Bio Exam Two Study Prep
DNA Replication ensures
all somatic cells carry the same genetic information
Gene Expression
THE PROCESS BY WHICH GENETIC INFO FLOWS FROM GENES TO PROTEIN
Metaphase 1
Tetrads are aligned along the cell equator
Metaphase 2
The (still duplicated) chromosomes are aligned midway between poles Haploid
Autosome
The same in male and females First 22 chromosomes
Phases of Mitosis
Prophase Metaphase Anaphase Telophase
Only 3% code for
Protein (Others have no effect)
Natural Selection
Variation Heritability Unequal Production
DNA - Basis of life unity
Variations in crossing over and reproducation is the foundation of life's diversity
DNA Technology Applications
- Forensics - Medical and industrial products - GMO's for agriculture - Human family and evolutionary relationships - Many areas of biological research
Viruses are
- Not considered alive - Not cellular - Cannot reproduce on their own (Hosts cells)
Cancer Treatments
- Surgery to remove tumor - Radiation therapy (high-energy radiation) - Chemotherapy (drugs to disrupt growth)
Diploid
2 sets of chromosomes
Trisomy 21
21st chromosome with three chromosomes that results in Down syndrome
Human Chromosomes
46 chromosomes, 23 pairs, 22 autosomes, 1 sex chromosome
Genotype Ratio
9:3:3:1
Karyotype
A picture of a diploid set of chromosome
Anaphase 2
All sister chromatids sperate The (now unduplicated) chromosomes head to poles Haploid
Cytokinesis in animal cells
Cleavage Furrow
Virus
An infectious particle consisting of - Nucleic Acid - Protein coat (Cansid) - A membrane envelope - Rely on hosts cells
Haploid
An organism or cell having only one complete set of chromosomes. (Half of a diploid) Starts after telophase 1
Centromere
Area where the chromatids of a chromosome are attached
Causes of Cancer
Caused by lost control of the cell cycle at checkpoints
Cytokinesis in plant cells
Cell Plate
Gregor Mendel (1822-1884)
Austrian Monk - Scientists Used peas and flowers to observe genetic inheritance
Mutations
Can form in any cell Those in gametes can be passed to offspring May have a harmful or lethal outcome Some give rise to variation in trait (Basis for evolution)
Cancer and Tumors
Cancer cells form tumors - Abnormally growing masses of body cells
Malignant Tumors - Cancer
Cells Spread
Benign Tumors
Cells do not spread
Prophase 1
Chromosomes Condense Homologous chromosomes come together by synapsis Crossing over occurs
Telophase 2
Chromosomes arrive at poles Nuclear envelopes form Haploid
Telophase
Chromosomes arrive at spindle poles and decondense, nuclei form, and spindle disappears
Prophase
Chromosomes become visable, nuclear envelop dissolves, spindle forms
Prophase 2
Chromosomes condense The nuclear envelope breaks up haploid
Metaphase
Chromosomes line up between spindle poles
AUG
Codes for methionine signals for the start of transcription
Transgenic Organism
Contain at least one gene from another species
Transgenic organisms
Contain at least one gene from another species
Nonsense Mutation
Creates a stop codon: AGA to UGA
Interphase
DNA replication occurs
DNA Replication
DNA unzips into two parts and splits with the cell. In it's new home each side of the DNA strand attack to matching nucleotides to create 2 exact copies. It is important in puberty and other times of growth as it is the reproducing of your cells.
