Cell Division in Biology

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What is the primary role of cell division in the lives of organisms?

To regulate cellular responses
To produce energy for the cell
To reproduce their own kind (correct)
To maintain cellular structure

What is the result of cell division in terms of genetic identity?

Daughter cells are genetically similar but not identical to the parent cell
Daughter cells are genetically identical to each other and the parent cell (correct)
Daughter cells are genetically identical to each other but not to the parent cell
Daughter cells are genetically different from the parent cell

What is the difference between asexual and sexual reproduction in terms of genetic inheritance?

Asexual reproduction produces offspring with genes from one parent, while sexual reproduction produces offspring with genes from multiple parents
Asexual reproduction produces offspring with genes from multiple parents, while sexual reproduction produces offspring with genes from one parent
Asexual reproduction produces offspring with unique genes, while sexual reproduction produces offspring with identical genes
Asexual reproduction produces offspring with identical genes, while sexual reproduction produces offspring with unique genes (correct)

What is the characteristic of the chromosome of a prokaryote?

Single circular DNA molecule (B) Signup and view all the answers

What is the process by which prokaryotes reproduce?

Binary fission (D) Signup and view all the answers

What is the purpose of cell division in multicellular organisms?

To grow and develop from a fertilized egg (C) Signup and view all the answers

What is the characteristic of the chromosome replication process in E. coli cells?

Beginning at a single origin of replication (B) Signup and view all the answers

What is the primary difference between somatic cells and gametes in terms of their chromosomes?

Somatic cells have a different number of chromosomes than gametes (B) Signup and view all the answers

What is the function of proteins in eukaryotic chromosomes?

To maintain chromosome structure and control gene activity (B) Signup and view all the answers

What happens to the chromatin in eukaryotic cells before they divide?

It becomes highly compact and visible with a microscope (B) Signup and view all the answers

What is the result of the separation of sister chromatids during cell division?

Two identical daughter cells with the same number of chromosomes (D) Signup and view all the answers

What is the cell cycle in eukaryotic cells?

An ordered sequence of events that extends from the time a cell is first formed from a dividing parent cell until its own division (D) Signup and view all the answers

What is the primary function of the mitotic phase in cell division?

Division of the nucleus (D) Signup and view all the answers

Which stage of meiosis is characterized by the separation of sister chromatids?

Anaphase II (C) Signup and view all the answers

What is the term for the position of a gene on a chromosome?

Locus (C) Signup and view all the answers

What is the result of meiosis in diploid organisms?

Four haploid gametes (C) Signup and view all the answers

What is the purpose of crossing over in meiosis?

To increase genetic variation (D) Signup and view all the answers

What is the term for the process of cell division that produces two genetically identical diploid cells?

Mitosis (A) Signup and view all the answers

What is the term for the stage of the cell cycle where the cell grows and prepares for cell division?

Interphase (B) Signup and view all the answers

What is the result of the fusion of a haploid sperm and a haploid egg during fertilization?

A diploid zygote (C) Signup and view all the answers

Which type of cell division is preceded by the duplication of chromosomes?

Both mitosis and meiosis (B) Signup and view all the answers

What is the term for the division of the cytoplasm in cell division?

Cytokinesis (D) Signup and view all the answers

What is the result of the fusion of 2 gametes, each with 8.4 million possible chromosome combinations from independent assortment?

A zygote with 70 trillion diploid combinations (A) Signup and view all the answers

What is the minimum number of crossover events that occur per chromosome pair during meiosis in humans?

0 (D) Signup and view all the answers

What is the result of nondisjunction during meiosis I?

gametes with an altered number of chromosomes (C) Signup and view all the answers

What is the characteristic of a person with trisomy 21?

All of the above (D) Signup and view all the answers

What is the most common human chromosome abnormality?

Trisomy 21 (D) Signup and view all the answers

Why do sex chromosome abnormalities seem to have a lower impact on survival compared to autosomal abnormalities?

The Y chromosome is smaller than the X chromosome (C) Signup and view all the answers

What is the result of a reciprocal translocation?

Attachment of a segment to a nonhomologous chromosome (C) Signup and view all the answers

What is the minimum number of chiasmata per chromosome pair during meiosis?

0 (B) Signup and view all the answers

What is the effect of crossing over on genetic variation?

It increases genetic variation (B) Signup and view all the answers

What is the result of independent assortment of chromosomes?

