An exercise that uses a common bacterium, E. coli, in great numbers, to detect a demonstrable change in the ability of some cells to become resistant to the common antibiotic streptomycin is presented. The procedure for preparing and pouring the gradient antibiotic plates is provided. The advantages of using the Basic Fuchsin in the agar are…

Parents of 21 well-functioning autistic children were examined. Clinical details of the eight parents diagnosed as schizoid are analyzed, leading to the conclusion that one etiological factor may be a genetic predisposition to schizoid personality traits. Global and specific developmental delays in the autistic children's siblings were not found.…

The prevalence of epilepsy was correlated with the severity and type of encephalopathy of 1,023 individuals with mental retardation. A total of 326 individuals were diagnosed with epilepsy. Results indicated a low percentage of epilepsy in chromosomic-genetic and young adult encephalopathies and a high prevalence when the neurodeficit was…

A total of 127 pairs of twins completed a measure of personality at 20 and 30 years of age. Analyses revealed that variance in negative emotionality was the result of diminishing genetic influence; personality stability was the result of genetic factors; and personality change was the result of environmental factors. (BC)

Assessed the family environment and personality of 400 pairs of 59-year-old twins. Genetic influences on extraversion and neuroticism were related to genetic influences on the family environment factors of relationship and personal growth but not to the factor of system maintenance. (BC)

Mothers attributed their children's outcomes to either child-rearing practices, genetics, or environment. It was predicted that mothers of only children and gifted children would attribute more importance to child rearing than would mothers of multiple children and special education children. Predictions were supported across academic, social, and…

Rapid-cycling brassicas can be used in the classroom to teach concepts such as plant growth, tropisms, floral reproduction, pollination, embryonic development, and plant genetics. Directions on how to obtain them for classroom use and how they may be grown are included. Practical physiology and genetics exercises are listed. (KR)

Applies inverse Bayesian analyses to data from three large family studies of reading disability to estimate posterior probability that an offspring will be affected. Finds that offspring risk rates were significantly elevated if a parent reported a history of reading disability. Suggests the use of family history as a component in clinical…

Investigates genetic influences on reading in a sample of 285, 13-year-old twins. Finds the heritability of disability for reading recognition to be nonsignificant but that spelling had a substantial genetic contribution to all levels of disability. Suggests two possible independent aspects of phonological ability, each influenced by genetic…

Applies an extension of an earlier multiple regression model for twin analysis to the problem of detecting linkage in a quantitative trait. Detects a number of possible linkages, indicating that the approach is effective. Discusses detecting genotype-environment interaction and the issue of power. (RS)

Dramatic developments in brain research and imaging technology are rapidly advancing our understanding of the human brain. The new biologically based brain theories suggest that "nature" dominates "nurture" and that many current beliefs about instruction, learning, and memory are wrong. This article explains neural Darwinism…

A study involving 55 children with a language impairment and 76 with normal language investigated the heritability of auditory processing impairment in same-sex twins (ages 7 to 13, selected from a sample of 37 pairs). Although correlations between co-twins were high, lack of significant difference between monozygotic and dizygotic twins suggested…

"Authorized" genetic testing may be obtained from employees with coercion or threat. Unless protections are put in place, employers and health insurers will use genetic screening to hire and fire. (JOW)

Provides directions for the construction of giant plastic cells, including details for building and installing the organelles. Also contains instructions for preparing the ribosomes, nucleolus, nucleus, and mitochondria. (DDR)

Describes a laboratory procedure using vanilla and chocolate sandwich cookies that can be used to illustrate independent assortment either during meiosis or during a dihybrid cross. (DDR)