Reporting Category 2

Organization of Living Systems

TEK 6A Identify components of DNA, and describe

how information for specifying the traits of an organism is carried in the DNA

General Information Purpose: Genetic information is stored in DNA Location: nucleus of living cells Discovery: Watson and Crick discovered the

3D shape of DNA, now called the Double Helix Structure:

Sugar phosphate backbone Nucleotides (nitrogenous bases)

Matching and Bonding Matching base pairs:

A-T C-G

Bonds that hold DNA together: Backbone: connected by

covalent bonds Bases: connected by hydrogen

bonds

Example Questions1. Why will knowledge of the human genome enable scientists to better understand proteins involved in human diseases?A: DNA contains the information used to make proteins

2. A particular strand of DNA has the base sequence ATT-CCG. What is the base sequence of the complimentary strand?A:TAA-GGC

TEK 6E Identify and illustrate changes in DNA and evaluate the significance of these changes

What causes mutations?1. DNA damage from environmental

agents such as ultraviolet light(sunshine), nuclear radiation or certain chemicals

2. Mistakes that occur when a cell copies its DNA in preparation for cell division

Types of Mutations1. Point mutation-change to one base in a gene

sequence

2. Inversion- an entire section of DNA is reversed

Types of Mutations3. Frame shift- one or more bases are inserted

or deleted, like adding or removing letters in a sentence

a. insertion-adding one or more bases to a gene sequence

b. deletion-when one or more bases to a gene sequence are deleted (or missing)

Example Question

TEK 6FPredict possible outcomes of various genetic combinations such as monohybrid crosses, dihybrid crosses and Non-Mendelian inheritance

Important Vocabulary Dominant- an allele that is expressed or

shown in the phenotype; it masks or hides recessive allele traits

Recessive- an allele that is not expressed or shown in the phenotype because it is hidden by the dominant allele

Homozygous- when an organism has the same alleles for a trait (can be dominant or recessive)

Heterozygous- when an organism has two different alleles for the same trait (dominant trait is shown)

Genotype vs. Phenotype

Genotype Phenotype Refers to the two

alleles an individual has for a specific trait

Refers to the physical appearance of the individual

Mendelian vs. Non-Mendelian Genetics

Mendelian Non-Mendelian Law of

Segregation Each individual

has a pair of alleles for each trait

Alleles segregate during gamete formation(egg and sperm)

Fertilization gives the offspring two alleles

Incomplete dominance If an organism is

heterozygous for a trait the phenotype is a blend of the two allele types

Codominance An organism that

has both alleles of a gene displays both phenotypes at the same time

Examples of Non-Mendelian Genetics

Monohybrid and Dihybrid crosses

Monohybrid Dihybrid After completing the

punnett square answer the questions

1. what percent of the offspring will be short?

2. what percent will be tall?

What is the genotypic ratio for DdRr?

More Dihybrid Practice: AABb x AaBb

TEK 6B Recognize that components that make up

the genetic code are common to all organisms

The Genetic Code In all living organisms, the

instructions for reproducing and operating the individual is encoded in DNA

The genetic code is universal This leads scientists to believe

organisms have a common ancestor

The Genetic Code How many different

codons code for Leucine (Leu)?

6 What does that lead

you to believe about the genetic code and mutations to DNA?

That if one base pair changes, the mutation may have no effect if you still end up with the same amino acid

TEK 6C Explain the purpose and process of

transcription and translation using models of DNA and RNA

Central Dogma Thesis that information flows from DNA to

RNA to protein

Protein Synthesis Protein Synthesis is divided into two processes: Transcription and Translation Transcription

A section of DNA is copied into mRNA; this takes place in the nucleus

Remember: RNA has U instead of T Translation

mRNA codons are translated into amino acids with the help of tRNA.

A ribosome attaches the amino acids to form the protein

This takes place in the cytoplasm

Transcription and Translation

TEK 6DRecognize that gene expression is a regulated process express = “turn on” Repress = “turn off”

Environmental Factors The expression of genes in an

organism can be influenced by the environment

Factors include: Gender Chemicals Temperature light

Gene Regulation Gene regulation in eukaryotes takes

place during each phase of the process Chromatin Remodeling-the region of the

chromosome must be open in order for the gene to be accessed

Transcriptional Control-most common type; can turn on or off mRNA

Translational Control-regulation of the rate; make an inactive protein active

TEK 6GRecognize the significance of meiosis to sexual reproduction

Chromosome Structure Chromosome: a single piece of

coiled DNA containing many genes

Homologous Chromosome: each chromosome has a match. This is why you have 46(even number). You get 23 from each parent

Sex Chromosome: X and Y; determine the sex of the organism; XX= female, XY = male

Process of MeiosisMeiosis: the production of haploid cells with unpaired chromosomes

Broken down into two phases: Meiosis I Meiosis II

Key points of meiosis The process results in 4 daughter cells Daughter cells are haploid(23

chromosomes) Daughter cells have unique

combinations of chromosomes Daughter cells do not have homologous

pairs Meiosis creates gametes(sperm and

eggs) Meiosis ensures variability in offspring

Independent Assortment and Crossing over Independent assortment: alleles for a

particular phenotype determine what characteristic an organism will express When alleles separate during metaphase I it

is random which cell each allele ends up in Crossing over:The exchange of genes

between homologous chromosomes, resulting in a mixture of parental characteristics in offspring. This increases genetic variability

Mitosis vs. Meiosis

TEK 6HDescribe how techniques such as DNA fingerprinting, genetic modifications, and chromosomal analysis are used to study the genomes of organisms

Human Genome Project Completed in 2003 13 year project Goals:

Identify all the 20,000-25,000 genes in human DNA

Use data to improve medical technologies and treatments

Address ethical, legal and social issues

Manipulating DNA Genetic Engineering is the process of

reading and changing DNA sequences in an organism

1. DNA extraction 2. Cutting and Labeling DNA 3. Separating DNA 4. Reading the DNA sequence 5. Making copies(PCR)

Uses of Gel Electrophoresis DNA Fingerprinting

Paternity tests, crime scene samples Gel electrophoresis is used to separate the

DNA sample into pieces The position and length of bands are

unique like a fingerprint Material you can get samples from:

Blood Hair Saliva Semen Body tissue cells

Gel Electrophoresis