1.2 Genetics And Behaviour Flashcards
Mendelian genetics. ____ demonstrated that inheritance occurs through genes, units of heredity that maintain their structural identity from one generation to another.
Mendel
Everything you do depends on both your ____ and your ____.
genes, environment
As a rule, genes come in pairs because they are aligned along ____ (strands of genes) that also come in pairs.
chromosomes
Classically, a gene has been defined as a portion of a chromosome, which is composed of a double-stranded molecule ____ ____ (DNA).
deoxyribonucleic acid
Sometimes several genes ____ on a stretch of chromosome. Sometimes a genetic outcome depends on parts of two or more chromosomes.
overlap
A strand of DNA serves as a template (model) for the synthesis of ____ ____ (RNA) molecules, a single strand chemical.
ribonucleic acid
One type of RNA molecule – messenger RNA – serves as a template for the synthesis of ____ molecules.
protein
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.
amino acids
Some proteins form part of the structure of the body. Others serve as ____, biological catalysts that regulate chemical reactions in the body.
enzymes
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.
homozygous, heterozygous
Genes are dominant, recessive, or ____.
intermediate
A ____ gene shows a strong effect in either the homozygous or heterozygous condition.
dominant
A ____ gene shows its effects only in the homozygous condition.
recessive
The genes on the sex chromosomes (designated X and Y) are known as ___-____ genes.
sex-linked
All other chromosomes are ____ chromosomes, and their genes are known as autosomal genes.
autosomal
Distinct from sex-linked genes are the ___-____ genes, which are present in both sexes, generally on autosomal chromosomes, but active mainly in one sex.
sex-limited
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.
sex hormones
Genes change in several ways. One way is by ____, a heritable change in a DNA molecule.
mutation
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.
epigenetics
Changes in gene expression are also central to learning and memory and to brain changes resulting from ____ ____.
drug addiction
Proteins call ____ bind DNA into a shape that is more like a string wound around a ball.
histones
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.
genetic
A second kind of evidence is studies of adopted children. Any tendency for adopted children to resemble their biological parents suggests a ____ influence.
hereditary
If the variations in some characteristic depend largely on genetic differences, the characteristic has high ____.
heritability
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.
environmental
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.
produces
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.
causes
Genes influence behaviour in ____ ways. We should not be amazed by reports that nearly every human behaviour has some heritability.
roundabout
____ is a change over generations in the frequencies of various genes in a population.
Evolution
____ psychology concerns how behaviours evolved.
Evolutionary
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.
natural
An action that benefits someone other than the actor.
Altruistic behaviour
Selection for a gene that benefits the individuals relatives.
Kin selection
The idea that individuals help those who will return the favour.
Reciprocal altruism
