Look at the following image of parts of a whale. In humans, the pelvis and femur, or thigh bone, are involved in walking. What is true of the pelvis and femur in living whales.
1 point
They are examples of fossils.
They are vestigial structures.
They are acquired traits.
They are examples of natural variation.
They are vestigial structures.
In living whales, the pelvis and femur are vestigial structures.
To determine the correct answer, let's analyze each option and understand its meaning in the context of living whales.
1. They are examples of fossils: Fossils are the remains or traces of organisms preserved in rocks or sediments over time. This option is incorrect because living whales are not fossils; they are living organisms.
2. They are vestigial structures: Vestigial structures are anatomical features that have lost their original function in a species through evolution. In the case of living whales, the pelvis and femur have become reduced in size and are not involved in supporting the hind limbs or walking. Instead, they are remnants of their terrestrial ancestors. This option is correct as the pelvis and femur in whales are considered vestigial structures.
3. They are acquired traits: Acquired traits are characteristics that an organism develops during its lifetime as a result of environmental or behavioral influences. The pelvis and femur in whales are not acquired traits, as they are not developed or modified during the whale's lifetime. They are inherited features from their evolutionary ancestors.
4. They are examples of natural variation: Natural variation refers to the range of differences within a population resulting from genetic diversity. The presence or absence of a pelvis and femur in whales is not an example of natural variation since all living whales exhibit a reduction or absence of these structures. Therefore, this option is incorrect.
In conclusion, the correct answer is: "They are vestigial structures."