FREE RADICALS & ANTIOXIDANTS 🟡 BIOCHEMISTRY

 Free radicals are unstable molecules that can cause damage to cells, proteins, and DNA within the body, contributing to aging and various diseases. They are naturally formed during metabolism but can also be generated by external factors like pollution and radiation. 

Antioxidants, on the other hand, are compounds that neutralize free radicals by donating an electron, thereby preventing or reducing the damage they inflict. Found abundantly in fruits, vegetables, and other plant-based foods, antioxidants play a crucial role in maintaining cellular health and protecting the body from oxidative stress.

here is an overview

🟡 Differences between Free Radicals & Antioxidants

Biochemical Analysis of Protein Carbohydrate & Lipid

 The chemical analysis of General Biochemical tests of ✔️Carbohydrate,✔️ Protein & ✔️ Fat :

Aquaculture MCQ SEMESTER 2 (ZOOM & MDC)

Syllabus followed [University of Calcutta]

SEC2-AQUACULTURE MCQ MOCK PRACTICE SETS BY (S.M.E.)

• UNIT- I:https://drive.google.com/file/d/1nWOipCWAAa33vuBVfnlGBCE1xHOS0xGa/view?usp=sharing

• UNIT-II: PARTI-https://drive.google.com/file/d/1dFHGjp5qMY6N3Q8IV9mAQ4lY4YDPuK4q/view?usp=sharing
• UNIT-II:PART-II https://drive.google.com/file/d/1KtN6TvE3EE2qFvADc4TseWdpRrXEFjY7/view?usp=sharing
  

• UNIT-III:https://drive.google.com/file/d/1vQAk5e-iW0YaSMt7exHjDiVIRv5-EhlN/view?usp=sharing

• UNIT-IV: https://drive.google.com/file/d/1Wz-DOFljRH6DMl4_fEf4pdPwqsA6XOU2/view?usp=sharing

• UNIT-V: https://drive.google.com/file/d/1myHfFY1Vplj5ofAG547AgHIUgfngM591/view?usp=sharing

• Solution:(Solutions will be provided by mail upon request.)

Study of life table and survivorship curve from a hypothetical data sets (ZOOLOGY_MDC)

1.  Following is the table of age specific birthrates for gray squirrel population, construct  life table & survivorship curve. comment on the survivorship curve.

X (Age in years)	0	1	2	3	4	5	6
nx	1000	300	150	90	40	10	0

Solution: https://drive.google.com/file/d/1BvZmaECReWtdok3NiF2zP_fJeXD9D35F/view?usp=sharing

2. Following is the table of a hypothetical data set, construct the life table & survivorship curve. Comment ion the survivorship curve.

X	1	2	3	4	5	6	7	8	9	10
nx	1000	970	940	900	870	830	750	640	480	0

Solution: https://drive.google.com/file/d/1Bbt2Nmn5FEZw8kX5GtDF9opNdi2lSAD/view?usp=sharing

3. Following is the table of a hypothetical data set, construct the life table & survivorship curve. Comment ion the survivorship curve.

X	1	2	3	4	5	6	7	8	9	10
nx	1000	850	740	650	550	450	350	245	150	0

Solution: https://drive.google.com/file/d/1YlVTTQUfu5HHleekgZiloiacXi3i5Bp/view?usp=sharing

4.Following is the table of a hypothetical data set, construct the life table & survivorship curve. Comment ion the survivorship curve.

X	1	2	3	4	5	6	7	8	9	10
nx	1000	920	790	510	465	450	250	215	135	0

Solution: Do it yourself

5. Following is the table of a hypothetical data set, construct the life table & survivorship curve on a (log ₁₀) scale. Comment ion the survivorship curve.

X (Age group in Years)	0-5	6-10	11-15	16-20	21-25	26-30	31-35	36-40	41-45	46-50
nx	4600	4000	2500	2100	1800	1300	1000	855	435	0

Solution:  https://drive.google.com/file/d/1WruobGTu64Rw7Ep_bB3NHfX1xCL9cqqS/view?usp=sharing

Study of life table and survivorship curve from a hypothetical data set SET-III

💹SET-I: https://biomassfootprints.blogspot.com/2025/07/study-of-life-table-and-survivorship.html

💹SET-II :https://biomassfootprints.blogspot.com/2025/07/study-of-life-table-and-survivorship_18.html

💹SET-III

Life table of a Darwin finch, Galapagos cactus finch (Geospiza sp) is given below-

X	0	1	2	3	4	5	6
nx	1000	980	920	800	750	620	550

🔷Calculation:

X	nx	lx	dx	qx	Lx	Tx	ex
Age in Year	Observed number alive	nx / n0	nx - n(x+1)	dx / nx	[nx+ n(x+1)]/2	∑ Lx	Tx / nx
0	1000	1	1000-980 =20	20/1000 =0.02	[1000+980]/2 =990	990+950+860+ 775+685+585+275 =5,120	5.12
1	980	0.98	980-920 =60	0.061	950	950+860+ 775+685+585+275 =4130	4.21
2	920	0.92	120	0.130	860	860+ 775+685+585+275 =3180	3.45
3	800	0.8	50	0.06	775	775+685+585+275 =2320	2.9
4	750	0.75	130	0.17	685	685+585+275 =1545	2.06
5	620	0.62	70	0.112	585	585+275=860	1.38
6	550	0.55	550	1.0	275	275	0.5

 

🔷Conclusion:

1. More or less constant death throughout life. Individuals have approximately constant chance of surviving throughout the life span. 
2. Life expectancy also changes with age.

🔷Comment: Expectation of life declines with age. This life table parameters reflects low-level of environmental uncertainty & their survival strategies in their native environment.

🔷Plotting & study of Survivorship curve from a hypothetical data set:

X	0	1	2	3	4	5	6
nx	1000	980	920	800	750	620	550
log nx	3	3	2.96	2.90	2.87	2.79	2.74

🔷Survivorship curve on log scale: 

On a graph paper nx (log 10 scale) is plotted against time interval (X) & following  graph is obtained.

                                         

🔷Conclusion: This diagonal survivorship curve of a Geospiza sp population concluded that individuals have an approximately constant chance of survival throughout the life span, because the rate of death is more or less constant.

🔷Survivorship curve on arithmetic scale: On a graph paper nx is plotted against time interval (X) & following graph is obtained.

🔷Observation: The survivorship curve shows 'convex' type (Type-I). 

🔷Conclusion: Here, Population mortality is low during initial stage, then  increasing throughout the life span.