ch 8 mastering biology

Part C During prophase I of meiosis,

homologous chromosomes stick together in pairs.

Origins of Genetic Variation

independent assortment of chromosomes, crossing over, random fertilization

Mitosis and Cytokinesis Animation Part A Nucleoli are present during _____.

interphase

Part B A cell preparing to undergo meiosis duplicates its chromosomes during

interphase

Part D During _____, the cell carries out its normal functions and the chromosomes are thinly spread out throughout the nucleus.

interphase

Part E Spindle fibers attach to kinetochores during ___

prometaphase

Part C Chromosomes become visible during _____.

prophase

Part E Synapsis occurs during _____.

prophase I

Part D The correct order of events during meiosis is

prophase I, metaphase I, anaphase I, telophase I, cytokinesis, meiosis II.

Part E 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? View Available Hint(s)

prophase I.

Part I During _____ a spindle forms in a haploid cell.

prophase II

Mitosis occurs in _____; meiosis occurs in _____.

somatic or body cells ... germ cells in the testes or ovaries

Part B Cytokinesis often, but not always, accompanies _____.

telophase

Part E 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 arewitnessing _____.

telophase

Part D At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids.

telophase I

Part H At the end of _____ and cytokinesis there are four haploid cells.

telophase II

Part E Why is the "personalized care" plan described in the video, in which treatments are tailored for each individual, much more promising than previous treatment plans?

the genetic mutations that cause cancer vary from patient to patient

Imagine I've taken a snapshot of the chromosomes in a hypothetical cell. Two chromosomes lined up. You and your twin and your friends and her twin. Part of that snapshot looks like this. What stage of the lifecycle must that cell be in?

the start of meiosis I

Meiosis Animation Part A Meiosis I produces _____ cells, each of which is _____.

two ... haploid

Part F During prophase a homologous pair of chromosomes consists of _____.

two chromosomes and four chromatids

Part A Can you identify the major theme illustrated by each of the following examples? If necessary, you may review the themes in Chapter 1 of your book. Match the themes on the left with the examples on the right. Not all themes will be used.

*During cell division, each daughter cell receives one identical set of chromosomes from the original parent cell. --Information flow-- *Cancer cells do not respond normally to the specialized proteins that control the cell cycle; they divide excessively and may invade other tissues of the body. --Interactions within biological systems-- *Sexual reproduction may enhance fitness by producing offspring of varied genetic makeup, speeding adaptation to a changing environment. ----Evolution-- *Long molecules of DNA can fit into the tiny nucleus because within each chromosome the DNA is packed into an elaborate, multilevel system of coiling and folding.--Relationship of structure to function--

Part B During _____ both the contents of the nucleus and the cytoplasm are divided.

- The mitotic phase encompasses both mitosis and cytokinesis.

Part B Which events occur during prophase? Check all that apply.

-Chromosomes condense and are attached to spindle fibers. -The nuclear envelope breaks down.

Part B - Thinking critically Use the graph and your knowledge of Down syndrome to select the three true statements.

-The incidence of Down syndrome in infants born to mothers under the age of 35 is less than 0.5%-Down syndrome is caused by a trisomy of chromosome 21.-The risk of having a baby with Down syndrome more than doubles for 45-year old mothers compared to 40-year old mothers.

Part C During _____ the cell grows and replicates both its organelles and its chromosomes.

-These are the events of interphase.

Mitosis Part A In sexually reproducing multicellular organisms, the main functions of mitosis are _____.

-tissue repair/replacement of damaged cells -growth and developmen

Part A - Stages of the cell cycle Drag the labels onto the diagram to identify the stages of the cell cycle.

1. most of the cells life is spent in interphase 2. in phosphase microtubules form the mitototic spindle 3. at metaphase, the mitotic spindle is fully formed 4. in anaphase, sister chromatides separate 5. in telophase chromosomes become less condenced

Can you match the terms associated with cancer to their descriptions? Part A Drag the terms on the left to the appropriate blanks on the right to complete the sentences.

1.. A---benign tumor--is a lump of abnormal cells that, although growing out of control, remains at its original site. 2. A--malignant tumor--is an abnormally growing mass of cells that is actively spreading through the body. 3. --Metastasisis-- the spread of cancer cells from their site of origin to other sites in the body. 4. An individual with a malignant tumor is said to have--cancer--.

Imagine you found a hypothetical organism. You examine one of its gametes and you see that it contains 5 chromosomes. How many chromosomes will one of its body cells contain just before mitosis begins?

10

Everyday Biology: Are Fruit Flies the Key in the Fight Against Cancer? Part A When did the United States declare a "war on cancer" by passing the National Cancer Act?

1971

Interpreting Data: Down Syndrome Part A - Interpreting the graph On average, what percentage of infants born to 45-year-old mothers have Down syndrome?

3%

Part B Which of the following is closest to the current average annual death rate from cancer in the United States?

580 thousand

Part D The sister chromatids separate and begin moving toward opposite poles of the cell during which phase of mitosis?

Anaphase

Part B Which of these gametes contains one or more recombinant chromosomes?

B an C contain two or more recombinant chromosomes. Each are composed of material derived from both parents

Part G Which of the following best describes the advantages of the personalized care technique described in the video?

Fruit flies make excellent models because we can create a strain of flies with a specific type of tumor, then raise thousands of flies in order to test the effects of medications.

Part B Which of the following is true about the human life cycle?

Gametes are produced by meiosis.

