Reptiles are ectotherms and cannot raise their body temperature above that of the environment.
Answer:
GM is a technology that involves inserting DNA into the genome of an organism. To produce a GM plant, new DNA is transferred into plant cells. Usually, the cells are then grown in tissue culture where they develop into plants. The seeds produced by these plants will inherit the new DNA.
Explanation:
The correct answer is "increased activity of the right hippocampal formation".
Hippocampus is a brain area which is part of the limbic system and is located below the cerebral cortex. Humans have two hippocampi, one in each side of the brain. Hippocampus is responsible for the formation of long-term memories, by participating in the consolidation of short-term to long-term memory. It also plays a very important role in spatial memory and orientation.
The task that this experienced cab-driver is asked to perform is related to spatial navigation and orientation abilities. The right hippocampus has been shown to participate in the formation of memory for locations in specific environments, while the left hippocampus has been shown to be involved in autobiographical and episodic memory. As a result, the PET scan will show an increased activity of the right hippocampus.
There are all sorts of ways to reconstruct the history of life on Earth. Pinning down when specific events occurred is often tricky, though. For this, biologists depend mainly on dating the rocks in which fossils are found, and by looking at the “molecular clocks” in the DNA of living organisms.
There are problems with each of these methods. The fossil record is like a movie with most of the frames cut out. Because it is so incomplete, it can be difficult to establish exactly when particular evolutionary changes happened.
Modern genetics allows scientists to measure how different species are from each other at a molecular level, and thus to estimate how much time has passed since a single lineage split into different species. Confounding factors rack up for species that are very distantly related, making the earlier dates more uncertain.
These difficulties mean that the dates in the timeline should be taken as approximate. As a general rule, they become more uncertain the further back along the geological timescale we look. Dates that are very uncertain are marked with a question mark.