Gametes
Derive from germ cells: immature reproductive cells Haploid (1n)
Sex Chromosome
Differ between females and males Females - XX Males - XY
Alleles
Different forms of the same gene
Telophase 1
Duplicated chromosomes reach the poles Nuclear envelopes reform Each nucleus is now haploid
DNA polymerase
Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule
Mitosis and zygotes
Every cell in your body was produced through successive rounds of mitosis starting from the zygote
A-T
G-C
Cell devision functions in
Growth, healing/repair, development, sexual reproduction (gametes), asexual reproduction (single-celled organisms)
Anaphase 1
Homologous pairs separate and move towards opposite poles of the cell
DNA
James Watson and Francis Crick First discovered in 1869 Not understood until 1950s Rosalind Francolin made first x-ray image of DNA
Linked genes
Located near one another on the same chromosome
Reproductive Cycles
Lytic Cycle Lysogenic Cycle
Test Cross
Mating between an individual of unknown genotype and a homozygous recessive (pp) individual
Dihybrid Cross
Mating of parental varieties that differ in two characteristics (RrYy and RrYy)
DNA Technology
Modern techniques to study and manipulate genetic material
Codominence
More genotype than phenotype
Polygenic Inheritance
Multiple genes that affect one trait
Silent mutations
No effect: Changing from GAG to GAA
Pleiotropy
One gene that affects multiple traits
genetically modified organism (GMO)
Organisms contain one or more genes introduced by artificial means
GMO
Organisms containing one or more genes introduced by artificial means
Monohybrid cross
Original: Pp and Pp Produces: PP, Pp, Pp, and pp
Gel Electrophoresis
Procedure used to separate and analyze DNA fragments by placing a mixture of DNA fragments at one end of a porous gel and applying an electrical voltage to the gel
Inique Individuals
Produced by sexual reproduction
Meiosis
Produces 4 daughter cells 1 chromosome each
Missense mutation
Produces different amino acid: GGC to AGC Can be beneficial, harmful or neutral
Asexual Reproduction
Produces offspring that are identical to the "parent"
Sexual Reproduction
Produces offspring with two sets of genes from two parents Requires fertilization of an egg by sperm
Mutagenesis
Product of mutations Mutations can be used by: Error during DNA replication Mutagens (Highly radioactive or chemicals)
Most plant and animal viruses have ___ rather than DNA
RNA
Incomplete dominence
RR - red rr - White Rr - Pink
61 codons
Respond to amino acids
Frameshifts
Result from deletion or insertions Alters the reading frame Leads to change in amino acid Produces a nonfunctional polypeptide
Meiosis Errors
Result in genetic abnormalities
A pedigree
Shows the inheritance of a trait in a family through multiple generations Demonstrates dominant or recessive inheritance
Mutations in a hemoglobin amino acid cause
Sickle cell disease
Anaphase
Sister Chromatids separate and move towards opposite spindle poles
Viroids
Small, circular RNA molecules that affect plants
Biotechnology
The manipulation of organisms to make useful products
DNA is _________________ into RNA.
Transcribed
RNA is ________________ into a protein (polypeptide).
Translated
3 "stop" codons
UAA, UAG, UGA
A codon for one amino acid does not code for any other amino acid
Unambiguous
Lytic Cycle
a viral reproductive cycle in which copies of a virus are made within a host cell, which then bursts open, releasing new viruses
Lysogenic Cycle
a viral reproductive cycle in which the viral DNA is added to the host cell's DNA and is copied along with the host cell's DNA
Mutations can cause
cancer
Non disjunction
chromosomes fail to separate at anaphase producing gametes with abnormal numbers of chromosomes
Three nucleotides
codon
Recombinant DNA
formed by joining nucleotide sequences from two different sources The gene to be cloned and a vector
Zoonotic diseases
greater than 60 percent human diseases start in animals
Human Gametes
have 23 pairs of homologous chromosomes
Hold two strands of DNA together
hydrogen bonds
Human gene therapy
intended to treat disease by introducing genes into an afflicted person
Genetic Engineering
manipulation of genes for practical purposes
Gene Regulation
mechanisms that turn on certain genes while other genes remain turned off Allows for specialization of cells within the body
The genetic code is
nearly universal
Gene cloning
production of multiple identical copies of a gene
More than one codon for some amino acids
redundant
Double Helix
two strands of nucleotides wound about each other; structure of DNA
Emerging viruses
viruses new to medical scientists
