Use this to study for the Chapter 8 test
When the chromatin condenses DNA _____?
Wraps its self around the proteins
A pair of sex chromosomes found in a human male is most like
a bride and groom.
With the exception of identical twins, siblings who have the same two biological parents are likely to look similar, but not identical, to each other because they have
a similar but not identical combination of genes.
Centromeres divide and sister chromosomes become full-fledged chromosomes during _____.
anaphase
Homologous chromosomes migrate to opposite poles during _____.
anaphase I
In many organisms, including humans, chromosomes are found in homologous pairs. Homologous chromosomes _____.
are identical in the arrangement of their genes, but some versions of the genes may differ between the chromosomes
Strictly speaking, the phrase "like begets like" refers to
asexual reproduction only.
Bacteria divide by:
binary fission
At the end of the mitotic (M) phase, the cytoplasm divides in a process called _________________.
cytokinesis
In bacterial cells, binary fission involves _____.
distribution of a copy of the single parental chromosome to each daughter cell
When forming buds, hydras _____.
divide by mitosis
Cytokinesis refers to _____.
division of the cell outside the nuclear material
At the end of telophase 1, two daughter cells are produced each other with the haploid number of _____?
double chromosomes
Chromatids form _____.
during the S phase
The diploid phase of the human life cycle begins with _____.
fertilization
Which of the following is a feature of plant cell division that distinguishes it from animal cell division?
formation of a cell plate
Meiosis II typically produces _____ cells, each of which is _____.
four ... haploid
What is the typical result when a diploid cell undergoes meiosis?
four haploid cells
Meiosis starts with a single diploid cell and produces
four haploid cells.
During asexual reproduction, yeast cells can produce _____.
genetically identical offspring
At the conclusion of meiosis I, the daughter cells are _____.
haploid and the sister chromatids are joined
In anaphase I, _____.
homologous chromosomes move toward opposite poles
During prophase I of meiosis,
homologous chromosomes stick together in pairs.
Two chromosomes in a nucleus that carry genes controlling the same inherited characteristics are
homologous chromosomes.
Chromatids are _____.
identical copies of each other if they are part of the same chromosome
Nucleoli are present during _____.
interphase
A cell preparing to undergo meiosis duplicates its chromosomes during
interphase.
When we say that an organism is haploid, we mean that _____.
its cells each have one set of chromosomes
Gametes are produced by _____.
meiosis
If it weren't for _____, chromosome number would double with every generation of sexual reproduction.
meiosis
At which stage of mitosis are chromosomes lined up in one plane in preparation for their separation to opposite poles of the cell?
metaphase
During which phase of mitosis do the chromosomes line up on a plane equidistant from the two spindle poles?
metaphase
During _____ chromosomes align single file along the equator of a haploid cell.
metaphase II
Looking through a light microscope at a cell undergoing division, you see that the condensed chromosomes have lined up along the midline of the cell. The homologous pairs are NOT joined in tetrads. Each chromosome takes its own place in line, independent of its homolog. You are witnessing _____.
metaphase of mitosis
After fertilization, the resulting zygote begins to divide by _____.
mitosis
Consider the process by which bacterial populations grow. What process performs a similar function in humans?
mitosis
Duplication of the chromosomes to produce sister chromatids _____.
occurs in both mitosis and meiosis
Spindle fibers attach to kinetochores during _____.
prometaphase
At which point do centrosomes begin to move apart to the opposite poles of the cell in a dividing human liver cell?
prophase
Chromosomes become visible during _____.
prophase
In the telophase of mitosis, the mitotic spindle breaks down and the chromatin uncoils. This is essentially the opposite of what happens in _____.
prophase
Crossing over occurs during _____.
prophase I
Synapsis occurs during _____.
prophase I
The correct order of events during meiosis is
prophase I, metaphase I, anaphase I, telophase I, cytokinesis, meiosis II.
During meiosis, segments of nonsister chromatids can trade places. This recombination of maternal and paternal genetic material is a key feature of meiosis. During what phase of meiosis does recombination occur?
prophase I.
