Questions and Answers
What is the cell cycle?
What is a centromere?
Region at which sister chromatids are bound together
Define chromatid.
Single DNA molecule of two strands of duplicated DNA held together at the centromere
What does diploid mean?
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What is a gamete?
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Define a gene.
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What is a genome?
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What does haploid mean?
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Define histone.
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What are homologous chromosomes?
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What is the locus?
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What is a nucleosome?
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A diploid cell has _______ the number of chromosomes as a haploid cell.
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An organism's traits are determined by the specific combination of inherited _____.
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The first level of DNA organization in a eukaryotic cell is maintained by which molecule?
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Identical copies of chromatin held together by cohesin at the centromere are called _____.
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Compare and contrast a human somatic cell to a human gamete.
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What is the relationship between a genome, chromosomes, and genes?
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Explain how eukaryotic chromosomes can fit inside a nucleus.
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What stage of mitosis involves sister chromatids being separated?
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What does a cell plate indicate?
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Study Notes
Cell Cycle Overview
- The cell cycle consists of an ordered sequence of events between cell divisions, necessary for growth and reproduction.
Key Terms and Definitions
- Centromere: A constricted region where sister chromatids are joined, pivotal in chromosome alignment during cell division.
- Chromatid: Each of the two duplicated strands of DNA held together at the centromere; essential for proper chromosome segregation.
- Diploid (2n): Cells or organisms that carry two sets of chromosomes, typical in somatic cells.
- Gamete: A haploid reproductive cell (sperm or egg), containing one set of chromosomes.
- Gene: The basic unit of heredity, consisting of DNA sequences that encode proteins, influencing traits.
- Genome: The complete set of genetic material present in a cell or organism, encapsulating all chromosomes.
- Haploid (n): Refers to cells with a single set of chromosomes, characteristic of gametes.
- Histone: Basic proteins that play a critical role in the packaging of DNA into nucleosomes, aiding in DNA organization.
- Homologous Chromosomes: Chromosome pairs of the same morphology, each inherited from a different parent, holding similar genes.
- Locus: The specific physical location of a gene on a chromosome.
- Nucleosome: The fundamental unit of chromatin, formed by DNA wrapped around histones, facilitating compaction of genetic material.
Chromosome Characteristics
- A diploid cell carries twice the number of chromosomes compared to a haploid cell, emphasizing genetic diversity through sexual reproduction.
- Traits in an organism are influenced by the inherited genes from both parents, as part of their DNA.
- Histones are crucial for the initial stage of DNA configuration in eukaryotic cells.
Cellular Division Phases
- Sister chromatids refer to identical copies of chromatin linked at the centromere and separated during mitosis.
- Human somatic cells harbor 46 chromosomes (22 pairs of autosomes and 2 sex chromosomes), while human gametes contain 23 chromosomes, reflecting their diploid and haploid states, respectively.
Genetic Structure Relationships
- The genome is the collective total of an organism’s chromosomes; each chromosome comprises numerous genes with coding and non-coding DNA.
Chromatin Structure and Function
- Eukaryotic chromosomes exceed typical cell length and are compacted through wrapping around histones to form nucleosomes, further organized into fibers.
- The mechanism of chromatin condensation is essential for effective chromosome segregation during division.
Summary of Genetic Concepts
- Prokaryotes possess a singular circular chromosome, while eukaryotes have multiple linear chromosomes encased within a nucleus.
- In human somatic cells, chromosomes are categorized as 22 pairs of autosomes plus 2 sex chromosomes, indicating diploid nature.
- Mitosis requires chromosomes to be highly condensed for accurate segregation, achieved through various proteins aiding in DNA organization.
Mitosis Stage
- Anaphase: A critical phase in mitosis where sister chromatids are pulled apart, ensuring each new daughter cell receives an identical set of chromosomes.
Additional Cell Cycle Concept
- Cell Plate: A structure involved in plant cell division, forming during cytokinesis, aiding in the separation of daughter cells.
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Description
This quiz features a set of flashcards covering key terms related to the cell cycle. Each card includes a definition to help reinforce your understanding of important concepts like centromeres and chromatids. Perfect for students revising cellular biology topics.