Genetics Test Study Guide

Gene

Gene

A section of DNA, which is transferred from a parent to offspring and determines some characteristics of the offspring

Chromosome

Compacted DNA; we are made up of 23 chromosomes

DNA

Deoxyribonucleic acid is the molecule that carries genetic information

Offspring

Descendant, product of reproduction

Recessive

Gene whose expression is suppressed by a dominant

Dominant

Gene that is always expressed

Genetics

Study of inheritance

Heterozygous

Having different alleles for a particular trait

Homozygous

Having the same alleles for a particular trait

Purebred

Having the same alleles for a particular trait

Hybrid

Having different alleles for a particular trait

Genotype

Genetic makeup

Phenotype

Physical appearance

What is the difference between a gene and an allele?

A gene is a section of the DNA molecule that codes for a protein and allele is a variation of the gene

How do we have two copies of each gene?

The sperm cell contains one copy, while the egg cell also contains another copy

How are traits determined?

Traits are determined by proteins; These proteins are determined by the genes.

Is having brown hair a phenotype or genotype?

Phenotype

Can you tell someone’s genotype just by looking at them?

No, because genotype is the genetic makeup of an organism

What are the four different types of bases?

Adenine-Thymine, Cytosine-Guanine

What does DNA code for?

DNA codes for proteins

Explain the relationship between DNA, protein, and trait?

The DNA codes for the proteins. Each nucleotides in a gene determine the proteins. These proteins have functions that affect the organism’s trait.