Biology 101 final review

Concepts – Chapter 10

Hershey and Chase experiments (10.1)

Hershey and Change mixed radioactively labeled phages with bacteria, they agitated the cultures in a blender to separate the phages outside of the bacteria, they centrifuged the mixture so that the bacteria formed a pellet, and finally, they measured the radioactivity in the pellet and liquid

Phage replication (10.1)

A phage attaches itself to a bacteria cell, the phage injects its DNA into the bacterium, the phage DNA directs the host cell to make more phage DNA, The cell lyses and releases the new phages

DNA structure (10.2)

DNA structure is double helix

DNA vs. RNA (10.2)

DNA is deoxyribose while RNA is sugar ribose and RNA has the base Uracil instead of Thymine

4 nitrogenous bases & base pairing (10.2)

A pairs with T, forming two hydrogen bonds, and G pairs with C, forming three hydrogen bonds.

Watson, Crick, Franklin, Wilkins – DNA helix (10.3)

Watson and Crick reported that DNA consisted of two polynucleotide strands wrapped into a double helix.

Direction of DNA replication (10.4)

DNA replication occurs in the 5´ to 3´ direction.

What is the process of making protein from DNA? (10.6/10.7)

Transcription

What is the start codon? (10.8)

AUG
What are the 3 phases of transcription and translation? Where do they take place? (10.9)

Initiation, Elongation, and Transcription

Role of RNA polymerase? (10.8)

It links the RNA nucleotide which readies them for transcription

What is splicing/when does it occur? (10.9)

RNA splicing removes introns and joins exons to produce a continuous coding sequence. What are the 3 different types of RNA? What do they do?

mRNA (messenger RNA): It encodes genetic information from DNA and conveys it to ribosomes, where the information is translated into amino acid sequences rRNA (ribosomal RNA): creates RNA with protein tRNA (transfer RNA): it serves as an interpreter in translation, has anticodon UAC

What are P and A sites? How do mRNA and tRNA work together? (10.12)

The first tRNA occupies the P site, which will hold the growing peptide chain. The A site is available to receive the next tRNA.

Terms – Chapter 10

Semiconservative model: Type of DNA replication in which the replicated double helix consist of one old strand, derived from the old molecule, and one newly made strand

Parent strand/Template: used to describe processes such as DNA replication Complementary Strand: a section of one nucleic acid chain that is bonded to another by a sequence of base pairs.
Nucleotides: The building block of nucleic acids, consisting of five-carbon sugar covalently bonded to a nitrogenous base and one or more phosphate groups

DNA/RNA polymerase: adds nucleotides to a growing chain and proofreads and corrects improper base pairings.

DNA ligase: repairs DNA damaged by harmful radiation or toxic chemicals

Promoter: The “start transcribe” signal in a nucleotide sequence

Introns: interrupting sequences that separate

Exon: the coding regions

Concepts – Chapter 11

What are regulatory genes and how do they work (11.1)?

Helps to control operons by coding for repressor

How does the lac operon work? Trp operon (11.1)?

In a lac operon, a regulatory gene, located outside the operon, codes for a repressor protein, and then it binds to the operator and prevents RNA polymerase action. And in a Trp operon, it assists with the control of amino acid regulation

What factors can control gene expression – see slides (11.3,
11.4, 11.5, 11.6)?

Transcription factors, Enhancers, RNA splicing, Small RNAs, Long lived mRNA, Inhibitory proteins

What is differentiation (11.2)?

Differentiation describes fate of the cell with a specific function and structure

Techniques for studying gene expression (11.9)

DNA microarrays

How do proto-oncogenes turn into oncogenes and cause problems (3 ways) (11.16)?

1. Accumulation may cause hyperactive production of proteins

2. Multiple copies of the gene may be made, thus causing the production of extra protein

3. The gene may be moved to a new location, making excessive protein

What do tumor suppressor genes do (11.16)?

They inhibit cells division and regulate uncontrolled cell growth.

What are the different types of cancer? How does cancer progress? Is more than one mutation needed? (11.17) –Carcinomas (external/internal coverings)
–Sarcomas (tissues- bone/muscle)
–Leukemias (blood/bone marrow)
–Lymphomas (immune system)
Cancer progresses when one or more genes that encode for a protein become mutated, mutant cells should be destroyed but evade destruction

Chapter 11 - Terms

Regulatory gene: Helps to control operons by coding for repressor

Operon: cluster of genes with related functions and control sequences

Promoter: short sections of DNA that control enzyme sequence

Operator: determines if RNA promoters can bind and start transcribing genes

Active/Inactive Repressor: can bind and inhibit transcription by inhibiting RNA and polymerase from binding

Concepts – Chapter 12

What is genomics (12.17)?

The study of who sets of genes and their interactions

What is the whole-genome shotgun approach (12.19)?

1. Use restriction enzyme to cut into fragment
2. Clone and sequence fragments

3. Computers can assemble onto physical map

Concepts – Chapter 13

Artificial vs. Natural selection (13.2)

Artificial selection is selection for individuals with desired traits, and Natural Selection states that individuals with certain traits are more likely to survive and reproduce

What are some examples of natural selection (Galapagos Island
Finches/Beak Size, Pesticide Resistance, Antibiotic Resistance) (13.3)

Peppered Moths in industrialized countries

What are some ways in which scientific evidence supports the theory of evolution? (13.5)

Biogeography: geographic distribution of species

Homologous structures: structures that have different, but are similar in structure due to common ancestry (often seen in anatomical structures)

Vestigial structures: structures with no specific current function but were of importance to ancestors

Molecular DNA: genome similarity

What are 2 things that cause genetic variation? (13.8)

• Mutation: changes in nucleotide sequence

•Sexual Reproduction: combinations of different alleles

What is microevolution? (13.7)

A change in a population’s gene pool over generations

What are the 3 types of mutations discussed in class that lead to genetic variability? (10.16)

Silent mutations: cause no change in protein product

Missense mutations: cause a change in amino acid coding

Nonsense mutations: change amino acids into stop codons

What are the 5 requirements necessary for Hardy Weinberg equilibrium? (13.9)

Very large population

No gene flow between populations

No mutations

Random mating

No natural selection

What is the Hardy Weinberg equation? (13.9) Hardy Weinberg principle – regardless of the # of times that an allele is segregated into different gametes and combined during fertilization in a specific population, the frequency of each allele will remain constant

In what 3 ways can natural selection alter variation in a population?
(13.13)

Stabilizing Selection
Directional Selection
Disruptive Selection

Terms – Chapter 13

Gene flow: Population may gain or lose alleles when fertile individuals leave or enter a population

Microevolution: a change in a population’s gene pool over generations

Genetic Drift: chance events cause allele frequency to change between generations

Bottlenecking event: only certain groups survive

Founder effect: few individuals within populations move to new geographic area and do not represent larger population