revision class q's Flashcards
What is polygenic inheritance? (
Polygenic inheritance is the genetic transmission of a characteristic whose expression is influenced by alleles at multiple loci. A classic example is human skin colour: production of melanin depends on alleles at several loci with additive effects, resulting in a range of skin colours according to how many dark (as opposed to light) pigmentation alleles the person has inherited.
Give an example of a mechanism of non-genetic, horizontal transmission of behaviour
Behaviour can spread horizontally (i.e. within generations) via social learning, through mechanisms such as local enhancement. Local enhancement is where a ‘demonstrator’ animal performing the behaviour draws the attention of an ‘observer’ animal to a specific location, where the observer subsequently acquires the same behaviour through trial-and-error learning. This is one suggested mechanism for the spread of milk-bottle opening through the UK tit population in the 1940s.
How can a target cell increase its sensitivity to protein hormones?
By increasing the number of receptors in its surface membrane
The correlation between twins in their spatial ability is 0.62 for monozygotic twins reared together, 0.49 for monozygotic twins reared apart and 0.34 for dizygotic twins reared together (Plomin 2005). What does this evidence suggest about genetic and environmental influences on spatial ability?
There is a strong influence of genetic factors and a weaker influence of shared environmental factors on spatial ability.
During sexual differentiation in male mammals, which of the following steps occurs first?
Regression of the Müllerian ducts. Production of SRY protein. Conversion of testosterone to DHT. Formation of the scrotum. Synthesis of testosterone in Leydig cells.
Production of SRY protein
Briefly outline the link between tolerance and withdrawal in addiction.
When you take drugs over a longer period of time, the brain adapts by for example breaking down more of the neurotransmitter the drug is acting upon. This means you need to increase the amount of the drug to get the same high. When you stop taking the drug however, the breaking down continues, which means neurotransmitter levels drop drastically causing withdrawal symptoms
Briefly outline the logic behind ERP
The aim of an ERP is to isolate the average EEG response to a stimulus (for example an image on the screen) by showing the participant the same picture multiple times. You then take the EEG data immediately after each image and compute the average of those EEG sections. This way all the noise in each section is averaged away and only the EEG data that is consistent just after the image remains.
Which of the following iseasilyvisible on the surface of the brain? a. The thalamus. b. The corpus callosum. c. The primary motor cortex. d. The hippocampus. e. The basal ganglia.
c.
The primary motor cortex.
Which of the following statement(s) about split-brain patients is not true?
That their Corpus Callosum is severed as part of their treatment for epilepsy
That they experience severe amnesiaas a consequence ofsurgery
That the left hemisphere of their brains is disconnected from the right hemisphere.
That their behaviour provided evidence of inter-hemispheric processingasymmetrie.
That their behaviour showed thelefthemisphere to be dominant for language
That they experience severe amnesiaas a consequence ofsurgery
Damage to what part of the brain often results in severeamnesia?
The medial temporal lobe
What are the nodes of Ranvier?
Unmyelinated parts of the axon involved in salutatory transmission of axon potentials
Which cells in the primary visual cortex are more sensitive to motion?
Cells that receive input form the parvocellular layers of the LGN
Why are there more congenital ‘colour-blind’ men than women?
Because the most frequent mutations causing genetic defects to the expression of cone opsins are located on the X-chromosome, therefore affecting women less than men
Briefly describe one major functional difference between the two visual streams in the brains of primates (including humans).
Primates have two main cortical visual streams, the ventral processing stream and the dorsal processing stream. The ventral processing stream is responsible for visually identifying objects, while the dorsal processing stream is responsible for perceiving the location of objects and for guiding movement toward them.