During _____ a spindle forms in a haploid cell.
prophase II
In meiosis II, _____.
sister chromatids are separated
Mitosis occurs in _____; meiosis occurs in _____.
somatic or body cells ... germ cells in the testes or ovaries
Cytokinesis often, but not always, accompanies _____.
telophase
During which phase of mitosis does the nuclear envelope re-form?
telophase
At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids.
telophase I
At a critical point in meiosis, the chromosomes do not replicate. This occurs between _____.
telophase I and prophase II
At the end of _____ and cytokinesis there are four haploid cells.
telophase II
DNA replication occurs in _____.
the S phase of interphase
One event occurring during prophase is _____.
the beginning of the formation of the mitotic spindle
During mitosis, the chromosomes move because _____.
they attach to a dynamic, precisely regulated mitotic spindle
Individual chromosomes are usually observed with a light microscope during mitosis, even though cells spend more time in interphase. This is because _____.
they have uncoiled to form long, thin strands
Meiosis I produces _____ cells, each of which is _____.
two ... haploid
During prophase a homologous pair of chromosomes consists of _____.
two chromosomes and four chromatids
At the end of telophase I of meiosis, as cytokinesis occurs, there are _____.
two haploid cells
What is different concerning the DNA in bacterial cells as opposed to eukaryotic cells?
-the amount of DNA present - whether the DNA is housed in a nucleus or not - whether the DNA is linear or circular
A cell biologist carefully measured the quantity of DNA in grasshopper cells growing in cell culture. Cells examined during the G2 phase of the cell cycle contained 200 units of DNA. What would be the amount of DNA in one of the grasshopper daughter cells?
100 Units
A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes.
16
Baker's yeast is an organism with 32 chromosomes that can perform asexual or sexual reproduction and exist as both a diploid and haploid cell. After meiosis, how many chromosomes will be present in each cell?
16
Prophase is the _____ stage of mitosis.
1st
How many stages of meiosis are there?
2, meiosis 1 and meiosis 2
Normal human gametes carry _____ chromosomes.
23
A certain species of animal has six pairs of chromosomes. How many DNA molecules are present in the nuclei of these animals during G2 phase?
24
What is another name for a diploid cell?
2N cell
Metaphase is the _____ stage of mitosis.
2nd
Anaphase is the _____ stage of mitosis.
3rd
In humans, a diploid cell has _____ chromosomes?
46
Telophase is the _____ stage of mitosis.
4th
In a cell containing 10 chromosomes, meiosis results in the formation of daughter cells containing _____ chromosomes.
5
Oncogene is _____?
A cancer causing agent
A diploid cell is is _____?
A cell containing a duplicate set of chromosomes
A haploid cell is _____?
A cell containing a single set of chromosomes
Cancer cell is _____?
A cell that is not subject to normal cell-cycle control mechanisms
Mutation is _____?
A change in the nucleotide sequence of DNA
Which of the following checkpoints does not occur late in G1?
A check that chromosome replication has been successfully completed
Mutagen is _____?
A chemical or physical agent that interacts with DNA causing a mutation
Carcinogen is _____?
A chemical or physical agnet that causes cells to become cancerous
Duplicated Chromosome is _____?
A chromosome HAS been duplicated
Single Chromatin is _____?
A chromosome which as NOT been duplicated
Gene is _____?
A discrete unit of hereditary information consisting of a specific nucleotide base sequence of DNA
A nucleotide is _____?
A monomer of a nucleic acid, either DNA or RNA
Tumor suppressor gene is _____?
A normal gene whose protein product inhibits tumor growth and cell division
Proto-oncogene is _____?
A normal gene whose protein product stimulates an increase in call division
Growth factor is _____?
A protein secreted by certain cells in the body that stimulates cell division
A gamete is _____?
A sex cell
An example of a gamete is _____?
A sperm cell, of an egg cell
Centeomere is _____?
A structure made of protein which holds the two halves of a duplicated chromosome together
RNA is _____?
A type of nucleic acid consisting of nucleotides linked together
The four nitrogenous bases in DNA are _____?
Adenine, Cytosine, Guanine, and Thymine
The four nitrogenous bases in RNA are _____?
Adenine, Cytosine, Guanine, and Uracil
Which of the following statements is false?
An X chromosome is an autosome.
Tumor is _____?
An abnormal mass of cells that forms within otherwise normal tissue
Benign tumor is _____?
An abnormal mass of cells that remains at its original site in the body and does not travel to other parts of the body
Malignant tumor is _____?
An abnormal tissue mass of cells that can spread into neighboring tissue and to other parts of the body
Centromeres of duplicated cells divide and split happens during _____ phase?
Anaphase
The mitotic spindle pulls the sister chromosomes apart happens during _____ phase?
Anaphase
The sister chromatids separate and begin moving toward opposite poles of the cell during which phase of mitosis?
