Potentially hazardous mutations would accumulate in the cell.
Several enzymes work together to repair defects in DNA caused by replication errors or environmental damage. One enzyme cuts out the damaged nucleotide section and other enzymes replace the damaged section with the correct sequence. What would MOST likely
It determines the type of protein being produced.
What is the significance of the sequence of nucleotides?
It would change the sequence of DNA nucleotides in affected cells.
How would overexposure to X-rays affect most animal cells?
The gene coding for the protein producing yellow coloring has been mutated.
A plate containing yellow colonies of bacteria is exposed to radiation. The next day the colonies are larger; some colonies have yellow centers and white edges. What has happened?
DNA
Every copy of a particular protein manufactured by a cell shows the same incorrect amino acid at the same point in its structure. According to the central dogma of molecular biology, in which structure does this error originate?
addition
Consider the DNA sequence below:
TAC GCA CTG
The sequence was exposed to radiation and formed this mutated sequence:
TAC GCA GTA CTG
A U C G
Which best represents the sequence of bases on mRNA?
It contains thymine
Dr. Tanaka discovered a new virus. The virus has a single strand of a nucleic acid, but she does not know if it is DNA or RNA. After running tests, she concludes that it is DNA. Which of the following would lead her to that conclusion?
Asn Thr Arg Ile
A DNA strand has a nucleotide sequence of TTA TGC TCC TAA for a gene segment.
What is the amino acid sequence of the complementary mRNA strand of this DNA strand ?
nucleus and ribosome
What two organelles are involved in protein synthesis?
TAT CGC CGG
Which is the DNA complement of ATA GCG GCC?
DNA determines the amino acid sequence of each protein.
What is the relationship between an organism's DNA and protein produced?
mRNA
Which is made during transcription?
substitution (point mutation)
Which type of mutation is shown in the following DNA sequence?
ACTGCA ? AGTGCA
mRNA brings the code of DNA to the ribosome where it is used to construct a protein
Which best describes the role of mRNA in protein synthesis?
alternating sugars and phosphates
DNA is a spiral ladder-shaped structure with the sides of the ladder representing which components?
The two strands of DNA need to be separated so new bases can pair with each template strand.
Why does DNA need to be "unzipped" before it can be replicated?
ATA GGG CTA
Which complementary base sequence can be produced during DNA replication?
a single nitrogen base, a sugar, and a phosphate
Which are the basic units of a DNA nucleotide?
adenine-thymine
Which nitrogen bases of DNA are complementary?
So genetic information is correctly passed on to govern the cellular processes in the new daughter cells.
Why is it important for DNA to be duplicated exactly before a cell divides?
substitution
Which mutation in DNA affects only one nucleotide in a sequence?
differentiation
Which best accounts for the variety of cells within our bodies?
The cancerous cells continue to grow even after receiving a chemical signal to stop.
Which is a possible explanation for cell growth caused by abnormal or uncontrolled cell division?
Each cell contains a complete copy of the organism's DNA, and a specific set of DNA is activated for cell specialization.
Which best describes cell specialization in humans?
creation of new tissues
What is a potential use of embryonic stem cells?
stem cells
Which cell types can differentiate into a variety of cells?
tissue
Below is a flow chart of the hierarchy of cell organization in the human body.
cells-?-organs-organ system
What term should be placed between the terms cells and organs?
They are long and have branches that allow them to connect to other cells.
How are nerve cells adapted to perform their primary function?
Transcription of different genes leads to the synthesis of different proteins in the two cell types.
What causes DNA instructions to make a muscle cell instead of a nerve cell?
cells specialized in function leads to specialized cells, tissues, and organs
Which best describes cell differentiation?
Animal cells have flexible membranes and plant cells develop a cell plate
Which is an accurate comparison of cytokinesis in animal and plant cells?
Chromosomes must be copied.
At the end of the mitotic cell cycle, a cell divides into two cells. What must happen before the cell divides?
prophase, metaphase, anaphase, telophase
Which is the correct order of cell mitosis?
haploid
Meiosis contributes to the process of reproduction by producing what type of cell?
50
If a daughter cell has 50 chromosomes after mitosis, how many chromosomes were in the parent cell?
the cell grows, metabolizes, and synthesizes more genetic material
Why is interphase the longest stage of the cell cycle?
A disruption in the cell cycle has taken place.
Which factor best explains how many diseases, such as cancer, are formed within the body?
mitosis
Which process produces two somatic cells?
So the duplicated chromosomes can be separated into new cells.
Which explains why the nuclear membrane breaks down during mitosis?
loosely wrapped around proteins forming chromatin
What form does the DNA of a cell have during interphase?
exposure to ultraviolet rays
A patient visits the doctor for a checkup and is diagnosed with skin cancer. Which is the most likely cause of this disease?
interphase
What is the longest stage of the cell cycle?
they ensure the DNA and organelles are properly replicated
Cells do not begin mitosis without passing several key checkpoints in interphase. Why are these checkpoints necessary?
cytokinesis
What process involves the division of the cytoplasm?
It would inhibit prophase.
Vincristine is a chemotherapeutic drug used to treat cancer by damaging mitotic spindles. Which best explains why the drug could be fatal to a cell?
During differentiation, certain genes are activated to produce proteins that enable specific functions.
