BIO Unit 4 (CH 11 & 12)
List 3 hallmarks of malignant cells
1. Abnormal growth and development 2. Altered cytoplasm and plasma membrane (EX: cells shape is wrong, cannot function - specialized cell -> altered cell) 3. Metastasis- cells spread from one part of body to another (cancer)
benign tumor
1. slow growth 2. maintain cell plasma membrane adhesion proteins which anchors them to neighbor cells in the tissues they're in so that they do not wander 3. Incapsulated to keep cells together
telophase 1
2 new nuclei ae formed, each has one of each duplicated chromosome
telophase 2
4 new nuclei formed; each cell with one of each unduplicated chromosome
A typical cell spends most of its time in a. interphase b. mitosis c. cytokinesis
A
Because of their surface-to-volume ratio, cells function most efficiently when they are relatively ______ . For organisms to grow larger, they need to add more cells. A. small B. large
A
DNA replication occurs during a. interphase b. mitosis c. cytokinesis
A
If a cells DNA is damaged, the products of ____ genes interact to advance, delay, or stop the cell cycle. A. Checkpoint B. Master C. Onco
A
In which of the stages below does the chromosome consist of 2 DNA molecules? 1 metaphase, 2 telophase, 3 prophase, 4 anaphase A. 1&2 B. 1, 3 & 4 C. 1,2&3 D. 3&4
A
In which stage of meiosis is the chromosome number halved? A. Anaphase I B. Prophase I C. Metaphase I D. Telophase I
A
Mouse cells have 40 total individual chromosomes. Therefore, they have A. 20 B. 80 C. 40 homologous chromosome pairs.
A
Organisms add more cells to their bodies by ___. A. copying the cells they already have B. absorbing new cells from the food they eat
A
What occurs during the anaphase stage of mitosis? A. Sister chromatids separate and move toward opposite spindle poles. B. All chromosomes are aligned midway between spindle poles. C. Chromosomes pack tightly and become attached to a newly forming spindle. D. Chromosomes arrive at opposite spindle poles and become enclosed by a new nuclear envelope.
A
Which is NOT true of human chromosomes? A. Human gametes end up with two of each type of 23 chromosomes B. The diploid number is 46. C. There are 23 pairs of chromosomes. D. The haploid number is 23.
A
Which of the following defines a telomere? A. A region of noncoding DNA at the end of a chromosome that protects coding sequences from degradation B. An accumulation of abnormally dividing cells C. A disk-shaped structure that forms and partitions descendant cells during cytokinesis in a plant cell D. Temporary structure of microtubules that moves chromosomes during nuclear division
A
Which of the following is NOT an example of fail-safe mechanisms that prevent the irregular cell divisions characteristic of cancer? A. Mutation in a tumor suppressor gene B. Shortening of telomeres C. Triggered cell death D. Cell division limit
A
Which of the following is an advantage of asexual reproduction over sexual reproduction? A. Asexual reproduction does not require a partner. B. The resulting offspring have no genetic diversity. C. Asexual reproduction requires a partner. D. Asexual reproduction leads to offspring with high genetic diversity.
A
Which of the following is an advantage of sexually reproducing populations over asexually reproducing populations? A. Sexually reproducing populations are more resilient against the effects of harmful mutations. B. Sexually reproducing populations produce genetically identical offspring. C. Sexually reproducing populations require partners to reproduce. D. Sexually reproducing populations do not require partners to reproduce.
A
Which of the following occurs during metaphase I? A. Homologous chromosome pairs are aligned midway between spindle poles. B. A complete set of chromosomes cluster at each cell end, and two haploid nuclei are produced. C. The spindle separates the homologous chromosomes and moves them toward opposite spindle poles. D. Homologous chromosomes pack tightly, pair up, and swap segments.
