Mastering Biology - Chapters 10 and 11 Assignment
Video* of guy holding up his hand
10
. A ___ an abnormally growing mass of cells that is actively spreading through the body.
Malignant Tumor
Gametes are produced by _____.
Meiosis
Normal human gametes carry _____ chromosomes.
23
Homologous chromosomes migrate to opposite poles during _____.
Anaphase I
The first step of bacterial replication is _____.
DNA replication
During _____, the cell carries out its normal functions and the chromosomes are thinly spread out throughout the nucleus.
Interphase
Video* guy standing next to rainbow things
The start of meiosis 1
Video* of two guys standing side by side
centromere
Meiosis starts with a single diploid cell and produces
four haploid cells
Duplication of the chromosomes to produce sister chromatids _____.
occurs in both mitosis and meiosis
During _____ both the contents of the nucleus and the cytoplasm are divided.
the mitotic phase
A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes.
16
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
Which of the following checkpoints does not occur late in G1?
A check that chromosome replication has been successfully completed
Centromeres divide and sister chromatids become full-fledged chromosomes during _____.
Anaphase
The sister chromatids separate and begin moving toward opposite poles of the cell during which phase of mitosis?
Anaphase
What name is given to this process?
Asexual reproduction
Which of these gametes contains one or more recombinant chromosomes?
B and C
A _ is a lump abnormal cells that, although growing out of control, remains at its original site
Benign tumor
Bacteria divide by:
Binary Fission
Which of these cells is (are) haploid?
C and D
In the laboratory, cancer cells fail to show density-dependent inhibition of growth in cell culture. What is one explanation that could account for this?
Cancer cells continuously secrete growth factors into the cell culture medium.
The most common type of cancer is a ___; this type always originates in tissues that line organs.
Carcinoma
Which events occur during prophase?
Chromosomes condense and are attached to spindle fibers. The nuclear envelope breaks down.
During meiosis I, homologous chromosomes form a tetrad and crossing over occurs. What is the outcome of crossing over?
Crossing over creates new combinations of genes present on a single chromosome.
At the end of the mitotic (M) phase, the cytoplasm divides in a process called _________________.
Cytokinesis
Crossing over of chromosomes during meiosis shuffles parental chromosomes, resulting in a genetically unique child.
During prophase I of meiosis I, homologous paternal and maternal chromosomes line up at the metaphase plate. A hybrid chromosome that has crossed over will contain pieces of both the maternal and paternal chromosomes. During meiosis II, sister chromatids separate into four different gametes.
Which of these phases encompasses all of the stages of mitosis?
E
True or false. Mitosis takes place during M phase of the cell cycle, which is longer than interphase.
False
When examining cells in the laboratory, you notice that a particular cell has half as much DNA as the surrounding cells. This observation can be explained if this cell's cell cycle halted at checkpoint _____.
G1
In sexually reproducing multicellular organisms, the main functions of mitosis are _____.
Growth and development Tissue repair/replacement of damaged cells.
Place the events of meiosis in the proper order.
Homologous chromosomes pair up, non-sister chromatids form chiasmata, crossing over occurs, homologous chromosomes separate, sister chromatids separate, four haploid gametes are produced.
You suspect that a serious developmental disorder is due to a chromosome abnormality and prepare a karyotype from an affected individual. In analyzing the karyotype, how could you distinguish trisomy from a chromosome structural defect such as a duplication?
In trisomy there would be one extra chromosome; in a duplication, the number of chromosomes would be normal, but one chromosome would have two copies of a portion of the chromosome.
Nucleoli are present during _____.
Interphase
Drag the labels onto the diagram to identify the stages of the cell cycle.
Interphase Prophase Metaphase Anaphase Telophase
Video* look through microscope with chromosomes lined up 2 by 2. What stage of cellular reproduction are you looking at?
Meiosis 1 only
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 II
___ is the spread of cancer cells from their site of origin to other sites in the body.
Metastasis
Video* process going on in hand
Mitosis
Trisomy for most autosomes is fatal, yet trisomy or even tetrasomy (four copies) of the X chromosome is not. What is the explanation for this difference?
Only one copy of the X chromosome is functional, regardless of the total number of X chromosomes.
Spindle fibers attach to kinetochores during _____
Prometaphase
Chromosomes become visible during _____.
Prophase
The centrosomes move away from each other and the nuclear envelope breaks up during which phase of mitosis?
Prophase
Synapsis occurs during _____.
Prophase I
During _____ a spindle forms in a haploid cell.
Prophase II
Drag each image to the phase of meiosis I it depicts.
See screenshot 1 ***
Drag each image to the phase of meiosis II it depicts.
See screenshot 2 ***
Cytokinesis often, but not always, accompanies _____.
Telophase
Looking through a light microscope at a dividing cell, you see two separate groups of chromosomes on opposite ends of the cell. New nuclear envelopes are taking shape around each group. The chromosomes then begin to disappear as they unwind. You are witnessing _____.
