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Biology: Genetics, Reproduction, and Biotechnology - Applications and Ethics of Biotechnology

Grade 8IB

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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Biotechnology involves the manipulation of living organisms or their components to produce useful products. In Grade 8, this focuses on genetic engineering, which is the direct manipulation of an organism's genes using biotechnology, such as inserting a gene from one species into another to create a Genetically Modified Organism (GMO).

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Recombinant DNA technology is a key application where a specific gene (e.g., the gene for human insulin) is inserted into a bacterial plasmidplasmid. This transformed bacterium then acts as a biological factory to mass-produce the protein.

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DNA Profiling, or DNA fingerprinting, utilizes unique patterns in non-coding regions of DNA. This is used in forensics to match crime scene evidence with a suspect's DNA, where the probability of a random match is often less than 11 in 1×1091 \times 10^{9}.

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Cloning is the process of producing genetically identical individuals. Somatic Cell Nuclear Transfer (SCNT) involves removing the nucleus of an egg cell and replacing it with the nucleus of a somatic (body) cell from the donor.

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Ethical considerations are central to IB Science. These include the 'Pros' (increased crop yield, reduced pesticide use, curing genetic diseases) and 'Cons' (long-term health unknowns, ecological disruption through cross-pollination, and moral concerns regarding 'designer babies').

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Stem cell research involves using undifferentiated cells that have the potential to develop into various cell types. Ethical debates often center on the source of these cells, particularly embryonic stem cells.

📐Formulae

Probability of Genotype=Number of favorable outcomesTotal number of possible outcomes\text{Probability of Genotype} = \frac{\text{Number of favorable outcomes}}{\text{Total number of possible outcomes}}

Growth of Bacteria (n generations)=N0×2n\text{Growth of Bacteria (n generations)} = N_0 \times 2^n

Base Pairing Rule: [A]=[T] and [G]=[C]\text{Base Pairing Rule: } [A] = [T] \text{ and } [G] = [C]

💡Examples

Problem 1:

In a lab, a scientist is using bacteria to produce a growth hormone. If the bacteria population starts with 100100 cells and doubles every 3030 minutes, calculate the population after 22 hours.

Solution:

n=120 minutes30 minutes=4 generationsn = \frac{120 \text{ minutes}}{30 \text{ minutes}} = 4 \text{ generations} N=100×24N = 100 \times 2^4 N=100×16=1600N = 100 \times 16 = 1600

Explanation:

The population growth of modified bacteria follows an exponential pattern. After 22 hours (44 doubling periods), the initial 100100 cells result in 16001600 cells.

Problem 2:

A forensic scientist finds that a DNA sample from a crime scene has a 0.050.05 probability of matching Segment A and a 0.020.02 probability of matching Segment B in the general population. What is the probability that a person matches both segments by pure chance?

Solution:

P(A and B)=P(A)×P(B)P(A \text{ and } B) = P(A) \times P(B) P=0.05×0.02=0.001P = 0.05 \times 0.02 = 0.001

Explanation:

To find the probability of two independent genetic markers matching simultaneously, we multiply their individual probabilities. A 0.0010.001 (or 0.1%0.1\%) chance indicates a relatively high degree of certainty for identification, though forensic standards usually require much lower probabilities.