A
Which of the following stages of meiosis II involves separation and movement of the sister chromatids toward the spindle poles? A. Anaphase II B. Telophase II C. Prophase II D. Metaphase II
A
Which phase of interphase is characterized by DNA replication? A. S B. G1 C. G2
A
sexual reproduction
A reproductive process that involves two parents that combine their genetic material to produce a new organism, which differs from both parents
Which of the following are characteristics of benign tumors? Select all that apply. A. They stay in their home tissue. B. They are slow growing. C. They grow quickly. D. They can migrate and grow in other tissues through metastasis.
A, B
Which of the following are stages in the cytokinesis of animal cells? Select all that apply. A. After telophase, the contractile ring constricts the plasma membrane and forms a cleavage furrow. B. The contractile ring reaches its smallest diameter, and the spindle microtubules are cut as vesicles form the new membranes that separate the two new cells. C. A contractile ring of microfilaments and motor proteins forms under the plasma membrane during anaphase. D. The cell plate expands along the plane of division, and when the plate fuses with the plasma membrane, the cytoplasm is partitioned into two new cells.
A, B, C
Which of the following is a stage of mitosis? Select all that apply. A. Metaphase B. Anaphase C. Interphase D. Telophase E. Prophase
A, B, D, E
A. Mitosis B. Meiosis ______ is a nuclear division mechanism that maintains the _____. C. chromosome number D. cell number .
A, C
In sexual reproduction, ____ A. meiosis B. mitosis produces genetically diverse ____. C. haploid gametes D. triploid cells E. diploid cells
A, C
During human fertilization, ____ A. a male gamete and a female gamete B. two female gametes C. two male gametes fuse to produce a ____. D. zygote E. female germ cell F. male germ cell
A, D
During plant cell cytokinesis, a network of parallel microtubules condenses around the ____ . A. future plane of division B. cleavage furrow C. contractile ring This becomes a site of expansion of the ____, D. cell plate E. cleavage furrow F. contractile ring which fuses with the plasma membrane and partitions the cytoplasm into two cells.
A, D
Gametes are ____ A. haploid B. diploid C. triploid cells that have a single set of chromosomes. The number of chromosomes in diploid zygotes is represented as ____ D. 2n E. n F. 3n .
A, D
In both mitosis and ____, A. meiosis II B. meiosis I a spindle forms and separates sister chromatids. While mitosis produces two nuclei, meiosis II produces ____. C. four haploid nuclei D. two haploid nuclei
A, D
Neoplasms
Accumulation of abnormally dividing cells
During which stage of meiosis does crossing over occur? A. Anaphase II B. Prophase I C. Prophase II D.Metaphase I
B
During which stage of mitosis are the chromosomes aligned midway between the spindle poles? A. Prophase B. Metaphase C. Anaphase D. Telophase
B
In a mouse cell that has duplicated its DNA and is beginning mitosis, there are A. 20 B. 80 C. 40 sister chromatids.
B
In which stage of mitosis do the chromosomes reach opposite sides of the cells and a new nuclear envelope forms around each cluster of chromosomes? A. Prophase B. Telophase C. Metaphase D. Anaphase
B
What occurs during the prophase stage of mitosis? A. Chromosomes arrive at opposite spindle poles and become enclosed by a new nuclear envelope B. Chromosomes pack tightly and become attached to a newly forming spindle C. Sister chromatids separate and move toward opposite spindle poles D. Chromosomes align midway between the spindle poles
B
Which of the following defines a germ cell? A. A mature, haploid reproductive cell B. An immature reproductive cell that gives rise to haploid gametes when it divides C. A diploid cell that forms when two gametes fuse D. A form of a gene that may encode for different versions of the gene's product
B
Which of the following is an outcome of crossing over? A. The production of genetically identical offspring B. The introduction of novel combinations of alleles in offspring C. The production of gametes D. The formation of a zygote
B
DNA replication occurs during a. G1 b. G2 c. S
C
During mitosis, the spindle fibers extend from the ____ and attach to the____. A. Centrosomes, homologous pairs of chromosomes B. Spindle, homologous pairs of chromosomes C. Centrosomes, sister chromatids D. Centrosomes, the spindle
C
Mitosis is a nuclear division mechanism that a. cuts the chromosome # in half b. changes a diploid cell into a haploid cell c. maintains the chromosome #
C
Which of the following occurs during metaphase II? A. Spindle microtubules attach to each sister chromatid as the nuclear envelope breaks up. B. The sister chromatids separate and move toward the spindle poles. C. The chromosomes align midway between spindle poles. D. A nuclear envelope forms around each set of chromosomes to form four haploid nuclei.