Myosin is plentiful in muscle cells, but is not found at all in lens cells. Lens cells contain large amounts of crystallins, which are not found in muscle cells. Why do some proteins appear in one type of cell but not in another?
Transport oxygen throughout the body
Red blood cells have a biconcave structure in order to do what particular function?
mitosis
Last year Steve was shorter than his brother. This year Steve is taller than his brother. What cell process is directly responsible for Steve's growth?
Meiosis results in 4 haploid cells, and mitosis results in 2 diploid cells.
Which best represents one fundamental difference between the processes of mitosis and meiosis?
Nucleotide.
What are the monomers of DNA?
DNA contains information that directs protein synthesis in which it is important in mitosis and meiosis.
What is the function of DNA?
DNA polymerase "unzips" the DNA strands by breaking the hydrogen bonds between each base pair. The two strands are used as templates for the attachment of complimentary bases. Two new identical DNA molecules are formed. DNA polymerase proofreads the new s
Summarize the process of DNA replication.
DNA base pairings: A - T, C - G
RNA base pairings: U - T, C - G
How does the base pairing of DNA compare with base pairing of RNA?
points: insertions, deletions, and substitution
Frameshift: insertion and deletion
What are the 2 types of gene mutations. Give an example of each.
Gene and chromosomal.
What are the two types of mutations?
Genetic variation
What is the evolutionary advantage of meiosis?
Contains both sets of homologous chromosomes
Define diploid
Contains a single set of chromosomes
define haploid
A set of chromosomes from dad and a set of chromosomes for mom.
Define a homologous chromosome.
The process of cell division involved in sexual reproduction
What is meiosis?
G1: cell grows and develops
S: DNA synthesis (replication)
G2: cell prepares for division
Describe the events that occur during interphase.
Cell pinches into two identical cells.
Describe the events that occur during cytokinesis.
Interphase, mitosis and cytokinesis.
List the three stages of the cell cycle.
Mitosis: division of the nucleus
Cytokinesis: division of cytoplasm into 2 daughter cells
Contrast mitosis and cytokinesis.
cancer
Describe the possible results of uncontrolled cell growth.
the volume starts to grow faster than the surface area and the cell is forced to divide or burst. As a cell gets bigger, the outside is unable to keep up with the inside, because the inside grows a faster rate than the outside is surface-to-volume ratio.
Explain why cells cannot simply grow by increasing in size. Explain the term surface-to-volume ratio.
(messenger)complimentary to one DNA strand
what is mRNA
(transfer): carries the amino acid in translation
what is tRNA
(ribosomal): a ribosome
what is rRNA
cells differentiate into many types of cells, that are different from the embryonic cell
What happens during the development of an organism?
unspecialized cells from whcih differentiated cells develop
Stem cells
the pluripotent cells found in the early embryo, that produce all cells in the human body.
Embryonic Stem Cells
Production of wrong enzymes
What is uncontrolled cell division (Cancer) can be caused by.
Mutations (Mistakes) in genes that control enzyme production
Causes of cancer
Smoking, Radiation exposure and viral infection
Some defects are caused by
�nuclear membrane disappears
�chromosomes become visible
�centrioles appear and move to the opposite poles
�spindle fibers form and elongate
prophase
�spindle fibers attach to the centromere
�spindle fibers "pull" at the chromatids
�chromatids "meet in the middle
metaphase
metaphase
the shortest phase of mitosis
�begins as soon as chromatids break
�chromosomes move towards the opposite poles
anaphase
�chromosomes reach the opposite poles
�nuclear membrane re-forms
�centrioles and spindle fibers disappear
�cytokinesis begins here
telophase
<the cell breaks to form two daughter cells
�different in plant and animal cells
cytokinesis
sections of a chromosome that codes a specific trait
genes
chromatid
copies of the chromosome
centromere
where the sister chromatids join
a repeated pattern of growth and division in eukaryotic cells
�consists of 3 phases
cell cycle
majority of the cell cycle
�at the end, the cell has 2 full sets of DNA and is ready to begin the division process
interphase
which part of the cell that is activated
differentiation of a cell depends on
where chromosomes start to pull apart
anaphase
baby cells with clear wall between
telophase
chromosomes lined up in middle
metaphase
where chromosomes are unwinding (fuzzy circle)
interphase
where individual threads can be seen
prophase
�do not listen to signals or checkpoints
�are constantly growing and do not die naturally
�grow until they take over the organ(s)
�body usually senses change and tries to fix the DNA or the immune system destroys mutated cells
cancer cells
g1: cell grows/lives
g2: cell prepares for division
difference between g1 and g2
a dna component, a chemical (purine) that is always combined with a thymine (pyrimidine)
Adenine
a dna component, a chemical (purine) that is always combined with a cytosine (pyrimidine)
Guanine
a dna component, a chemical (pyrimidine) that is always combined with an adenine (purine)
Thymine
a dna component, a chemical (pyrimidine) that is always combined with an guanine (purine)
Cytosine
the shape of the DNA molecule, like a twisted ladder
Double Helix
the weak bond that holds nitrogen bases (a,t,c,g) together
Hydrogen Bond
ribonucleic acid, a spiral helix strand that reads dna instructions to make proteins
RNA
a monomer that makes up the polymer protein
amino acid
the process involving transcription & translation whereby proteins are made
protein synthesis
the process where a tRna decodes a rna to make a protein
translation
the process of making rna from a segment of dna called a gene
transcription