TOPIC 1: Genes and Evolution Flashcards
Genes
Functional biochemical units of heredity which that make up the chromosomes
Proteins
basic chemicals that make up the structure of cells and direct their activities
Gene expression
whether a gene is turned on or off (whether it produces protein)
Genotype
has to do with genes / an organism’s specific set of genes
Phenotype
has to do with the environment / overt traits and behaviour of an
organism
Heterozygote
whenever a dominant gene is present, it is expressed
Homozygote
a recessive gene is only expressed when matched with a similar gene
Heritability
A statistical estimate of the extent to which variations in a trait within a
population is due to genetics.
Monozygotic twins
twin siblings that result from one zygote splitting in two and therefore share the same genes
Allele
a variant form of a gene
Genome
The set of complete instructions of making an organism (all the genes in the organism)
Dominant gene
A gene that is expressed in the offspring whenever it is present
Recessive gene
A gene that is expressed only when it is matched with a similar gene from the other parent
Polygenic characteristic
When a population displays a range of variability for a certain characteristic, such as height or intelligence
Epigenetics
how environment affects genetic expression
Survival of the genes
individuals with a certain trait survive and reproduce at a higher rate
than others. The trait associated with this advantage is passed on and even better
represented in within the next generation.
Chromosomes
Structures within the cell body that are made up of DNA, segments of which
compromise individual genes.
Heredity
Transmission of characteristics from parents to offspring through genes.
What influences gene expression?
the environment outside the cell, timing in development, the overall environment, experience, behavior
Twin studies
monozygotic (identical) twins are compared to dizygotic
twins. Result: monozygotic twins are more alike, so genetic influence is
there.
adoption studies
compare similarities between biological and adopted
relatives (same environment, different genes) Result: growing up in the
same home does cause little similarity. Sometimes, twins raised apart are
more alike than when they live together because then parents try to force
individuality
