Biology Final

How long are DNA strands

6 feet and found in the nucleolus

What is the back bone of DNA

2 deoxyribose

How are bases held together

H-bonds

What bases line up

A-T C-G

Double Helix

Shape of DNA

Phases of Mitosis

prophase, metaphase, anaphase, telophase

Centrioles

Cell organelle that aids in cell division in animal cells only

Prophase

Chromatin condenses into chromosomes and Nucleolus disappears.

Metaphase

chromosomes line up along metaphase plate

Anaphase

Chromosomes break at centrosomes and sister chromatids move to opposite ends of the cell

Telophase and Cytokinesis

Nuclear membrane reforms and nucleoli reappear and chromosomes unwind into chromatin.

What cells do not preform mitosis

Sex Cells

Which cell splits from the inside

Plant cell

telophase under microscope

Which cell forms a cleavage and splits from the outside

Animal cell

anaphase under microscope

metaphase under microscope

prophase under microscope

Base parring

(A-T C-G) This guarantees that a copied strand of DNA always end up being the same as the original.

DNA structure

2 deoxyribose (sugar) backbone strandsBases held together by \n hydrogen bondsDNA shape is a double helix

How is DNA fit in a Chromosome

DNA wraps around a Histone to from a Nucleosome Nucleosomes come together to form Chromatine Chromatine then from loops The Chromatine loops condense to form a Chromosome

Helicase

* "Unzips" or unwinds the DNA double helix.


* Binds at the location called the replication fork
* Exposes the leading strand to the next enzyme
* Separates bases from each other

DNA Polymerase

* Synthesizes free nucleotides onto the template DNA
* Matches the right nucleotide with the exposed bases


* Creates the complementary strand

DNA Ligase

* An enzyme that puts things together


* Glues together Okazaki fragments after matching

Primase

* Enzyme that makes a primer
* The primer is the starting point for polymerase on the lagging strand

Leading strand

replicated (copied) in 3'-5' directioncopied straight off, no fragments made.

Lagging strand

* replicated in 5'-3' direction


* replicated in small pieces, known as Okazaki fragments, starting at a primer
* The polymerase has to jump back and make a small section
* Ligase glues the Okazaki fragments together

Prophase I

* The DNA is already replicated forming two pairs of chromosomes
* The homologous sister chromatids pair up 2 and 2 Chromosomes form tetrad
* Sometimes parts of the chromosomes are exchanged between the maternal and paternal chromosomes: crossing over or recombination
* In meiosis

tetrad

two homologous chromosomes that have each already replicated into a pair of sister chromatids

Metaphase I

The chromosomes are moved to the metaphase plate (the middle) they line up randomly In meiosis

Anaphase I

* The paired homologous chromosomes start to separate from each other
* The whole sister chromatid is being moved to either pole
* Pulled apart by the mitotic spindle
* In meiosis

Telophase I

* Cell starts cytokinesis, dividing the cells completely
* The cells are now haploid
* In meiosis

Haploid

having a single set of unpaired chromosomes.

Diploid

containing two complete sets of chromosomes, one from each parent

Prophase II

* Very short phase
* Centrioles start migrating
* Nucleolus dissolves
* Mitotic spindle forms
* In meiosis

Metaphase II

* Sister chromatids line up at metaphase plate
* In a line this time
* Spindle fibers attach to the centromere (middle of chromatid)
* In meiosis

Anaphase II

* Sister chromatids are being pulled to opposite sides of the cell
* Sister chromatids break down the middle
* Chromatids become separate chromosomes
* In meiosis

Telophase II

* The chromosomes have completely moved to their cells
* Membrane forms around each set of chromosomes
* The cells bud off to become individual haploid cells
* In meiosis

cytokinesis

bringing about the separation into two daughter cells

Transcription

The DNA sequence/gene is copied, substituting T for U

Translation

The mRNA sequence is matched in the ribosome with tRNA carrying an amino acid. Bases are read as triplets.

mRNA/Messenger RNA

The copy of the gene, produced/found in the nucleus, carries protein information from the DNA

tRNA/Transfer RNA

The link between mRNA and amino acids, carried one amino acid, found in cytoplasm

rRNA/Ribosomal RNA

Found in the ribosome, part of the ribosome's structure, It ensures the proper alignment of the mRNA

Introns

a segment of a DNA or RNA molecule which does not code for proteins and interrupts the sequence of genes.

exons

a segment of a DNA or RNA molecule containing information coding for a protein

What happens before the RNA goes to the ribosome

Introns are being spliced out, exons are expressed so they are kept.

