Download Genetics Quiz Study Guide

Genetics Quiz Study Guide: 25 Multiple choice questions. 50 pts.
Good things to know:
Terms:
Allele. An alternative form of a gene. E.g. A, B, and O are all different alleles of the
bloodtype gene.
Amino Acid. An organic molecule made of C, H, O, and N that serves as a building
block for proteins and other molecules in living organisms.
Chromosome. An organized structure of DNA and protein found in the nucleus of a
cell. Chromosomes store genetic information for the cell.
Co-dominant. Condition where the phenotypes of both alleles of a particular gene are
expressed simultaneously in a heterozygote, e.g. AB bloodtype.
Codons. Groups of three nitrogen bases in DNA that “code” for the formation of
specific amino acids.
DNA. Deoxyribonucleic Acid. A polymer molecule, composed of sugar, phosphates, and
four nitrogen bases (Adenine, Thymine, Guanine, Cytosine) arranged in a double-helix
pattern. DNA stores genetic trait information through the arrangement of the nitrogen
bases in the double helix structure. Groups of three nitrogen bases form codons.
Dominant. The form (allele) of the gene that appears to dominate or mask another form
of the gene when two different forms are present, i.e. when the individual is
heterogygous (e.g Hh) for that gene. Dominant alleles are often written in capital letters.
Gene pool. All the possible alleles for a particular gene (or all genes) within a given
population.
Genotype. The composition of alleles of an organism, usually for a few specific genes
that are being studied. For example: "A person whose phenotype is type A blood can
have a genotype of AA or AO."
Heterozygous. Having two different alleles of a particular gene, e.g. Hh for hairy
knuckles or AO for bloodtype.
Homozygous. Having two identical alleles of a particular gene, e.g. HH or hh.
Mendelian Inheritance. From Classical Genetics, in sexual reproduction where there
are only two alleles used to determine an expressed trait, Gregor Mendel first predicted
that one gene will be inherited from each parent for the trait and the combination of
these two genes would determine the phenotype.
Phenotype. The observable traits or properties of an organism. Refers to both genetic
and non-genetic traits. Often used to refer to a single trait. For example: "My phenotype
is hairy knuckles and my genotype is Hh."
Population. A local group of individuals belonging to the same species, which are
actually or potentially interbreeding and transmitting traits from parent to offspring.
Protein. A large biological molecule made of chains of amino acids.
Punnett Square. A tool, consisting of a square grid of potential outcomes of offspring
from two parents, used to help predict the results of genetic crosses.
Recessive. The form of the gene that is masked by another form in the heterozygous
condition. For example, the allele for no hair on knuckles (h) is recessive to the allele for
hairy knuckles (H); a person with Hh genotype has hairy knuckles. Recessive alleles are
often written in lower case letters.
Replication. The process by which DNA makes an exact copy of itself.
RNA. Ribonucleic Acid. A single strand nucleic acid, where the sugar used is ribose. A
form of t-RNA carries amino acids to ribosomes for use in protein synthesis. The mRNA (messenger RNA) carries genetic information from the nucleus to the ribosomes.
Trait. Any detectable phenotypic variation of a particular inherited characteristic.
Transcription. The process by which DNA in the forms of genes (mRNA) make copies
of themselves in order to either make proteins or reproduce. In transcription, the mRNA
copies the DNA except that the nucleotide uracil replaces thymine.
Concepts to Understand:
1. The difference between genotype and phenotype
2. The main advantages/disadvantages of sexual vs. asexual reproduction
3. How a Punnett Square can be used to make predictions about offspring
4. Compare a Punnett Square prediction with the random assignment of genes
5. The “rules” by which the nitrogen bases combine in DNA (CG, AT)
6. How DNA transcribes (copies) itself or parts of itself using RNA