Question

this question has two parts. use the information to answer part a and part b. patricia lives near a small island. a population of tortoises lives on the island with no predators. some of the tortoises have long necks (l) and some of the tortoises have short necks (s). patricia wants to know how the numbers of long - necked and short - necked tortoises will change over time. she collects some information.

• all female long - necked tortoises are able to lay eggs.
• only half of female short - necked tortoises are able to lay eggs.
• in year 1 of the study, there are twice as many short - necked tortoises as long - necked tortoises (s = 2l).

part a
patricia predicts the conditions on the island will stay the same.
what equation will most likely describe the tortoise population in year 2?
a. s = l
b. s = 2l
c. s = 4l
part b
what statement about the tortoise population does the correct answer from part a best support?
a. the numbers of long - necked and short - necked tortoises are stable.
b. there will always be fewer long - necked tortoises than short - necked tortoises.
c. the long - necked tortoises have a survival advantage over the short - necked tortoises.

Explanation:

Step1: Analyze reproduction rates

All female long - necked tortoises lay eggs, while only half of female short - necked tortoises lay eggs. Initially $S = 2L$. Let the number of long - necked tortoises that reproduce be $x$ (assuming all females reproduce), and the number of short - necked tortoises that reproduce be $y$. If the initial number of long - necked tortoises is $L$ and short - necked is $S = 2L$, then the number of reproducing short - necked tortoises is $y=\frac{1}{2}S = L$ (since $S = 2L$), which is the same as the number of long - necked tortoises that reproduce.

Step2: Determine population equation

Over time, with the same reproduction rate for the two types (in terms of the number of reproducing individuals), the population of long - necked ($L$) and short - necked ($S$) tortoises will become equal. So the equation for the tortoise population in year 2 is $S = L$.

Answer:

Part A: A. $S = L$
Part B: A. The numbers of long - necked and short - necked tortoises are stable.