Alternative splicing

Gives a single gene an option to make several different proteins.

Capping

addition of modified guanine, protects from digestive enzymes, helps attach to the ribosome

Tailing

addition of 50-300 adenine nucleotides at the tail end, enzymes will "nibble" at this end.

how is the mRNA protected from digestive enzymes

Capping and Tailing

Order of RNA-coding sequence

Transcription, RNA processing, Translation

Initiation

tRNA starts the coding based on the start codon - AUG

Elongation

Amino acids are joined together one-by-one with covalent bonds

Termination

A stop signal is reached on the mRNA and the new polypeptide chain detaches.

Codon

The triplet of bases on the mRNA that correspond to a particular amino acid

Anti-codon

The complimentary triplet of bases on tRNA that brings a specific amino acid to the ribosome

Promoter sequence

non-coding DNA, longer"Shows" where transcription for RNA startsVery often known as the TATA boxLocated 25-35 bases away from the start of the actual gene

Enhancer sequence

non-coding DNA, shorterEnhances the rate of transcription \= makes transcription faster

Chromosome

condensed DNA, containing genetic information

Gene

a specific sequence of DNA, containing instructions for a specific trait/protein

Genome

The complete genetic information of an organism

Allele

a variation of a gene, ex: red or white flowers

Monohybrid cross

a cross on one trait only

Homozygous

two of the same alleles of the same gene ex: red+red

Heterozygous

two different alleles of the same gene ex: red+white

Dominant allele

the allele is "stronger" and will show

Recessive allele

the allele is "weaker" and will not show unless there is two of the same allele

Phenotype

observable characteristics, or protein made

Genotype

the genetic information i.e which alleles are present

Complete dominance

When an allele completely dominates another

Dihybrid crosses

When you look at two traits at the same time EX: flower color and pea color 4x4 Punnett square

Incomplete dominance

traits are somewhere in between the two possible genotypes.

Co-dominance

When to alleles are expressed at the same time, since the alleles are equally dominant or "strong

Type A Blood

IAIA or IAi

Type B Blood

IB IB or IB i

Type AB Blood

IA IB

Type O Blood

i i

Sex-linked traits

genes found on the sex chromosomes, X and Y

How are sex-linked traits written in Punnett squares

Males are X^ and Y females have X^X^

Point mutation

Change in one single base in the DNA sequenceAlso known as single substitution mutation

Substitution

Can be a single point mutationCan be several bases

Inversion

when a part/segment of a mutation is reversed

Insertion

When a new base or segment is added inCauses a frameshift, which makes the protein different

Deletion

When a base or a segment is removedCauses a frameshift

Silent mutation

No change in the amino acids/proteins being produced

Missense mutation

The amino acid sequence changes

Nonsense mutation

Creates a STOP in the amino acid sequence, which gives a change in function

Frameshift mutations

Changes where the reading of the code starts and ends and can change the amino acid chain/protein dramatically

Survival of the fittest

meaning the most fit for the circumstance will survive

where did Charles Darwin's dad send him to school

sent him to med school and he flunked out

Boat the Charles Darwin joined to study the world

HMS Beagle and travelled around the world for 5 years, 1831-1836

What book did Charles Darwin write releasing his theory

On the Origin of Species

Species

Two individuals who can mate and produce viable/fertile offspring are the same species

Cadigory's all species fall under

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species (Dead King Philip Came Over For Good Soup)

What is needed for evolution?

* Genetic variation
* Sexual reproduction
* Overproduction of offspring
* Competition for resources: food, shelter, mates, space/territory, water
* Adaptation
* Environmental pressures: climate, weather, competition, mutations
* TIME

descent with modification

the idea that species change over time, give rise to new species, and share a common ancestor.

Signs/evidence of evolution

* Fossils
* Similarities in anatomy
* Biogeography (the spread of species)
* Organism's' ability to adapt to their environment

Fossils

* Rests or "prints" of previously living organisms
* Some have been packed in material that has hardened over time
* Some are prints in sedimentary rock or volcanic rock
* can also be found in ice and amber

Rudimentary organs

organs that seem to have lost its function