Concept explainers
- a. How many chromosomes are there in the somatic cells of an animal in which 2n = 14? __________How many chromosomes are in its gametes? _________
- b. If n = 14, how many chromosomes are there in diploid somatic cells? _______ How many sets of homologous chromosomes are in the gametes?
- c. If 2n = 28, how many chromatids are there in a cell after chromosome duplication has occurred prior to cell division? ___________ What is the difference between sister chromatids and nonsister chromatids?
a.
To determine: The number of chromosomes present in a somatic cell of an animal in which 2n=14.
Introduction: Chromosomes are long thread like structures present in all cells of the body. These chromosomes contain coded genetic materials in the form of genes and that are transmitted to the succeeding generations by the process of cell division. A diploid cell contains two set of chromosomes, whereas a single set of chromosome is present in haploid cells.
Answer to Problem 1IQ
The number of chromosomes present in the given somatic animal cell is 14.
Explanation of Solution
Somatic cells include all the body cells except the gametes (sperms and ova). Under normal conditions, all the somatic cells exist in a diploid form. It is given that the animals have (2n=14) and (2n) represents the diploid condition of the cell. It is given that the cell is somatic and hence, it is also diploid. Thus, the number of chromosomes present in the given somatic animal cell is 14.
To determine: The number of chromosomes present in the gamete cells of an animal is 2n=14.
Answer to Problem 1IQ
The number of chromosomes present in the cell’s gamete is 7.
Explanation of Solution
Gametes are the reproductive cells and include the sperms and ova. Under normal conditions, all the gametes exist in a haploid condition. It is given that 2n=14 where (2n) indicates diploid condition of the cell. Therefore, the gametes that are haploid have 7 chromosomes in its cell.
b.
To determine: The number of chromosomes present in a diploid somatic cell is n=14.
Introduction: Somatic cells include all the body cells except the gametes. Gametes include the reproductive cells, which are the sperms and ova.
Answer to Problem 1IQ
The number of chromosomes present in a diploid somatic cell, when n=14 is 28.
Explanation of Solution
It is given that n=14 and (n) indicates the haploid condition and when the cells are diploid, the number of chromosomes is 28 (since n=14, 2n=28). Therefore, the diploid somatic cell has 28 chromosomes.
To determine: The number of set of the homologous chromosomes present in the gametes.
Answer to Problem 1IQ
The set of homologous chromosomes present in the gamete is 1.
Explanation of Solution
Homologous chromosomes are the pair of chromosomes containing one maternal and one paternal chromosome. Homologous chromosomes are paired chromosomes that are identical in length, centromere location, and the gene loci but the sequence of the gene varies. The gametes are haploid and hence, they possess only a single set of chromosomes that they contribute it during the fertilization. Therefore, the set of homologous chromosomes present in the gamete is 1.
c.
To determine: The number of chromatids present after the occurrence of duplication of the chromosome prior to the cell division in a cell containing 2n=28.
Introduction: Chromosomes are long thread like structures present in the cell. Each chromosome constitutes two chromosomal arms that are linked together by the centromere. The coded information in the form of genes is arranged in the chromatids.
Answer to Problem 1IQ
The number of chromatids present in the cell after the duplication of chromosome had occurred prior to cell division, when 2n=28 is 56.
Explanation of Solution
If the chromosomes undergo duplication before the onset of cell division, the number of chromosomes in the cell doubles. Since each chromosome has two chromatids, the number of chromatids when 28 chromosomes are present in the cell 56.
To differentiate: Sister chromatids from non-sister chromatids.
