Download Unit 4 Review Sheet - Answers

Unit 4 Review Sheet
Genetics and Biotechnology
Vocabulary
Heredity
Chromosomes
Nitrogenous Bases (what are they?)
DNA Replication
Protein
Protein synthesis
Expressed
Selective Breeding
Gel Electrophoresis
DNA
Genes
Base-Pair Rule
Semi-conservative Model
Transcription
Mutation
Genetic Engineering
Recombinant DNA
Restriction Enzymes
RNA
Nucleotide
Template
Amino Acid
Translation
Allele
Biotechnology
Gene Therapy
Genome
DNA and RNA Structure
- How many strands? DNA = 2, RNA - 1
- What are its building blocks? Nucleotides
- What bases are found in DNA/RNA? DNA = A,T,C,G; RNA = A,U,C,G
- What’s the Base-Pair rule? A pairs with T, C pairs with G
- Where is DNA/RNA found in the cell? DNA is found in the nucleus, RNA is found in the nucleus and
cytoplasm
- What is a chromosome? a piece of DNA How many do we have? 46 (23 pairs) What’s special about sex
chromosomes? sex chromosomes determine gender (XX = female, XY = male)
- How is RNA similar and different to DNA? DNA and RNA are both nucleic acids; DNA is doublestranded, RNA is single-stranded; DNA has deoxyribose, RNA has ribose; DNA has T, RNA has U;
DNA is only found in the nucleus
DNA Replication
- Why is DNA replication “semi-conservative?” When DNA replicates into 2 new DNA molecules, each
new molecule consists of 1 old strand (that acts as a template) and 1 new strand. Semi means ½, so
half the DNA is conserved.
*You do NOT need to know the names of the enzymes involved in this process.
Protein Synthesis
- What is the relationship between DNA, genes and protein? DNA is found in the nucleus and contains
genes. Genes code for protein.
- What is junk DNA? DNA that doesn’t code for anything (most of our DNA is junk!)
- What is transcription? What is translation? Where do these processes occur? Transcription is making
RNA from DNA, occurs in the nucleus; Translation is making a protein from mRNA, occurs at the
ribosome in the cytoplasm
- Do you know how to use the codon chart?
- Why is the sequence of amino acids important to the shape and function of a protein? The sequence of aa
determines the shape of the protein. Proteins have a specific shape and function, therefore have a
specific sequence of aa.
*You do NOT need to know the names of the enzymes involved in this process.
Mutations
- What is a mutation? A change in the DNA sequence.
- What kind of mutations can happen to DNA (i.e. a nucleotide is deleted)? Deletion, insertion.
- Do all mutations result in a faulty protein? Why or why not? No, because if you make mRNA that codes
for same amino acids, you will end up with the same protein. This happens because some codons
code for the same aa.
- What is trisomy 21? What is another name for this disease? Trisomy 21 occurs when an individual has 3
21st chromosomes, also called Down’s Syndrome.
Mendelian Genetics
- How many copies of genes does each of us have? 2 copies of every gene Where do we get each copy
from? 1 copy from each parent
- What’s the difference between dominant and recessive alleles? When you have 2 different alleles, the one
that is expressed is called the dominant allele.
*You do NOT need to know how to do a Punnett Square for this exam.
Gel Electrophoresis
- Can you explain, in 2 sentences, what this lab procedure is? Gel Electrophoresis is a lab procedure used
to separate out different sized fragments of DNA or protein (although we only talk about DNA).
Restriction enzymes cut DNA into fragments, which are loaded into a gel. Smaller fragments move
further through the gel than larger fragments, which produce banding patterns.
- What is the purpose of this laboratory technique? This lab procedure is used to compare DNA samples
to determine relationship between organisms or unknown with known DNA.
- How can this lab technique be used to determine relationships between organisms? Organisms with
similar DNA will produce similar banding patterns.
Nature vs. Nurture
- How can the environment influence gene expression? The environment can turn genes on/off or cause
mutations.
- What kind of environmental factors can influence gene expression? Temperature, pH.
Biotechnology
- What is selective breeding? Selectively choosing organism with desirable traits to produce offspring
(with those desirable traits). Genetic Engineering/Recombinant DNA? Inserting a gene (using enzymes)
into another organism; i.e. insulin gene into bacteria Gene Therapy? Inserting a gene into specific cells
using viruses.
- What is one positive and one negative effect these technologies have had on our society and the
environment? Positive = treat disease, produce offspring with desirable traits; Negative = decrease
diversity in organisms, controversial