Quarter 3 Bio Review

(A v S Rep; I v A Traits; Genotypes; Types of I; Mutations; Protein Synthesis)

Asexual Reproduction *A v S Rep*

-1 parent

-identical offspring

-no sex cells

Sexual Reproduction *A v S Rep*

-2 parents

-variation offspring

-sex cells involved

Inherited Traits *A v I Traits*

-coded within genetic info

-can be passed from parent to offspring

Ex: eye color, hair color

Acquired Traits *A v I Traits*

-not coded within genetic info

-cannot be passed from parent to offspring

Ex: Dying hair, tattoo, scar

Dominant *Genotypes*

“Stronger” allele or version of the gene that masks the recessive allele

Recessive *Genotypes*

“Weaker” allele, must have 2 recessive alleles to show trait

Phenotype *Genotypes*

The physical appearance of an organism (black fur, blue eyes)

Genotype *Genotypes*

The genetic makeup of an organism. Represented by letters (BB, Hh), comes in pairs because each allele is received from each of the two parents

Heterozygous or Hybrid Genotype *Genotype*

Having two different alleles or versions of the gene

Homozygous or Pure *Genotype*

Having the same two alleles or versions of the gene

Mutation *Genotypes*

A change in an organism's DNA/ Genetic information

Variation *Genotypes*

Any differences between individuals. Ex. Black fur color vs white fur color

Allele *Genotypes*

Different forms a gene could take. Ex: brown (B) gene or blue (b) gene for eye color

Creating an Allele Key *Genotypes*

Dominant allele use a capital letter 

Recessive allele use a lower case letter

When writing genotypes use only 1 letter

Traits determined by pair of genes

Ex: B-Brown / b-blue

BB → Brown eyes   Homozygous or pure Dominant

Bb → Brown eyes    Heterozygous or hybrid

bb → blue eyes       Homozygous or pure Recessive

MUST KNOW!

How to make punnet squares and pedigrees

Complete Dominance *Types of I*

B (capital means dominant trait) b (means recessive trait), Use the same letter. 2 phenotypes, 3 genotypes

Incomplete Dominance *Types of I*

NO MORE LOWER CASE LETTERS.  3 phenotypes, 3 genotypes.  This is BLENDING.  Ex. RR= red  WW= white, RW = pink.  The hybrid is the BLEND of the other 2.

Codominance

BOTH dominant traits show up in the hybrid. You can use superscripts here. 3 phenotypes, 3 genotypes.  Ex. ROAN cows. C^RC^R = Red   C^WC^W = White   C^RC^W= Red AND White (roan).

Sickle Cell Anemia Overview *Mutations*

Hemoglobin molecules changed shape, causing blockages in blood vessels and pain.  Less oxygen delivered to organs

Mutation in DNA causes single amino acid substitution 

Inheritance pattern: codominance

Hybrids have less severe forms of malaria.  SICKLE CELL DOES NOT CAUSE MALARIA

Treatment: CRISPR Cas-9 for severe cases.  Be familiar with how Cas-9 works.  Cas-9= enzyme, CRISPR = process 

Good term *Mutations*

Mutations in gametes (sperm or egg) can be PASSED ON to future offspring while mutations in body cells do not have an effect on future offspring

Insertion *Mutation*

When you insert more bases within the DNA code. Big effects.

Deletion *Mutation*

When you remove bases within the DNA code. Big effects.

Substitution *Mutation*

When you replace one of the bases within the DNA code. Not as big effects.

DNA *Protein Synthesis*

Structure: Double helix (looks like a ladder)

Monomer: nucleotide (phosphate, deoxyribose sugar, nitrogen base (A, T, C, or G)

Location: Nucleus (chromosomes are made up of DNA

Function: provides genetic information for living organisms and codes for different amino acids that get strung together to make proteins

Base Pairing Rule:

Adenine-Thymine  

Cytosine-Guanine

The SAME DNA is found in EACH cell (except sperm or egg, they have half the information).

Coding DNA *Mutations*

-They have a DNA sequence to encode for proteins

-The coding sequence have exons

-They are approximately 1% of our total genome

-They encode proteins that have regulatory, structural, as well as functional importance

Non-coding DNA *Mutations*

-These DNA sequences do not encode for protein

-It has regulatory elements, introns, repeating sequences, pseudogenes, and telomeres

-They form around 99% of our genome

-They control and regulate gene activity

Genes *Mutations*

Segments of DNA that code for protein

Transcription *Mutations*

First part of protein synthesis occurs in the nucleus.  DNA is “read” and TRANSCRIPTION onto messenger RNA (mRNA). mRNA is single stranded and can leave the nucleus.

Example:

DNA sequence:

• ATT CCG TAT

  • mRNA sequence: UAA    GGC   AUA

    **Notice: When translating to mRNA, the Thymines are changed to Uracil (U).

Translation *Mutations*

• Second part of protein synthesis: mRNA travels through the cytoplasm to the ribosomes where proteins are physically put together.  With the help of tRNA (transfer RNA) the amino acids are physically moved and attached to one another at the direction of the mRNA.  This is called TRANSLATION.

  • mRNA sequence:  UUA     GGC       AUA

  • Each group of 3 nucleotides is called a CODON

  • ANTICODON complementary bases on tRNA

  • Using the chart below, find the amino acid coded for by the mRNA

  • UUA = Leu          GGC= Gly       AUA=Ile

  • The sequence of amino acids of any protein, and therefore its overall structure is determined by the gene's DNA sequence in the nucleus.