C
Which of the following occurs during the G2 stage of interphase? A. The cell grows and produces molecules for DNA replication. B. The cell undergoes mitosis. C. The cell produces the proteins and cellular components needed for division. D. The cell undergoes DNA replication.
C
Interphase
Cell GROWS, RECOVER, & performs its NORMAL FUNCTIONS, and prepares for division; consists of G1, S, and G2 phases
Cytokinesis in animal cells
Cell membrane is drawn inward until the cytoplasm is pinched into two nearly equal parts; CLEAVAGE FURROW
How do mutations in growth factor genes give rise to neoplasms?
Check point genes mutate, cells make too much or too little of gene product, cell could lose control of cell cycle: skipping interphase so division occurs with no breaks, abnormal cells may not self-destruct (apoptosis)
Describe crossing over and how it introduces variation in traits among the offspring of sexual reproducers.
Crossing over- nonsister chromatids swap segments and mix info on same gene which gives different combos to offspring
A mutated gene that transforms a normal cell into a tumor cell is called a (n) A. checkpoint gene B. neoplasm C. proto-oncogene D. oncogene
D
Checkpoint gene products that inhibit mitosis are called A. Oncogene B. Neoplasms C. Proto-oncogenes D. Tumor suppressors
D
Cytokinesis (cytoplasmic division) in animal cells involves A. Separation of sister chromatids into two new nuclei B. Vesicles lining up at the cell equator and fusing in a structure called a cell plate C. Nuclear division D. A cleavage furrow that is formed by a ring of protein filaments around the equator of the cell
D
Sexual reproduction A. Leads to uniform characteristics in a population B. Produces genetic clones. C. Produces genetic clones and requires less tissue differentiation than asexual reproduction D. Results in a new combo of genetic traits.
D
Which of the following demonstrates the link between oncogenes and cancer? A. They are genes that transform tumor cells into normal cells. B. Oncogenes produce molecules that inhibit mitosis. C. Oncogenes do not have mutations that increase the activity or number of molecules that stimulate mitosis. D. The mutations in oncogenes increase the activity or number of molecules that stimulate mitosis, leading to irregular cell division.
D
Which of the following stages of meiosis II involves the attachment of spindle microtubules to each sister chromatid? A. Telophase II B. Metaphase II C. Anaphase II D. Prophase II
D
Which stage of meiosis I is characterized by the formation of two haploid nuclei? A. Anaphase I B. Prophase I C. Metaphase I D. Telophase I
D
Allele
Different forms of a gene
Zygote
Diploid cell formed by fusion of two gamete cells; divides to form an embryo of a new organism
Describe how genetic diversity makes a population more resilient to environmental changes.
Diversity offers a better choice of surviving environmental changes because some combos of traits are better suited for survival
Metaphase 2
Duplicated chromosomes align at the cell equator
Why are cell cycle checkpoints important?
Ensure that a cell does not enter one stage of the cell cycle until the previous stage is complete Monitor completion of DNA copying, DNA damage, and nutrient availability
Sister chromatids become separated and individual chromosomes during telophase. T/F?
False
Fertilization
Fusion of two gamete cells
The interval of cell growth before DNA replication
G1
Which phase of interphase is characterized by a period of cell growth and the production of molecules for DNA replication? A. G1 B. S C. G2
G1
The interval when the cell prepares to divide
G2
how are tumor suppressors helpful?
