Concept explainers
- a. How many chromosomes are in your somatic cells?
- b. How many chromosomes are in your gametes?
- c. How many chromatids are in one of your somatic cells that has duplicated its chromosomes prior to mitosis?
a.
To determine: The number of chromosomes in an individual’s somatic cell.
Introduction: Chromosomes are present in both prokaryotes and eukaryotes and make up the genetic material of an organism. Chromosomes are thin, thread-like structures visible at time of cell division. Chromosomes are actually DNA in compacted form that is held together by basic proteins known as histones.
Explanation of Solution
The chromosomes are diploid (2n) in number in the nucleus of somatic cells. Diploid refers to two sets of chromosomes in the same nucleus. Each somatic cell in humans consists of 46 chromosomes, which are two sets of 23 chromosomes each (maternal and paternal set). Therefore, an individual’s somatic cell contains 23 pairs that are 46 (2×23) chromosomes.
The number of chromosomes in an individual’s somatic cells is 46.
b.
To determine: The number of chromosomes in an individual’s gamete.
Introduction: Chromosome is a thread-like appearance of the nucleic acids and protein molecules present in the nucleus of various cells. Chromosome mainly contains the gene that bears the genetic information of one individual.
Explanation of Solution
The chromosome number explains the precise number of chromosomes present in specific species. In sexually reproducing organisms, gametes mainly contain haploid (n) number of chromosomes. Therefore, an individual’s gamete contains 23 chromosomes. The haploid number of chromosomes is produced during meiosis stage of cell division.
The number of chromosomes in an individual’s gamete is 23.
c.
To determine: The number of chromatids in an individual’s somatic cell that has duplicated its chromosomes prior to mitosis.
Introduction: Deoxyribonucleic acid (DNA) is the genetic material carried by every eukaryotic organism. Every DNA is made up of a pair of condensed chromatid subunits, and they are held together at a region called centromere.
Explanation of Solution
The number of chromosomes in an individual’s somatic cell is 46. The 46 chromosomes duplicate during the S phase of interphase prior to the process of mitosis. Therefore, 92 chromatids are present in an individual’s somatic cell that has duplicated its chromosomes prior to mitosis.
The number of chromatids in an individual’s somatic cell that has duplicated its chromosomes prior to mitosis is 92.
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Chapter 12 Solutions
Study Guide for Campbell Biology
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- If a cell with 24 chromosome pairs underwent meiosis, how many total chromatids would be in each gamete? What are three (3) differences between mitosis and meiosis?arrow_forwardConsider a diploid organism with 18 chromosomes. Answer each question on a per cell basis. How many chromosomes are there during metaphase? How many functional centromeres are there during anaphase? How many chromosomes are there during telophase I after cytokinesis? How many chromosomes are there during prophase II? How many chromatids are there in anaphase II? How many kinds of chromosomes are there?arrow_forward1) What phase of mitosis is this? Answer: 2) What is the indicated structure 1? select one. a. chromosome b. chromosome with two sister chromatids c. centrioles/centrosome d. spindle fibres e. metaphase plate 3)If the diploid (2n) number of this cell is 8 how many chromosomes are present? 4) If the diploid (2n) number of this cell is 8 how many sister chromatids are present? 5) If the diploid (2n) number of this cell is 8 how many homologous pairs are present?arrow_forward
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