNA in eukaryotes.

2014

What is meant by C-Value paradox? Describe the ultrastructure of chromatin with emphasis on nucleosome and solenoid model of chromatin.

2013

Q. Describe the events that occurs in a cell during prophase and metaphase. Draw labelled diagrams-20marks

Q. Explain lysosomal disorders in human.

2012

Q. Distinguish co-transcriptional modifications from post-transcriptional modifications experimentally. Cite one example for each.- 10 marks

Q.what are introns and exons. How are introns different from spacer DNA?

Q. (i) What are initiation and termination codons?

     (ii) Which amino acid is specified by a single codon?

     (iii) Which amino acid is coded for by the termination codon?-4 marks (Note: this topic is overlapping with genetic code)

Q. Describe the mechanism of RNA splicing.

2011

Q. list the structural components of DNA and salient features of Watson and crick model of DNA structure. Explain how the structure ensures its self-replicability. -

Approach to this question-  marks 10 (3+5+2=10)- 100 words

Hence it can be divided as:

(a) 30 words: Structural Components 

(b) 50 words: Watson and Crick model

(c) 20 words- self replicability 

Here I am attaching the pdf of answer- sample answer- click here

Q. Give a diagrammatic representation of the organisation of ETC particles and components of oxidative phosphorylation on mitochondrial membrane. (15 marks)

Q. Discuss with examples how lysosomes are suicide bags of cells.

What can we conclude from it?

Structure of cell: (can be studied using any standard text book)- click here to download handwritten notes

what to study?

What is cell?

The cell theory.

Concepts like totipotency, differentiation, dedifferentiation, determination.

Difference between prokaryotic cell and eukaryotic cell.

Structure of cell organelles-

Click here to download handwritten notes

Cell division:

Click here to download my handwritten notes of chromosome movements

Mitosis and meosis ( Pg. 90-95 Griffith’s)

Central dogma of life:

Watson crick model of DNA (Chapter 7, pg 230 Griffith’s)

DNA replication (chapter 7, pg 241 Griffith’s)

Protein synthesis (chapter 9, pg 274 Griffith’s)

Transcription factors (chapter 8, pg 246 Griffith’s)

Note: we can see that half of the cell biology can be covered from just 3 chapters of Griffith’s. These topics can be completed from any other book also. It’s just that Griffith’s covers almost everything  and there is no need to study beyond that level.

Disclaimer: There is always a room for improvement so my answer or notes format doesn’t need to be strictly adhered to.

The books mentioned here can be downloaded for free from- click here

Please drop any queries regarding any particular question in the comment section.

All the best