Anaphase
The sister chromosomes are on opposite ends of the two poles of a cell during _____ phase?
Anaphase
The spindle pulls the tetrads apart during which phase?
Anaphase 1
The spindle separates the pairs of homologous chromosomes from each other as they move to opposite poles of the cell, during which phase?
Anaphase 1
Chromosomes _____ duplicated, there is NO S phase between meiosis 1 and meiosis 2?
Are NOT
During Metaphase 1 the centromeres of homologous chromosomes _____ on the equator?
Are NOT
Rarely a mutation occurs that is _____ to an organism that allows it to make a new proteins capable of new functions?
Beneficial
Carcinoma is _____?
Cancer that originated in the coverings or linings of the body, such as the skin, intestinal lining, or lungs
Lymphoma is _____?
Cancer that originates from the lymh nodes or white blood cells
Leukemia is _____?
Cancer that originates in the blood forming tissues
Sarcoma is _____?
Cancer that originates in the blood forming tissues
Many _____ interact with the DNA to cause mutations that lead to cancer?
Carcinogens
Some mutagens are also _____?
Carcinogens
Which of the following statements regarding cell division is false?
Cell division is common in eukaryotes but rare in prokaryotes.
_____ looks like a single chromosome?
Chromatid
Which of the following statements regarding the differences between mitosis and meiosis is false?
Crossing over is a phenomenon that creates genetic diversity during mitosis.
Guanine will only bond to _____?
Cytosine
The centromeres of the chromosomes are lined up _____ the equator of the cell?
DIRECTLY on
Genes are made of _____ so they are found on the chromosomes in the _____ of all eukaryotic cells?
DNA Nucleus
Nucleotides are the building blocks of _____ and _____?
DNA and RNA
Which of the following statements correctly describes the timing of DNA synthesis?
DNA is synthesized in the S phase of interphase.
The first step of bacterial replication is _____.
DNA replication
S Phase is _____?
DNA replication and thus chromosome duplication
DNA stands for _____?
Deoxyribonucleic acid
The nucleotides that make up DNA are made up of _____?
Deoxyribose sugar molecule
Once crossing over is complete, the chromosomes are formed are _____ than the original homologous chromosomes that formed on the original tetrad?
Different
During Anaphase 1, centromeres _____ divide and the sister chromatids that make up each double chromosome remain attached?
Do NOT!
Chromosome number _____ change diploid to diploid.
Does NOT
Prophase 1 begins with a single diploid cell containing _____?
Duplicate chromosomes
True or false. Mitosis takes place during M phase of the cell cycle, which is longer than interphase.
False
Nearly all cells of the organism are diploid except for _____?
Gametes
The _____ on each homologous chromosome is somewhat different than the information on the sister homogenous chromosome is attached to the centromere?
Genetic information
_____ regulate the cell cycle in cells?
Growth factors
Oncogenes are often the genes for _____ or _____ that control the cell cycle?
Growth factors Related proteins
The most common physical mutation is _____ or _____?
High-energy radiation such as x-rays or ultraviolet light
One _____ is inherited from organisms father, the other _____ chromosome is inherited from organisms mother?
Homologous chromosome Homologous
To form a double stranded DNA molecule, each of the bases will only form _____ bonds with _____?
Hydrogen Other specific bases
The two strands of DNA are held together by _____ and the two strands are _____ into a helical formation?
Hydrogen bonds Wound around each other
What is a tetrad?
It has four chromatids
Chromatin is _____?
Long fibers of DNA
The chromosomes line up in the center of the cell during which phase of mitosis?
Metaphase
The mitotic spindle moves the duplicated chromosomes so they are lined up on the 'cell equator' happens during _____ phase?
Metaphase
The homologous chromosomes have their centromeres next to and on each of the side of the equator, happens during which phase?
Metaphase 1
The spindle moves the chromosome tetrads so they're lined up at the cells equator, happens during which phase?
Metaphase 1
The "equator of the cell" is another name for the _____?
Metaphase plate
Which of the following statements regarding the function of mitosis is false?
Mitosis allows organisms to generate genetic diversity.
Many _____ are harmful and can lead to the synthesis of abnormal and nonfunctional proteins which could cause cell death or cancer
Mutations
What is another name for a haploid cell?
N cell
Complementary bases are _____?
Nitrogenous bases in nucleic acids that will form hydrogen bonds with each other
_____ proteins hyper stimulate mitosis?
Oncogene
Mutated proto-oncogenes becomes _____?
