unit 5 Flashcards
3 parts of the cell cycle
interphase, mitosis, cytokinesis
chromosomes
structures that contain the genetic material, condensed form of DNA
chromatin
relaxed form of DNA in the cells nucleus
mitosis
cells replicated genetic material separates, cell prepares to split into two daughter cells (during cytokinesis)
key activity of mitosis
accurate separation of the cells replicated DNA
prophase
first and longest stage of mitosis, nuclear membrane breaks down, nucleolus disappears, cells chromatin condenses into chromosomes
sister chromatids
structures that have identical copies of DNA, attached by centromere
centromere
links a pair of sister chromatids during mitosis
spindle apparatus
formed with spindle fibers, centrioles, and aster fibers as prophase continues, attaches to each of the sister chromatids before mitosis
metaphase
second and shortest phase, sister chromatids are pulled along the spindle apparatus toward the center of the cell, line up in the middle of the cell forming a metaphase plate
anaphase
sister chromatids are pulled apart, sister chromatids separate, they are now chromosomes and move toward the poles of the cell
telophase
chromosomes arrive at the poles and begin to decondense, two new nuclear membranes begin to form and the nucleoli reappear, spindle apparatus disassembles
cytokinesis
two daughter nuclei have formed, animal cells form cleavage furrow, plant cells form cell plate
cancer
uncontrolled growth and division of cells
mutations
cause the growth and division of cancer cells
benign tumors
a lump of abnormal cells remain at the original site
malignant tumors
invade surrounding tissues and can metastasize, may form secondary tumors in other parts of the body
what does DNA stand for
deoxyribonucleic acid
dna codes for
proteins
dna is found in
the nucleus
proteins are needed in
immune system, hair/skin/nails, muscles, nervous sytem, enzymes
nucleotide
monomer of nucleic acids that consists of 5 carbon sugar, phosphate group, and a nitrogenous base
four nitrogenous bases for DNA
adenine, guanine, cytosine, thymine
four nitrogenous bases for RNA
adenine, guanine, cytosine, uracil
dna is often compared to a
twisted ladder or double helix
rails of the ladder of DNA are represented by
alternating deoxyribose sugar and phosphate
steps of the ladder of DNA are represented by
the pairs of bases (C-G and T-A)
purine base
always binds to a pyrimidine base
purine bases consist of
adenine and guanine
pyrimidine bases consist of
cytosine, thymine, uracil
sugar and phosphate make up the backbone of DNA and are joined by
covalent bonds
nitrogen bases will join the complementary stand with a
hydrogen bond
semiconservative replication
parental strands of DNA separate, serve as templates, and produce DNA molecules that have one old strand and one new one
unwinding
pairing
joining
DNA helicase
unwinds the helix, breaking the hydrogen bonds between bases
single-strand binding proteins
keep the DNA strands separate during replication
primase
adds a short segment of RNA primer on each DNA strand
DNA polymerase
adds appropriate nucleotides to the new DNA strand at the 3’ end
leading strand
built continuously
lagging strand
built discontinuously in small segments called okazaki fragments
DN polymerase removes
the RNA primer and fills in the place with DNA nucleotides
DNA ligase
links the two DNA strands together
DNA replication in eukaryotes
DNA unwinds in multiple areas
DNA replication in prokaryotes
circular DNA strand is opened at one origin
biotechnology
using organisms to perform practical tasks for humans, produce a product for the betterment of humans
recombinant DNA technology
combining DNA from different sources into a single DNA molecule
action of restriction enzymes
cut DNA at specific sequences, restriction site
what can we do with biotechnology
make a genetically modified organism, ex: GMO food keeping pests and diseases out of the way
polymerase chain reaction
producing multiple copies of a DNA sample, when heated DNA will separate into two single stranded fragments
CRISPR
technology that can be used to edit genes, a way of finding a specific bit of DNA inside a cell
gel electrophoresis
dna molecules are cut with restriction enzymes , pieces are separated by size, DNA has a negative charge it will be attracted to positive end of the gel
how could you use gel electrophoresis
DNA fingerprints
what causes a mutation
an error that results in a change in the DNA sequence
gregor mendel
looked for the molecule involved in inheritance
frederick griffith
performed experiment with a bacteria in 1928, was the first major experiment searching for genetic material
oswald avery
in 1931 he identified that DNA was the molecule that transformed the R strain of the bacteria into the S strain
alfred hershey and martha chase
in 1952 they published the results of their experiment with bacteriophages, a type of virus that infects bacteria
what did hershey and chase use to trace bacteriophage DNA and protein
radioactive labeling
conclusion of the experiment of hershey and chase
only radioactive phosphorus, not sulfur, was detected inside the infected bacterial cells
point mutation
results in a change from one nucleotide to another, either no issue or big issue
types of point mutations
missense, nonsense, silent
missense
has changed one nucleotide in the sequence, amino acid sequence will change, ex: sickle cell anemia is caused by a missense mutation that doesn’t allow hemoglobin protein to fold right
nonsense
has changed on nucleotide in the sequence to a stop codon, the protein will stop before its complete, ex: thalassemia (a milder form of sickle cell anemia)
silent
has changed one nucleotide in the sequence, no change in the resulting amino acid or protein
insertion (frameshift mutation)
a nucleotide is inserted into the stand, changes all the remaining amino acids and the resulting protein !
deletion (frameshift mutation)
a single nucleotide has been deleted, changes all the remaining amino acids and the resulting protein !
mitosis type of cells
somatic (body cells)
meiosis type of cells
sex cellls
how many cell divisions are in mitosis
1
how many cell divisions are in meiosis
2
products of mitosis
2 diploid (2n) daughter cells
products of meiosis
4 haploid (n) daughter cells
are daughter cells in mitosis identical or unique
identical
are daughter cells in meiosis identical or unique
unique
how many chromosomes are in human cells (mitosis)
46
how many chromosomes are in human cells (meiosis)
23
what did rosalind franklin accomplish?
what did watson & crick accomplish?
in 1953 they discovered that the shape of a DNA molecule is a double helix
what is tDNA?
RNA molecule that serves as an adaptor between the mRNA and the growing chain of amino acids that make up a protein
what is mRNA?
genetic material that tells your body how to make proteins, the messenger
what is a codon?
a sequence of three nucleotides that correspond to an amino acid
what is an anticodon?
a sequence of three nucleotides that are complementary to codons
