Problem 9 - Biology: The Dynamic Science

Question

The degree of relatedness between a parent and its biological off spring: a. is the same as that between brother and sister. b. is less than that between brother and sister. c. depends on how many siblings the parent has. d. promotes an individual’s reproductive success. e. is the same as between fi rst cousins.

Step-by-Step Solution

Answer

The correct answer is option (a). The degree of relatedness between a parent and its biological offspring is the same as that between full brother and sister, because both are about 50% on average.

Step 1: Understanding Genetic Relationship

The degree of relatedness refers to the amount of genetic information or material that two individuals share. In terms of a parent and its biological offspring, they share 50% of their genes. This is because an offspring receives half of its genes from each parent.

Step 2: Comparing to Siblings

Siblings also share about 50% of their genes, assuming they are full siblings, having the same two parents. This is calculated on average, due to genetic recombination and segregation during meiosis. So, it can be said that the degree of relatedness between a parent and its biological offspring is roughly the same as that between full siblings. So option (a) is correct.

Step 3: Analysing Other Options

As for the other options, (b) is not correct because, as previously mentioned, siblings share about 50% of their genetic materials, not less. Option (c) is incorrect, as the number of siblings does not affect the degree of relatedness between a parent and its offspring. The correct understanding is that each sibling shares about 50% of their genetic materials with each of their parents, regardless of how many of them there are. Option (d) does not directly answer the question regarding degree of relatedness; although increasing an individual's reproductive success may possibly be a result of their genetic relatedness, it is not an answer to this specific question. Finally, (e) is not correct as the relatedness between first cousins is about 12.5%, significantly less than the 50% relatedness between a parent and offspring or between siblings.