Chapter 3 - Section 1 Review of Basic Genetic Mechanisms Flashcards
What is adaptation?
Adaptation refers to modification as a result of changed life circumstances. (p. 58)
What is evolution?
Evolution is the long-term adaptive process, spanning generations, that equips each species for life in its ever-changing natural habitat. (p. 58)
How can genes affect behavioral traits through their role in protein synthesis?
Genes never produce or control behavior directly. All the effects that genes have on behavior occur through their role in building and modifying the physical structures of the body. Those structures, interacting with the environment, produce behavior. (p. 58)
Environment, as used in this context, refers to every aspect of an individual and his or her surroundings except the genes themselves. (p. 59)
Genes affect the body’s development through, and only through, their influence on the production of protein molecules. We are what we are, biologically speaking, because of our proteins. A class of proteins called structural proteins forms the structure of every cell of the body. Another, much larger class called enzymes controls the rate of every chemical reaction in every cell. (p. 58)
What are genes?
Genes are components of extremely long molecules of a substance called DNA (deoxyribonucleic acid).
These molecules exist in the egg and sperm cells that join to form a new individual, and they replicate themselves during each cell division in the course of the body’s growth and development.
Each protein molecule consists of a long chain of smaller molecules called amino acids. (p. 58)
What are coding genes?
They code for unique protein molecules. (p. 59)
What are regulatory genes?
They work through various biological means to help activate or suppress specific coding genes and thereby influence the body’s development.
Recent research comparing human and chimpanzee DNA suggests that the biggest genetic differences between the two species lie in certain regulatory genes that affect the development of the brain. (p. 59)
How are genes involved in the long-term behavioral changes that derive from experience?
There is good reason to believe that all sorts of prolonged behavioral effects that derive from experience, including those we call “learning,” involve the activation of genes. The experience activates genes, which produces proteins, which in turn alter the function of some of the neural circuits in the brain and thereby change the manner in which the individual behaves. (p. 60)
What is genotype?
The set of genes that the individual inherits.
The same genes can have different effects, depending on the environment and the mix of other genes. (p. 60)
What is phenotype?
The observable properties of the body and behavioral traits. (p. 60)
What are chromosomes?
The genetic material (strands of DNA) existing in each cell in structures, which are usually dispersed throughout the cell nucleus.
The normal human cell has 23 pairs of chromosomes.
Genetically, the only difference between the sexes is that females have two X chromosomes (XX - a true pair) rather than the XY of the male.