Explanation of Solution
Criteria | Sister chromatids | Non-sister chromatids |
Formation | Sister chromatids are formed when the chromosome undergoes duplication during the S phase of interphase. | Non-sister chromatids occur on different chromosomes of the homologous chromosomes. |
Centromere | They are joined by the centromere at the center and all along their length by cohesive proteins. | Since they are present in different chromosomes, they are not linked by the centromere. |
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Chapter 13 Solutions
Study Guide for Campbell Biology
- A. In 1952, the nucleus of a _______________________ embryo was placed into a donor cell. Was the embryo cloned successfully? ___________________ B. Can the nucleus of an adult cell be injected into an egg cell and produce a clone?arrow_forwarda. What is the diploid number of chromosomes for a human? b. What is the haploid number of chromosomes for a human? Which cells are considered diploid, gametes or somatic cells? C. d. Which cells are considered haploid, gametes or somatic cells?arrow_forwarda. What type of cell division mitosis, meiosis I or meiosis II is shown in this figure? b. What is the diploid number of this organism? c. Provide labels for (i) and (ii)arrow_forward
- . Complete the following statements using as many ofthe following terms as are appropriate: mitosis, meiosis I (first meiotic division), meiosis II (second meioticdivision), and none (not mitosis nor meiosis I normeiosis II).a. The spindle apparatus is present in cells undergoing_____.b. Chromosome replication occurs just prior to _____.c. The cells resulting from _____ in a haploid cellhave a ploidy of n.d. The cells resulting from _____ in a diploid cellhave a ploidy of n.e. Homologous chromosome pairing regularly occursduring _____.f. Nonhomologous chromosome pairing regularlyoccurs during _____.g. Physical recombination leading to the productionof recombinant progeny classes occurs during_____.h. The separation of sister centromeres occurs during_____.i. Nonsister chromatids are found in the same cellduring _____.arrow_forwardPART 4: Indicate whether each statement refers to mitosis (MI), meiosis (ME), both (B) or neither (N) _______________ Tetrads are formed _______________ Division starts with haploid cells _______________ Chromosome number is reduced _______________ Amount of DNA in cells is reduced _______________ Results in the formation of diploid cells _______________ Sister chromatids are separated _______________ Leads to genetic variation _______________ Is a part of asexual reproduction _______________ Homologous pairs are separated _______________ Results in the formation of 4 diploid cellsarrow_forwardWhich of the following terms describes the process of homologous chromosomes failing to separate correctly during meiosis?A. Chromatid adhesion syndromeB. NondisjunctionC. AmetaphasiaD. Anti-anaphasearrow_forward
- The image represents a cell in ___________________ of Meiosis. a) anaphase I b) anaphase IIarrow_forwardWhen does DNA replication take place regarding meiosis? DNA replication___ (select one) A. Occurs between meiosis I and meiosis II B. occurs during Prophase I C. occurs before meiosis I begins D. does not take place in cells best into undergo meiosisarrow_forwardOogenesis is the process of female gamete (ovum or egg) production in animals. Spermatogenesis is the process of male gamete (sperm) production in animals. Although both processes produce gamete(s), there are distinct similarities and differences between the two. Compare and contrast oogenesis to spermatogenesis by drawing a diagram showing the two processes. In your hand-drawn diagrams, be sure to include when the processes of mitosis, meiosis I and meiosis II are occurring identify each germ cell structure and its ploidy highlight 4 differences between the two processesarrow_forward
- During ______________, each chromosome condenses and is composed of ______________ joined sister ______________ that are genetically ______________. Question 10 options: metaphase; two; chromatids; identical telophase; three; chromospheres; unique None of the other answers are correct. cytokinesis; two; centrioles; unique anaphase; four; centrioles; identical prophase; two; chromatids; identical the S Phase; three; chromospheres; uniquearrow_forwardCucumis sativus (cucumber) is a diploid plant with 7 chromosome pairs. Determine the following as its cell divides by mitosis or meiosis: number of centromeres at Metaphase I _______________ number of univalents at Anaphase I (per pole) _______________ number of chromatids at Prophase _______________ chromosome number at Metaphase _______________ chromosome number at Telophase I (after cytokinesis) _______________arrow_forwardMatch the stage of meiosis to its description. Watch for "cell" versus "cells". Singular versus plural is a clue that will help you pick the right roman numeral. homologous chromosomes line up next to each other as tetrads along the mid-line of the cell DNA condenses, tetrads form as homologous chromosomes come together and exchange DNA parts in crossing over, nuclear membrane disintegrates A. Early Interphase B. Late Interphase one of each homologous pair reaches the end of the cell, new nuclear membranes form, and the cell membrane begins to pinch in C. Prophase I v DNA condenses in two cells, nuclear membranes disintegrate D. Metaphase I the copies of the chromosomes (daughter chromosomes formerly known as sister chromatids) split apart and move towards the ends of two cells E. Anaphase I F Telophase I the cell divides into two cells, chromosomes decondense G. Interkinesis tetrads separate and homologous chromosomes begin to move in opposite directions in a cell H. Prophase II v DNA…arrow_forward
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