Oncogenes
A haploid cell has _____ the number of chromosomes of a diploid cell of the same organism?
One half
Chromatid is _____?
One half of a duplicated chromosome
Deoxyribose sugar molecule are attached to _____ and _____ in nucleotides of DNA?
Phosphate group Nitrogenous base
The nucleotides that make up RNA are attached to a _____ and _____?
Phosphate group Nitrogenous base
Chromatin condenses to form duplicated chromosomes happens during _____ phase?
Prophase
During _____ chromosomes are formed?
Prophase
The centrosomes move away from each other and the nuclear envelope breaks up during which phase of mitosis?
Prophase
The nuclear envelope breaks down happens during _____ phase?
Prophase
The spindle attaches to the centromeres of chromosomes happens during _____ phase?
Prophase
The spindles apparatus forms happens during _____ phase?
Prophase
Crossing over (also known as synapsis) happens during which phase?
Prophase 1
Duplicated chromosomes condense from chromatin, happens during which phase?
Prophase 1
Homologous chromosomes pair up to from a tetrad, happens during which phase?
Prophase 1
Nuclear envelope breaks down, happens during which phase?
Prophase 1
Spindle forms and begins moving homologous chromosomes toward the center of the cell, happens during which phase?
Prophase 1
Which stage in meiosis is the longest?
Prophase 1
What stages make up meiosis 1?
Prophase 1, Metaphase 1, Anaphase 1, and Telophase 1
List the stages of mitosis.
Prophase, Metaphase, Anaphase, Telaphase
DNA which is not condensed is bound to a _____?
Protein
RNA stands for _____?
Ribonucleic acid
The nucleotides that make up RNA are made up of _____?
Ribose sugar molocules
During crossover, chromatids of homologous chromosomes exchange _____?
Segments
RNA is usually a _____ and plays important roles in _____ synthesis.
Single stranded molecule Protein
Usually the _____ and _____ are the only haploid cells?
Sperm and the egg
Duplicated chromosomes decondense back into chromatin happens during _____ phase?
Telophase
Mitotic spindle breaks down during _____ phase?
Telophase
The chromosomes arrive at the poles and nuclear envelopes form during which phase of mitosis?
Telophase
The nuclear envelope begins to form during _____ phase?
Telophase
The chromosomes only begin to decondense back into chromatin, during which phase?
Telophase 1
The mitotic spindle only begins to break down, during which phase?
Telophase 1
The nuclear envelope only begins to reform around the chromosomes so that two separate daughter nuclei are created, happens during which phase?
Telophase 1
At the end of _____, two daughter cells are produced, each with the diploid number of chromosomes, the _____ as in the original mother cell.
Telophase of mitosis Same number
Sugar-phosphate back bone is _____?
The "sides of the ladder" in a molecule of DNA
Chromosomes are duplicated during _____?
The S phase of interphase
What must happen before a cell can begin mitosis?
The chromosomes must be duplicated.
DNA polymerase is _____?
The enzyme that assembles DNA nucleotides into the two strands of DNA
DNA is _____?
The genetic material that organisms inherit from their parents
What would be the immediate consequence of destroying a cell's centrosomes?
The mitotic spindle would not form.
The M phase of mitosis and M phase of meiosis both occur after interphase. However, the two processes differ in the arrangement and behavior of their chromosomes. How?
The pairing up of homologous chromosomes and crossing over only occur during meiosis.
Interphase is _____?
The period in the cell cycle when the cell is NOT actually dividing
Homologous chromosomes are _____ length, in _____ position, and staining pattern and possess genes for the same traits?
The same Centromere
Two diploid daughter cells are produced with _____ and _____ of the original mother cell which underwent mitosis.
The same chromosome number Genetic make up
Within one chromosome, what is the relationship between the sequence of bases in DNA of one sister chromatid compared to the other?
The sequences are identical.
Metastasis is _____?
The spread of cancerous cells beyond their original site in the body by way of the circulatory or lymph vessels
DNA double helix is _____?
The three dimensional structure of DNA
Homologous chromosomes are _____?
The two chromosomes that make up a matched pair in a diloid cell
The sugar and phosphate groups of each nucleotide in a strand of DNA are linked together with _____?
Their nitrogenous bases
Adenine will only bond to _____?
Thymine
A diploid cell has _____ the number of chromosomes of a haploid cell of the same organism?
Twice