Biology Chapter 8 HW
Homologous chromosomes migrate to opposite poles during ______.
- Anaphase 1 (During anaphase 1 sister chromatids remain attached at their centromeres, and homologous chromosomes move to opposite poles)
If a hypothetical organism has 5 chromosomes in one of its gametes, then how many chromosomes must it have in a body cell just before mitosis?
- 10 chromosomes
A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _______ chromosomes.
- 16 chromosomes (16 is half of 32)
Normal human gametes carry _____ chromosomes.
- 23 (This is the number of chromosomes in a single set of human chromosomes)
Which of these is NOT a carcinogen? A) Testosterone B) Cigarette smoke C) Fat D) UV light E) All of the above are carcinogens
- All of the above are carcinogens (Testosterone, cigarette smoke, fat, UV light are all substances that can cause cancer)
Chromosomes separate during _______.
- Anaphase
The sister chromatids separate and begin moving toward opposite poles of the cell during which phase of mitosis?
- Anaphase
Centromeres divide and sister chromosomes become full-fledge chromosomes during ______.
- Anaphase (During anaphase, sister chromatids separate and migrate to opposite poles)
During _____ sister chromatids separate.
- Anaphase 11 (Anaphase 11 is essentially the same as mitotic anaphase except that the cell is haploid)
What is the process called when a single individual is reproducing?
- Asexual reproduction
_______ reproduction is a means of creating new individual solely by _______, the form of cell division that creates genetically identical daughter cells.
- Asexual.......Mitosis
A ______ is a lump of abnormal cells that, although growing out of control, remains at its original site.
- Benign tumor
Bacteria divide by _____.
- Binary fission (Binary fission is the method used by bacteria to divide)
An individual with a malignant tumor is said to have ______.
- Cancer
Diploid
- Cell contains two complete sets of chromosomes (Mitosis)
Haploid
- Cell has only one set of chromosomes (Meiosis)
What structure joins sister chromatids?
- Centromere (The centromere is the point of attachment between two duplicated chromosomes)
Telophase
- Chromosomes become less condensed - New nuclear envelopes formed
Recombinant Chromosomes
- Composed of materials from both parents
At the end of the mitotic (M) phase, the cytoplasm divides in a process called ______.
- Cytokinesis
The first step of bacterial replication is ______.
- DNA replication (The DNA must be copied in order to proceed)
_______ is a carcinogen that promotes colon cancer.
- Fat (A diet high in fat increases the risk of both colon and breast cancer)
Meiosis starts with a single diploid cell and produces ______.
- Four haploid cells
Meiosis 11 produces ______ cells, each of which is _____.
- Four.....Haploid (At the end of meiosis 11 there are four haploid cells)
During prophase 1 of meiosis, ________.
- Homologous chromosomes stick together in pairs
During _____ the cell grows and replicates both its organelles and its chromosomes.
- Interphase
A cell preparing to undergo meiosis duplicates its chromosomes during ____.
- Interphase (Chromosomes are duplicated during interphase)
Nucleoli are present during _____.
- Interphase (Nucleoli are present during interphase)
A ______ is an abnormally growing mass of cells that is actively spreading through the body.
- Malignant tumor
Gametes are produced by ________.
- Meiosis (Meiosis produces haploid gametes from a diploid parental cell)
In the stages of meiosis what stage are haploid?
- Meiosis 1 and Meiosis 2 (Once meiosis 1 is complete, cells are haploid)
What stage of cellular reproduction has chromosomes lined up two-by-two?
- Meiosis 1 only (Meiosis 1 is the only time that chromosomes line up by homologous pairs)
Sister chromatids center during _______.
- Metaphase
The chromosomes line up in the center of the cell during which phase of mitosis?
- Metaphase
During _____ chromosomes align single file along the equator of a haploid cell.
- Metaphase 11 (Metaphase 11 is essentially the same as mitotic metaphase except that the cell is haploid)
_______ is the spread of cancer cells from their site of origin to other sites in the body.
- Metastasis
Prophase
- Microtubules form the mitotic spindle - The nuclear envelope breaks up
What process is going on in your hand right now?
- Mitosis (Mitosis takes place anywhere in the body)
Spindle fibers attach to kinetochores during ______.
- Prometophase (Attachment of spindle fibers to kinetochores is one of the events of prometaphase)
Mitotic spindle forms during _______.
- Prophase
The centrosomes move away from each other and the nuclear envelope breaks up during which phase of mitosis
- Prophase
Chromosomes become visible during _______.
- Prophase (During prophase, the chromatin fibers become discrete chromosomes)
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 1 (Segments of nonsister chromatids trade places during prophase 1, resulting in recombination)
Synapsis occurs during _____.
- Prophase 1 (Synapsis, the pairing of homologous chromosomes, occurs during prophase 1)
The correct order of events during meiosis is: _______,
- Prophase 1, Metaphase 1, Anaphase 1, Telophase 1, cytokinesis, meiosis 11
During ____ a spindle forms in a haploid cell.
- Prophase 11 (Prophase 11 is essentially the same as mitotic prophase except that the cells are haploid)
______ reproduction, in contrast, generates genetically unique offspring. To accomplish this, a organism must produce _____ ---sperm and egg--- through the process of _______. The cells produced this way will be ______, meaning that they contain a single set of chromosomes. Such cells are produced only in the _____.
- Sexual.......Gametes.........Mitosis.........Haploid........Gonads
Anaphase
- Sister chromatids separate and become full-fledged chromosomes that move to opposite poles
Cytokinesis often, but not always, accompanies ________.
- Telophase
The chromosomes arrive at the poles and nuclear envelopes form during which phase of mitosis?
- Telophase (Final stage of mitosis)
At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids.
- Telophase 1
At the end of _____ and cytokinesis there are four haploid cells.
- Telophase 11
The nuclear envelope forms during ______.
- Telophase and cytokinesis
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
What must happen before a cell can begin mitosis?
- The chromosomes must be duplicated (The chromosomes, or genetic material must be copied first)
Cytokinesis
- The cytoplasm divides
During _____ both the contents of the nucleus and the cytoplasm are divided.
- The mitotic phase (The mitotic phase encompasses both mitosis and cytokinesis)
Metaphase
- The mitotic spindle is fully formed - Chromosomes are lined up in the center of the cell
If the chromosomes are duplicated and lined up by homologous pair, what stage of cell reproduction are they in?
- The start of meiosis 1
During prophase a homologous pair of chromosomes consists of _______.
- Two chromosomes and four chromatids (At this point each of the chromosomes consists of two chromatids)
Meiosis 1 produces ______ cells, each of which is _____.
- Two.....Haploid (At the end of meiosis 1 there are two haploid cells)
Interphase
- Where most of the cell's life is spent - When growth occurs - Cells that are about to divide replicate their DNA