Telophase
The chromosomes arrive at the poles and nuclear envelopes form during which phase of mitosis?
Telophase
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 II
What must happen before a cell can begin mitosis?
The chromosomes must be duplicated.
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.
Although in humans there are 22 pairs of autosomal chromosomes, only three different chromosomal trisomies are commonly seen in newborns. Of the remaining 19 autosomes, many trisomies have not been seen in newborns. Why not?
Trisomy for the other autosomal chromosomes is often lethal, and the affected embryos are miscarried.
Meiosis I produces _____ cells, each of which is _____.
Two ... haploid
In theory, when a nondisjunction for chromosome 18 occurs during meiosis I, four gametes can be produced. If these gametes are fertilized with unaffected gametes from the second parent, what observations would you make concerning the resulting embryos?
Two of the embryos will be trisomic for chromosome 18, and two will contain a single copy of chromosome 18.
Drag the terms to complete the concept map below.
a. diploid organisms b. haploid gametes c. meiosis II d. maternal chromosomes e. crossing over occurs f. sister chromatid separate
Drag the pink labels onto the pink targets to identify the two main phases of the cell cycle. Then drag the blue labels onto the blue targets to identify the key stages that occur during those phase
a. g1 phase b. s phase c. interphase d. g2 phase e. mitotic (m) phase f. mitosis g. cytokinesis
Drag the labels onto the diagram to identify the stages of the life cycle. Not all labels will be used.
a. gametes b. haploid c. meiosis d. fertilization e. diploid f. zygote g. mitosis
Drag the labels to the correct locations on these images of human chromosomes.
a. homologous chromosomes b. centromere c. sister chromatids d. autosomes e. sex chromosomes f. karyotype
Drag the labels onto the grid to indicate the phases of mitosis and meiosis. Use only pink labels for pink targets.
a. mitosis b. prophase c. metaphase d. anaphase, telophase, & cytokinesis e. meiosis f. prophase I g. metaphase I h. anaphase I, telophase 1, & cytokinesis i. meiosis II
Drag the pink labels onto the pink targets to identify key events in mitosis. Then drag the blue labels onto the blue targets to identify the stages of mitosis.
a. mitotic spindle forming b. sister chromatids centered c. chromosome separating d. nuclear envelope e. interphase f. prophase g. metaphase g. anaphase i. telophase and cytokinesis
Drag the labels onto the diagram to identify the various chromosome structures.
a. pair of homologous chromosomes b. centromere c. sister chromatid
The function(s) of meiosis is/are _____.
a. reproduction (production of gametes)
What is different concerning the DNA in bacterial cells as opposed to eukaryotic cells?
all of the above are differences between prokaryotic and eukaryotic DNA
During _____ sister chromatids separate.
anaphase II
An individual with a malignant tumor is said to have ___
cancer
A cell is treated with a drug that prevents the formation of vesicles. Which of the following processes depends on the formation of vesicles and would therefore be blocked?
cytokinesis in a plant cell
Meiosis starts with _____ cells and produces _____ gametes.
diploid ... haploid
Cytokinesis _____.
finishes mitosis by dividing the cytoplasm and organelles of the original parent cell into two separate daughter cells
Meiosis II typically produces _____ cells, each of which is _____.
four ... haploid
Fertilization joins _____ to produce a _____.
haploid gametes ... diploid zygote
The _____ separate in meiosis I; the _____ separate in meiosis II.
homologous chromosomes ... sister chromatids
During prophase I of meiosis,
homologous chromosomes stick together in pairs.
Which processes lead to most genetic variation in sexually reproducing organisms?
independent orientation of chromosomes in meiosis crossing over random fertilization
A cell preparing to undergo meiosis duplicates its chromosomes during
interphase
During _____ the cell grows and replicates both its organelles and its chromosomes.
interphase
If it weren't for _____, chromosome number would double with every generation of sexual reproduction.
meiosis
Looking through a light microscope at a cell undergoing meiosis, you see that the chromosomes have joined into XX-shaped tetrads. These tetrads are lined up along a plane that runs through the center of the cell. This cell is in _____.
meiosis I
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
During meiosis, segments of non-sister 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
The correct order of events during meiosis is
prophase I, metaphase I, anaphase I, telophase I, cytokinesis, meiosis II.
This image shows a step that is partway through meiosis.
separation of sister chromatids into distinct cells production of four haploid gametes
Mitosis occurs in _____; meiosis occurs in _____.
somatic or body cells ... germ cells in the testes or ovaries
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
Meiosis is typically accomplished in _____.
three steps. All of the chromosomes are duplicated in a diploid cell, and then there are two cell divisions to produce a total of four haploid gametes.
During prophase a homologous pair of chromosomes consists of _____.
two chromosomes and four chromatids