Quiz: Genetics Flashcards
Define population genetics
Deals with a group of individuals of the same species, like if we studied the gene pool of a group of humans.
Organismal genetics
Deals with one individual, like if we studied the genome (all of the genes) of just one human.
Molecular genetics
Deals with the molecules that genes are made of, like if we studied just one gene inside of one human.
Nucleic acid
A complex organic substance present in living cells, especially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain.
Gene
A distinct sequence of nucleotides forming part of a chromosome, the order of which determines the order of monomers in a polypeptide or nucleic acid molecule which a cell (or virus) may synthesize.
Diploid
Having two complete sets of paired chromosomes, one from each parent.
Haploid
Having a single set of unpaired chromosomes.
Who figured out the basic rules of genetics?
Gregor Mendel
A gene mutation may result in what three outcomes?
The mutated codon is now a stop codon, severely shortening the polypeptide. The protein will no longer function.
or
The mutated codons now codes for a different amino acid, which alters the structure of the polypeptide. If the protein is still functional, it may be inhibited by its different structure, seen in sickle cell anemia. The changed polypeptide may also benefit the organism with a positive phenotype, which fuels evolution.
or
Because different arrangements of bases can code for the same amino acid, a mutated codon could code for the same amino acid as before. Effectively, the mutation did not change anything about the polypeptide ― hence, it is “silent.”
Each nucleotide consists of which three components?
A phosphate, a sugar, and a base.
In DNA, Adenine (A) always bonds with ___ and Cytosine (C) always bonds with ___.
Adenine pairs up with Thymine (T)
Cytosine pairs up with Guanine (G)
In RNA, Adenine (A) always bonds with ___ and Cytosine (C) always bonds with ___.
Adenine pairs up with Uracil (U)
Cytosine pairs up with Guanine (G)
Transcription is when…
The DNA letters are copied (transcribed) into RNA letters, when the DNA molecule produces a messenger RNA (mRNA) molecule.
the process by which genetic information represented by a sequence of DNA nucleotides is copied into newly synthesized molecules of RNA, with the DNA serving as a template.
Translation is when…
The mRNA molecule is translated into a different language, in this case the amino acid language.
During translation…
Workers (ribosomes and tRNA) must assemble the materials (amino acids) according to the instructions.
Ribosomes has two parts: large sub-unit for tRNA, small sub-unit for mRNA. Large sub-unit has two rooms (P and A sites).
Each tRNA has a binding site for a specific amino acid; binds with anti-codon. They bind free amino acids in the cytoplasm, and will then seek out ribosomes.
Explain 2 structural ways in which DNA and RNA differ:
DNA has base pairings A-T and G-C, and the sugar in DNA is called deoxyribose.
RNA has base pairings A-U and G-C, and the sugar in RNA is called ribose.
All life as we know it shares the same translating dictionary, what is it called and how does it work?
The translating dictionary translates nucleotides from RNA into codons in amino acids. For example, CAT is translated into GUA, which is part of the Valine amino acid.
What does GM stand for?
Genetically modified
What is gene therapy?
The transplantation of normal genes into cells in place of missing or defective ones in order to correct genetic disorders.
What disease was gene therapy recently used to cure? How?
Gene therapy was recently used to cure Severe Combined Immune Deficiency. They took the bone marrow, isolated the the early cells of the bone marrow (stem cells), and paired those cells with the virus that contains the working copy of the gene. These new cells are then given back to the patient.
What is the Human Genome Project?
The Human Genome Project was a massive scientific attempt to determine the nucleotide sequence of all the DNA in the human genome and to identify the location and sequence of every gene. It began in 1990. What they found was a relatively small number of human genes (currently estimated to be 22,000).
How do you sequence a genome, what are some of the steps involved?
Because genomes cannot be sequenced all at once, scientists must break the genomes into small pieces, and then reassemble them in the correct order to arrive at the sequence of the whole genome.
Cloning: involves breaking the genome up into big chunks called clones. Scientists use genome mapping techniques to figure out where in the genome each clone belongs. Then they cut the clones into smaller pieces, and then use the overlaps to reconstruct the sequence of the whole clone.
Whole-genome shotgun: involves breaking the genome into smaller pieces, sequencing the pieces, and and reassembling the pieces into the full genome sequence.
What is DNA fingerprinting?
The analysis of DNA from samples of body tissues or fluids in order to identify individuals.
What is gel electrophoresis and how does it work?
It is a laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size. In gel electrophoresis, the molecules to be separated are pushed by an electrical field through a gel that contains small pores.
