AIR Biology Review DNA RNA PROTEIN SYNTHESIS HEREDITY

AIR Biology Review DNA & RNA, PROTEIN SYNTHESIS, HEREDITY & EVOLUTION

DNA Replication – making a copy of DNA Why does a cell do it? So the cell can reproduce www. lewport. wnyric. org/jwanamaker/animations. htm

What is the complementary strand of the DNA shown? A T T G C T A T C G A

Answer A T T G C T A T C G A T A A C G A T A GC T

How do we get from gene to protein? DNA RNA Protein transcription translation

Transcription The process of transferring information from DNA to m. RNA Occurs in nucleus

RNA

What RNA strand would be made from the DNA shown? A T T G C T A T C G A G

Answer T O N es o d A RN ! R BE M ! E REM thymine have A T T G C T A T C G A G m. RNA: U A A C G A U A GC U C codon 2 codon 3

2. Translation – synthesizing a protein • Takes place in cytoplasm on ribosomes • Reads m. RNA codons to put amino acids in order to make a protein

Amino Acid Codon Chart

Genetic Mutations Any change in the genetic code R ! D A EB U NO LM L A T A S N TATIO

Mutations in somatic cells cannot be passed down. Mutation in a gamete MIGHT be passed down.

Sickle Cell Anemia

ANSWER

GENETICS

Gregor Mendel: Father of Genetics

Genes= Sections of DNA that control our traits Alleles= different forms of a gene Example: Height of plant could be Tall and Short Dominant: Stronger allele that can over power the weaker allele T=tall Recessive: The weaker allele. t=short

Is a code for proteins

Genotype actual alleles an individual has for a trait Homozygous Both alleles are the same Ex. BB or bb Heterozygous Both alleles are different Ex. Bb

Phenotype Physical appearance Tall or short

Punnett Square Review Cat fur color Black is dominant: B White is recessive: b Cross a white cat with a heterozygous black cat. What is the chance of having another white kitten in the litter? Bb bb

Results of Punnett Square 50% Hybrid Black and 50% Purebred White bb x Bb Bb b b B Bb Bb b bb bb

Pedigree Analysis female Male

Mendel’s Laws 1. Law of Dominance 2. Law of Segregation – alleles separate when forming gametes 3. Law of Independent Assortment: Alleles segregate independent from one another

Law of Indep. Assortment

Multiple Alleles Definition Three or more alleles of the same gene that code for a single trait as in blood type. Example: A, B, O alleles

karyotype

Sex Determination 23 pairs of chromosomes in every cell (46) 1 st-22 nd pair are autosomes Pair 23 are reproductive chromosomes Females XX Males XY

X-linked Traits Some traits only exist on the X chromosome. If there is a mutation on a gene that is located on the X chromosome, it is called an X-linked disorder. Ex: Color blindness, muscular dystrophy, male pattern baldness, and hemophilia. Boys are most often affected and inherit it from their mother �

What is the chance that a man who is normal but a woman who is a carrier for hemophilia will have a child with hemophilia?

Let’s Check What You Know…

Biotechnology EMERGING ISSUES IN GENETICS

DNA Electrophoresis A technique used to separate compounds such as DNA and protein based on size by applying an electrical field.

Genetic Engineering 1. Cut genes out with restriction enzymes 2. Paste them into a bacterial plasmid = makes recombinant DNA

Genetically Modified Organisms Examples: Animals ◦ Bacteria can “eat” oil and radioactive wastes ◦ Extra growth hormone genes to grow faster Plants ◦ Disease & insect resistance ◦ More nutritional value ◦ Bigger, tastier fruits & veggies

Bacteria have been engineered (genetically modified) to make pharamceuticals

Cloning Clone = genetically identical cells produced from a single cell Dolly, the sheep, was a clone Ethical issues? Uses? ◦ Medical ◦ Save endangered species

Stem Cell Research Can develop into any type of cells

Human Genome Project Attempt to sequence all of Human DNA ◦ About 25, 000 genes Find and map all genes Completed in 2000 Still lots of work!

Gene Therapy An absent or faulty gene is replaced by a normal working gene

Why can bacteria recognize a human gene and then produce a human protein?

What process best explains how a nerve cell and a muscle cell can both develop from the same fertilized egg? A. differentiation B natural selection C. selective breeding D. genetic engineering

Evolution & Classification

Evolution: Major Ideas • Evolution - changes in a species over successive generations, based on changes in gene frequency. • Through evolution, a species is able to adapt to changes in its environment. • Charles Darwin explained biological evolution through natural selection.

Evidence for Evolution 1. Fossils 2. Biochemistry: DNA or protein (amino acid sequences) 3. Biogeography 4. Comparative Anatomy: Homologous Structures, vestigial structures

New evolution focuses on Gene Pool Larger gene pool = BETTER!

4 Forces that Can Act to Change Gene Pool

1. Natural Selection When nature chooses the most favorable variation Must have: ◦ Struggle to Survive - a selection pressure ◦ Variation in the Population Those individuals that are most fit to overcome the selection pressure will survive the best, reproduce, and pass down their adaptations! ☺ Ex: giraffes struggle to reach leaves → only tall giraffes survive and reproduce

2. Mutation

3. Gene Flow Immigration & emigration

4. Genetic Drift Changes in gene pool of small population by chance event Founder effect

Remember… less difference = closer related

Hardy-Weinberg Equilibrium Populations are not evolving (gene frequencies are stable) as long as the following conditions are happening: No sexual selection

Classification & Evolutionary Relationships

Cladogram/Phylogenetic Tree Show Evolutionary Relationships

Let’s check…

Scientists study the evolutionary relationships of species to better understand the history of life on Earth. Describe two methods that scientists can use to determine whether two species (modern or extinct) are closely related. Type your answer in the space provided.

The End

An individual has his appendix removed, dyes his hair black, and intentionally gorges on food until he is morbidly obese. Which of these traits is likely to be passed on to any offspring? A. Obesity B. Black hair C. Lack of appendix D. None of these

Might be helpful to transcribe to make m. RNA codons…

Well, how could we shorten the protein? ? m. RNA: A U G - G C U - G G C - U G G - A A U

Substitute G for A DNA has to be “T” T m. RNA: A U G - G C U - G G C - U G G - A A U A

m. RNA: A U G - G C U - G G C - U G G - A A U

m. RNA: A U G - G C U - G G C - U G G - A A U

Which person on the pedigree could not pass the allele for sickle cell disease to his/her offspring? A. V B. X C. Y D. Z

Genetics In the genetic pedigree, person U and her husband are considering having another child. What is the percent chance that this child will develop sickle cell disease? A. 25% B. 50% C. 75% D. 100%

Draw a Punnett square or comparable diagram for the couple in the first generation of the pedigree. Use B to represent the allele for normal red blood cells and b to represent the allele for sickle cell disease. How do the couple’s actual children compare to the expected results shown in your Punnett square? Respond in the space provided in your Answer Document. (4 points)

1

The theory of evolution predicts that A. changes in species will take place at a predictable pace. B. alleles that improve survival will increase in frequency within a population. C. animals will become extinct if the environment changes. D. the organisms that produce the most offspring will be the ones to survive.

The use of antibiotics over the last sixty-five years has resulted in a drastic increase in populations of bacteria that are resistant to many antibiotics. The most probable cause of this change in bacterial populations is that A. antibiotics select for bacteria that have a degree of resistance, and against those that don't. B. sanitary conditions have declined over the last sixty-five years. C. the bacteria needed to develop resistance to antibiotics in order to survive. D. genetic engineering has released "super bugs" that cannot be killed by antibiotics.