EXAM 1 REVIEW (Unit 4) Flashcards
Who discovered the DNA double Helix and X-ray diffraction?
Rosalind Franklin
DNA uncoiled is called
chromatin
Chromatin is __________ DNA
compacted
Chromatin is composed of DNA wound around _______
protein
DNA is made from a _______________
pair of nucleotides
What does a nucleotide consist of?
- Base (G,C,A,T)
- Phosphate
- Sugar (deoxyribose)
______ serves as code for amino acids
DNA
Put a bunch of amino acids together and you get a _________
polypeptide
what is a genome?
all the genes of one person (humans have estimated 35,000 genes)
DNA never leaves the _________
nucleus
the library of information stored in DNA can only be copied. This is done by _______
m-RNA
protein is created by this pathway: __________
DNA to RNA to protein
genetic information flows only in one direction: DNA to RNA to PROTEIN. this is called _____________
central dogma
Genes control the production of _________
proteins
what is t-RNA?
transfer RNA.
-it looks like a big “T” with three bases called an anticodon
what is m-RNA?
Messanger RNA
- looks like a single ribbon (single helix)
-three bases attached are called a codon
what is r-RNA?
Ribosomal RNA.
-its two proteins combined together
-looks like a fist with the other hand wrapped around it
Transcription occurs in the _______
nucleus
______ transcribes DNA into its own code
m_RNA
in protein synthesis, transcription =
DNA transcribed to m-RNA
in protein synthesis, translation =
m-RNA translated by t-RNA on rough ER into a protein
ribosomes are also called _______
r-RNA
what comes first? transcription or translation?
transcription
what do enzymes do?
speed body reactions and are proteins
what happens in an enzyme reaction?
the enzyme assists in the reaction but is not used up
enzyme activity can be controlled by ________ (pHIT)
pH, inhibitors, and temperature (pHIT)
What are the three main phases in the cell cycle?
Interphase, mitosis, and cytokinesis
What are the 3 stages in interphase?
G1 phase (first growth)
S phase (synthesis)
G2 phase (second growth)
Is mitosis a part of interphase?
No, it is its own phase
is cytokinesis part of interphase or mitosis?
no
Mitosis is nuclear division and consists of four phases: _________
-Prophase
-Metaphase
-Anaphase
-Telophase
what is a genotype?
your genetic makeup
what is the outward expression of the gene? (like a photo)
Phenotype
when you have two identical alleles, or the same trait (PP or pp) what is it called?
homozygous
when you have different alleles (Pp) what is this called?
heterozygous
what causes death and is usually homozygous recessive?
lethal allele (or the lethal gene)
What is a helpful way to determine genotype?
the Punnett square
what are the three variations on inheritance?
Codominance, Incomplete dominance, and polygenic inheritance
Name the variation on inheritance:____________
-Both heterozygous alleles are equally dominant
- example: sickle cell anemia
codominance
Name the variation on inheritance: _________
- Both heterozygous alleles are expressed incompletely (not equally)
- a _____ and ______ flowers create a pINk flower
incomplete dominance
Name the variation of inheritance:
-continuous gradation of gene expression
- eye color and kids skin color of dark and light skinned parents
Polygenic inheritance
Polygenic Inheritance: Genes at two or more loci, or even different chromosomes contribute to a _____________
single phenotypic trait (eye and skin color)
What is sickle-cell disease?
-A hereditary hemoglobin defect
-effects mostly those of African decent
-shortened life span
