Flashcards in 1.2 Genetics And Behaviour Deck (39):
Everything you do depends on both your ____ and your ____.
Mendelian genetics. ____ demonstrated that inheritance occurs through genes, units of heredity that maintain their structural identity from one generation to another.
As a rule, genes come in pairs because they are aligned along ____ (strands of genes) that also come in pairs.
Classically, a gene has been defined as a portion of a chromosome, which is composed of a double-stranded molecule ____ ____ (DNA).
Sometimes several genes ____ on a stretch of chromosome. Sometimes a genetic outcome depends on parts of two or more chromosomes.
A strand of DNA serves as a template (model) for the synthesis of ____ ____ (RNA) molecules, a single strand chemical.
One type of RNA molecule – messenger RNA – serves as a template for the synthesis of ____ molecules.
DNA contains four bases – ____, ____, ____, and ____ – in any order.
adenine, guanine, cytosine, and thymine
The order of DNA bases determines the order of corresponding bases along an RNA molecule – ____, ____, ____, and ____.
adenine, guanine, cytosine, and uracil
The order of bases along an RNA molecule in turn determines the order of ____ ____ that compose a protein.
Some proteins form part of the structure of the body. Others serve as ____, biological catalysts that regulate chemical reactions in the body.
Anyone with an identical pair of genes on the two chromosomes is ____ for that gene. An individual with an unmatched pair of genes is ____ for that gene.
Genes are dominant, recessive, or ____.
A ____ gene shows a strong effect in either the homozygous or heterozygous condition.
A ____ gene shows its effects only in the homozygous condition.
The genes on the sex chromosomes (designated X and Y) are known as ___-____ genes.
All other chromosomes are ____ chromosomes, and their genes are known as autosomal genes.
Distinct from sex-linked genes are the ___-____ genes, which are present in both sexes, generally on autosomal chromosomes, but active mainly in one sex.
Examples of sex-limited genes include the genes that control the amount of chest hair in men or breast size in women. Both sexes have those genes, but ___ ____ activate them and one sex or the other.
Genes change in several ways. One way is by ____, a heritable change in a DNA molecule.
Another kind of mutation is a ____ or ____. During the process of reproduction, part of a chromosome that should appear once may instead appear twice or not at all.
duplication or deletion
The field of ____ deals with changes in gene expression without modification of the DNA sequence.
Changes in gene expression are also central to learning and memory and to brain changes resulting from ____ ____.
Proteins call ____ bind DNA into a shape that is more like a string wound around a ball.
To determine the contributions of ____ and ____, researchers rely mainly on two kinds of evidence. First, they compare monozygotic twins and dizygotic twins.
heredity and environment
A stronger resemblance between monozygotic than dizygotic twins suggests a ____ contribution.
A second kind of evidence is studies of adopted children. Any tendency for adopted children to resemble their biological parents suggests a ____ influence.
If the variations in some characteristic depend largely on genetic differences, the characteristic has high ____.
Researchers sometimes also examine "virtual twins" – children of the same age, adopted at the same time into a single family. Any similarities in behaviour can be attributed to ____ influences.
A biologist who speaks of a "gene for brown eyes" does not mean that the gene directly ____ brown eyes. The gene produces a protein that makes the eyes brown, assuming normal health and nutrition.
If we speak of a "gene for alcoholism", we should not imagine that the gene it self ____ alcoholism. Rather, it produces a protein that under certain circumstances increases the probability of alcoholism.
Genes influence behaviour in ____ ways. We should not be amazed by reports that nearly every human behaviour has some heritability.
____ is a change over generations in the frequencies of various genes in a population.
____ psychology concerns how behaviours evolved.
The emphasis in evolutionary psychology is on ____ and ____ explanations – that is, the presumed genes of our ancestors and why natural selection might have favoured genes that promote certain behaviours.
evolutionary and functional
The assumption of evolutionary psychology is that any behavioural characteristic of a species arose through ____ selection and presumably provided some advantage.
An action that benefits someone other than the actor.
Selection for a gene that benefits the individuals relatives.