Brain Size and Intelligence
Background: Is brain size a measure of intelligence? Brain size tends to vary with body size: for example, sperm whales and elephants have brains up to five times as massive as human brains. So across species, brain size is not a perfect measure of intelligence. And within species, the underlying organization (complexity of connections) and molecular activity of the brain are likely to be more directly associated with intelligence than mere size.
In this assignment, we will investigate relationships between physiological measures of the brain, and intelligence. Download and open the Excel workbook, MHA610_Week 5_Assignment_Brain_Data.xls. The workbook contains data on 20 youths, in rows two through 21. Eight variables (the columns) were recorded on each individual; the column headings are given in row one. The column headings are as follows:
IQ
the individual’s IQ
Order
the birth order (1 = firstborn, 2 = not firstborn)
Pair
marker for genotype
Sex
gender, 1 = male, 2 = female
CCSA
corpus callosum surface area (in cm2)
HC
head circumference (in cm)
TOTSA
total brain surface area (in cm2)
TOTVOL
total brain volume (in cm3)
WEIGHT
body weight (in kg)
The neuroanatomical measures CCSA, TOTSA, and TOTVOL were determined from magnetic resonance imaging (MRI) of the brains, followed by automated image analyses of the scans. The corpus callosum is a bundle of neural fibers beneath the cortex, connecting the left and right cerebral hemispheres of the brain; it is the communication highway between the two hemispheres. (The more lanes to the highway, the faster the traffic ought to flow.)
The following questions can be answered in Excel, StatDisk, or other statistics software you may have available.
- Examine all of the pairwise correlations among the physiological measures CCSA, HC, TOTSA, TOTVOL, and WEIGHT. Which two variables have the strongestcorrelation? Report the correlation, and plot the scattergram for these two variables. Also, report the correlation and plot the scattergram for the two variables that have the weakest correlation.
- Determine whether the physiological parameters CCSA, HC, TOTSA, TOTVOL, and WEIGHT are significant predictors of IQ. That is, run a sequence of univariate regressions, with IQ as the dependent variable, and the physiological parameters as the independent variables. Report the best univariate regression with statistics and a graph of the regression. Describe whether IQ can be accurately predicted from any of these brain measures individually or in combination.
BONUS. Power law distributions, that is, functional relationships between two variables in which one variable is roughly a power of the other, are often used to model physiological data. One of the oldest power laws, the square-cube law, was introduced by Galileo in the 1600’s: empirically, the square-cube law states that as a shape grows in size, its volume grows faster than its surface area. We shall investigate the square-cube law with two variables from our dataset, CCSA and TOTVOL. If CCSA varies with some power of TOTVOL, for example, CCSA = k * (TOTVOL) ? (k is an unknown constant here), then a simple way of estimating the exponent ? is via linear regression: take log(CCSA) as the dependent variable and log(TOTVOL) as the independent variable; the fitted regression coefficient (slope) is an estimate of the exponent. (Do you see why this is true?) Perform this linear regression, and report your results. Describe whether the regression coefficient is significantly different from 2/3. (The 2/3rd power law occurs often in nature.)
What is the average fitness per individual
/in /by CarlosSickle-cell anemia is caused by a mutation in the ß-globin gene. Heterozygotes for the Hbs disease allele have some protection from malaria relative to wild-type, but Hbs homozygotes rarely live to produce offspring. 50 individuals homozygous for the normal (non-disease) allele produced a total of 47 children. 50 heterozygous individuals produced a total of 55 children. 50 Hbs homozygous individuals produced a total of 0 children. What is the average fitness per individual of the heterozygotes? What is the relative fitness of the homozygous normal individuals?
Compute the expected number of each genotype
/in /by CarlosA population of snap dragons 77 red flowered individuals,144 pink flowered individuals,and 34 white flowered individuals.Compute the EXPECTED number of each genotype based on hardy weinberg equilibrium. Compare them to observed numbers using a chi-square test of observed and expected values(note in this case degree of freedom are 1 not 2 because you are computing the three genotype frequencies from p and q.What is the value of chi square?
Regulation of physiological processes experiment
/in /by CarlosRegulation of germination
Regulation of Physiological Processes Experiment (Starch-agar plates, GA, ABA, and glucose pr sucrose)
Qs are related to theGA and Amylase lab
*How does the concentration of a hormone affect the physiological response and the presence of one hormone block alter the action of another?
*Does the concentration of sugaravailable to the embryo alter the hormone response andthe embryo it self have a hormone response that is different from the endosperm?
*Does salt or other stress activate theABA repose or Ca2+ incvolved in the reponse of the seed to ABA/
Making reaction, Assume you are given a primer with a
/in /by CarlosAssume you are given a primer with a concentration of 1.4 mg/ml, RNA concentration of 0.8 mg/ml, 1M MgCl2, 10mM dNTP mix, 10x buffer, 10 units/ul of reverse transcriptase. Describe how to make the following reaction:
5mM MgCl2
1x buffer
1mM dNTP mix
10ng of primer 1
10ng of primer 2
1ug of Rna
0.25 units of reverse transcriptase
Final reaction 20ul
Solution-Problem regarding the brain size and intelligence
/in /by CarlosBrain Size and Intelligence
Background: Is brain size a measure of intelligence? Brain size tends to vary with body size: for example, sperm whales and elephants have brains up to five times as massive as human brains. So across species, brain size is not a perfect measure of intelligence. And within species, the underlying organization (complexity of connections) and molecular activity of the brain are likely to be more directly associated with intelligence than mere size.
In this assignment, we will investigate relationships between physiological measures of the brain, and intelligence. Download and open the Excel workbook, MHA610_Week 5_Assignment_Brain_Data.xls. The workbook contains data on 20 youths, in rows two through 21. Eight variables (the columns) were recorded on each individual; the column headings are given in row one. The column headings are as follows:
IQ
the individual’s IQ
Order
the birth order (1 = firstborn, 2 = not firstborn)
Pair
marker for genotype
Sex
gender, 1 = male, 2 = female
CCSA
corpus callosum surface area (in cm2)
HC
head circumference (in cm)
TOTSA
total brain surface area (in cm2)
TOTVOL
total brain volume (in cm3)
WEIGHT
body weight (in kg)
The neuroanatomical measures CCSA, TOTSA, and TOTVOL were determined from magnetic resonance imaging (MRI) of the brains, followed by automated image analyses of the scans. The corpus callosum is a bundle of neural fibers beneath the cortex, connecting the left and right cerebral hemispheres of the brain; it is the communication highway between the two hemispheres. (The more lanes to the highway, the faster the traffic ought to flow.)
The following questions can be answered in Excel, StatDisk, or other statistics software you may have available.
BONUS. Power law distributions, that is, functional relationships between two variables in which one variable is roughly a power of the other, are often used to model physiological data. One of the oldest power laws, the square-cube law, was introduced by Galileo in the 1600’s: empirically, the square-cube law states that as a shape grows in size, its volume grows faster than its surface area. We shall investigate the square-cube law with two variables from our dataset, CCSA and TOTVOL. If CCSA varies with some power of TOTVOL, for example, CCSA = k * (TOTVOL) ? (k is an unknown constant here), then a simple way of estimating the exponent ? is via linear regression: take log(CCSA) as the dependent variable and log(TOTVOL) as the independent variable; the fitted regression coefficient (slope) is an estimate of the exponent. (Do you see why this is true?) Perform this linear regression, and report your results. Describe whether the regression coefficient is significantly different from 2/3. (The 2/3rd power law occurs often in nature.)