Gene that normally inhibits mitosis preventing cell to divide preventing abnormal growths
First division seperates
HOMOLOGOUS PAIRS
Explain why homologous chromosomes may carry different alleles.
Homologous chrom. may carry different alleles because one chromosome came from mom, other from dad.
Metaphase 1
Homologous chromosomes line up at the equator
anaphase 1
Homologous chromosomes pairs and separate and move to opposite poles
Sister chromatids
Identical copies of a chromosome; full sets of these are created during the S subphase of interphase.
Mitosis is necessary for body processes including:
Increases in body size, tissue remodeling, asexual reproduction
Describe the phases and the main events of meiosis in a diploid cell.
Interphase (DNA replication) Meiosis 1 (First nuclear division) (haploid) Meiosis 2 (P2m2a2t2)
Gamete
Mature haploid reproductive cell
Describe the major differences between meiosis 1 and meiosis 2
Meiosis 1 halves chromosomes Meiosis 2 is like mitosis- ends up with unduplicated chromosomes (separate chromatids)
Explain how meiosis halves the chromosome number, and why this is necessary for sexual reproduction
Meiosis is the nuclear division that halves chromosomes # when sperm and egg meet - restores # of chromosomes at fertilization
protooncogenes
Normal cellular genes that regulate cell proliferation and differentiation that can become oncogenes.
Benign
Not dangerous (warts)
How does mitosis maintain the chromosome number?
Parent cell (46 chrom) divides, both daughter cells have 46 sister chromatids, then separated with anaphase, and packaged into 2 new cells
Malignant tumor
Progressively worsens and is dangerous to health because it disrupts functions of tissues
Germ cells
Reproductive cells that give rise to sperm and ovum (form gametes)
The time of DNA replication
S
Second division seperates
SISTER chromatids
Explain the random nature of chromosome segregation during gamete formation, and its significance in terms of genetic variation.
Spindle randomly segregates homologous chromosomes
What is the function of microtubules in mitosis?
Spindles reach to each sister chromatid and separates them into individual chromosomes
G1 phase
The first gap, or growth phase, of the cell cycle. Metabolic activities, most cells remain in this phase forever .
S phase
The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.
Sister chromatids are identical DNA molecules. T/F?
True
homologus chromosomes
Two of the same type of chromosomes, each coming from a different parent (Pair of chromosomes) chromosomes that are similar in size, shape, genes, and band patterns.
Gametes
a mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote.
prophase 2
a spindle forms in 2 cells
Mitosis
cell division in which the nucleus divides into nuclei containing the same number of chromosomes
interphase
chromosomes become duplicated
Diploid (2n)
containing two complete sets of chromosomes, one from each parent.
Germ cell
creates gametes through meiosis
cytokinesis in plant cells
divide from inside out using a cell plate in middle of cell
Cytokinesis
division of the cytoplasm to form two separate daughter cells (cytoplasmic division)
Prophase
first and longest phase of mitosis, during which the chromosomes become visible, nuclear envelop dissolves, spindle forms
Oncogenes
genes that cause cancer by blocking the normal controls on cell reproduction gene that has mutated which changes normal cells to tumor cells
Haploid (1n)
having a single set of unpaired chromosomes
prophase 1
homologous chromosome pairs associate associate and crossing over occurs
Telophase
last phase of mitosis when chromosomes reach opposite sides of the cell and loosen up. Mitosis ends when new nuclear envelope forms around each cluster of chromosomes.
asexual reproduction
process of reproduction involving a single parent that results in offspring that are genetically identical to the parent (genetic clone)
Metaphase
second phase of mitosis, during which the chromosomes line up across the center of the cell (META = MIDDLE)
anaphase 2
sister chromatids separate and move to opposite poles
G2 phase
stage of interphase in which cell duplicates its cytosol and organelles (PROTEING SYNTHESIS) (needed for cell division
Anaphase
the third phase of mitosis, during which the chromosome pairs (sister chromatids) separate and move toward opposite poles, creating individual, unduplicated chromosomes (ANA=APART)
