3.1 Biological Psychology: Genetic Code

These flashcards cover key concepts from the lecture on biological psychology, focusing on genetic inheritance, chromosomes, DNA, genotype versus phenotype, and traits.

What is the principle behind genetic inheritance in humans?

Humans inherit half of their genetic material from their mother and half from their father through chromosomes.

How many chromosomes do humans have?

Humans have a total of 46 chromosomes, which are arranged in 23 pairs.

What determines a person’s biological sex at the genetic level?

A person is genetically female if they have two X chromosomes (XX) and genetically male if they have one X and one Y chromosome (XY).

What is DNA?

DNA stands for deoxyribonucleic acid and is the molecule that carries the genetic blueprint in organisms.

What are the four nucleotide base pairs in DNA?

The four nucleotide base pairs are adenine (A), thymine (T), guanine (G), and cytosine (C).

What is the difference between genotype and phenotype?

Genotype refers to the genetic makeup (the sequence of genes), while phenotype refers to the actual expressed traits.

Can genotype determine phenotype directly?

No, genotype does not guarantee phenotype expression due to environmental factors and interactions.

What does homozygous mean?

Homozygous means that an individual has inherited the same version of a gene from both parents.

What does heterozygous mean?

Heterozygous means that an individual has inherited different versions of a gene from each parent.

What is the significance of dominant and recessive genes?

A dominant gene will always be expressed in the phenotype, while a recessive gene is expressed only if paired with another recessive gene.

What is a trait controlled by a single gene called?

A trait controlled by a single gene is often referred to as a simple Mendelian trait.

What is the expected phenotypic ratio of tasters to non-tasters in the PTC tasting example?

The expected ratio is 75% tasters to 25% non-tasters.

What term describes traits that are controlled by multiple genes?

Traits controlled by multiple genes are referred to as polygenic traits.

What is the notation used to denote dominant and recessive alleles?

Dominant alleles are usually denoted by uppercase letters, while recessive alleles are denoted by lowercase letters.

What example is provided to illustrate the concept of homozygous and heterozygous traits?

Eye color is used to illustrate the concept; a child may inherit different versions of eye color genes from each parent.