Part C Select all the true statements about human gametes.

Meiosis in ovaries produces haploid eggs.Meiosis in testes produces haploid sperm.Both eggs and sperm contribute 23 chromosomes to the zygote.

Part C The chromosomes line up in the center of the cell during which phase of mitosis?

Metaphase

Part B The centrosomes move away from each other and the nuclear envelope breaks up during which phase of mitosis?

Prophase

Part E The chromosomes arrive at the poles and nuclear envelopes form during which phase of mitosis?

Telophase

BioFlix Quiz: Mitosis Part A What must happen before a cell can begin mitosis?

The chromosomes must be duplicated

BioFlix Activity: Mitosis -- The Cell Cycle 2 of 10 Review Can you label the phases of the cell cycle? To review a crucial phase of the cell cycle, watch this BioFlix animation: Mitosis. Part A - The cell cycle 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 phases.

a g1 phase b. s phase c. interphase d. g2 phase e. mitotic m phase f. mitosis g. cytokinesis

The Human Life Cycle 3 of 16 Review Watch this video and then answer the questions. Part A The figure shows the human life cycle. Can you identify the structures and processes? Drag the labels to their appropriate locations on the figure. Pink labels represent structures, and blue labels represent processes.

a- haploid gametes b. egg cell c. sperm cell d. fertilization e. diploid zygote f. mitosis g. multicellular diploid adults h. meiosis

Part A - Meiosis concept map Drag the terms to complete the concept map below.

a. diploid organisms b. haploid gametes c. meiosis 2 d. maternal chromosomes e. crossing over occurs f. sister chromatids separate

Learning through Art: Human Life Cycle 4 of 16 Complete Review Can you correctly label this diagram of the human life cycle? Part A Part complete 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

Learning through Art: Chromosomes 2 of 16 Review Can you correctly label these images of chromosomes? Part A Drag the labels to the correct locations on these images of human chromosomes.

a. homologous b. centromere c. sister chromatids d. autosomes e. sex chromosomes f. karyotype

Chapter 8-02 Connecting the Concepts: Cell Division 1 of 16 Review Can you organize these terms that describe the different kinds of cell division?

a. mitosis b. meiosis c. asexual reproduction d. somatic cells e. gametes f. sexual reproduction

BioFlix Activity: Meiosis -- Comparing Mitosis and Meiosis

a. mitosis b. prophase c. metaphase d. anaphase. telophase, & cytokinesis e. meiosis f. prophase 1 g. metaphase 1 h anaphase1, telophase 1 & cytokinesis i. meiosis 2

Can you label the events and stages of mitosis? To review the process of mitosis, watch this BioFlix animation: Mitosis. Part A - Events of mitosis 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. chromosomes separation d. nuclear envelope forming e. interphase f. prophase g. metaphase h. anaphase i. telophase and cytokenesis

BioFlix Activity: Meiosis -- Chromosome Structure Review Can you identify the structures of a chromosome? To review chromosome structure, watch this BioFlix animation: Meiosis. Part A - Homologous chromosomes Drag the labels onto the diagram to identify the various chromosome structures.

a. pair of homologous chromosomes b. centromere c. sister chromatides

Learning through Art: Chromosome Packing Can you correctly label the structures in this diagram that summarizes chromosome packing?

a.) Histone b.) Nucleosome c.) Supercoil d.) Chromosome e.) Chromati

Part D Centromeres divide and sister chromatids become full-fledged chromosomes during _____.

anaphase

Part F Homologous chromosomes migrate to opposite poles during _____.

anaphase I

Part C During _____ sister chromatids separate.

anaphase II

Part D Since 1991, deaths from breast and colorectal cancer in the United States are down 35%. What is the main reason for this?

better screening

Part C Based on the information in the video, which of the following correctly answers these three questions:What was the leading cause of death in the United States in the early 1970s?What is the leading cause of death in the United States today?What is predicted to be the leading cause of death in the United States 10 years from now?

cancer; cardiovascular disease; cancer

Here i am representing a duplicated chromosome. What structure is represented by my waist where I am joined to my twin?

centromere

Part F At the end of the mitotic (M) phase, the cytoplasm divides in a process called _________________.

cytokinesis

Activity: The Cell Cycle Part A Part complete Which of these phases encompasses all of the stages of mitosis?

e-This is mitosis.

Part C Cytokinesis _____.

finishes mitosis by dividing the cytoplasm and organelles of the original parent cell into two separate daughter cells

Part B Part complete Meiosis II typically produces _____ cells, each of which is _____.

four ... haploid

BioFlix Quiz: Meiosis Part A Meiosis starts with a single diploid cell and produces

four haploid cells.

Part C Fertilization joins _____ to produce a _____.

haploid gametes ... diploid zygote

Part E If it weren't for _____, chromosome number would double with every generation of sexual reproduction.

meiosis

If you look through a microscope and see a cell with chromosomes lined up two by two, what stage of cellular reproduction must you be looking at?

meiosis I only

Part G During _____ chromosomes align single file along the equator of a haploid cell.

metaphase II

Part B 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, independentof its homolog. You are witnessing _____.

metaphase of mitosis

Video Tutor Session Quiz: Mitosis vs. Meiosis Of the two processes we learned about which is going on in my hand right now?

mitosis

Part D Duplication of the chromosomes to produce sister chromatids _____.

occurs in both mitosis and meiosis

Part F Which of the following organisms would be most similar to humans in a study that involved the response of cancer cells to various medications?

primates