2^n possible combinations of chromosomes (B) Signup and view all the answers

What is the fundamental purpose of cell division in living organisms?

Cell division is essential for reproduction, growth, and cell renewal and repair in living organisms. Signup and view all the answers

How does the process of cell division ensure genetic identity in the resulting daughter cells?

Cell division ensures genetic identity by duplicating the chromosomes and sorting the new sets of chromosomes into the resulting pair of daughter cells. Signup and view all the answers

What is the key difference between asexual and sexual reproduction in terms of genetic variation?

Asexual reproduction produces offspring with no genetic variation, while sexual reproduction produces offspring with unique combinations of genes from two parents. Signup and view all the answers

What is the characteristic of the chromosome structure in prokaryotic cells?

The chromosome of a prokaryote is typically a single circular DNA molecule. Signup and view all the answers

What are the three main purposes of cell division in multicellular organisms?

Cell division is necessary for growth, cell renewal and repair, and production of gametes (sperm and egg cells) in multicellular organisms. Signup and view all the answers

Why is cell division a critical component of an organism's ability to reproduce its own kind?

Cell division enables organisms to reproduce their own kind by producing genetically identical daughter cells that can grow and develop into new individuals. Signup and view all the answers

How do bacterial chromosomes replicate, and what is the outcome of this process?

Bacterial chromosomes replicate by beginning at the origin of replication, and the cell elongates while the chromosome is replicating. The outcome is two daughter chromosomes that actively move apart, and the plasma membrane pinches inward, dividing the cell into two. Signup and view all the answers

What is the difference between somatic cells and gametes in terms of their chromosomes, and how do they divide?

Somatic cells are diploid (2n) and have two sets of chromosomes, whereas gametes are haploid (n) and have half as many chromosomes as somatic cells. Somatic cells divide by mitosis, and gametes divide by meiosis. Signup and view all the answers

What are the key components of eukaryotic chromosomes, and how do they prepare for cell division?

Eukaryotic chromosomes are composed of chromatin, consisting of one long DNA molecule and proteins that help maintain the chromosome structure and control gene activity. To prepare for division, chromatin becomes highly compact and visible with a microscope. Signup and view all the answers

What is the result of chromosome duplication in eukaryotic cells, and how do the sister chromatids behave during cell division?

Chromosome duplication in eukaryotic cells results in sister chromatids, which are joined together along their lengths by cohesins and are cinched especially tightly at the centromere. During cell division, the sister chromatids separate from each other and sort into separate daughter cells. Signup and view all the answers

What is the cell cycle, and what are the two stages involved?

The cell cycle is an ordered sequence of events that extends from the time a cell is first formed from a dividing parent cell until its own division. The two stages are the growing phase and the division phase. Signup and view all the answers

What is the difference between prokaryotic and eukaryotic cells in terms of their chromosome structure and replication?

Prokaryotic cells have a single, circular chromosome, whereas eukaryotic cells have multiple, linear chromosomes with more complex structures. Prokaryotic cells replicate their chromosomes in a simpler process compared to eukaryotic cells. Signup and view all the answers

What is the significance of the prophase stage in mitosis and meiosis?

In prophase, chromatin condenses into chromosomes, and the nuclear envelope breaks down. This stage prepares the cell for chromosome separation in both mitosis and meiosis. Signup and view all the answers

How do homologous chromosomes contribute to genetic variation in offspring?

Homologous chromosomes contribute to genetic variation through crossing over, which increases genetic diversity by creating new combinations of alleles. Signup and view all the answers

What is the difference between the metaphase stage in mitosis and meiosis I?

In mitosis, chromosomes line up at the metaphase plate as identical sister chromatids. In meiosis I, pairs of homologous chromosomes line up at the metaphase plate. Signup and view all the answers

How do the two consecutive cell divisions in meiosis contribute to genetic variation?

The two consecutive cell divisions in meiosis (meiosis I and meiosis II) increase genetic variation by allowing for independent assortment and crossing over, resulting in unique haploid gametes. Signup and view all the answers

What is the role of the centromere in chromosome separation during mitosis and meiosis?

The centromere is the specialized region on a chromosome that attaches to microtubules, allowing for proper chromosome separation during mitosis and meiosis. Signup and view all the answers

How do the life cycles of diploid and haploid organisms differ?

Diploid organisms have a life cycle that begins with a diploid zygote, followed by mitosis and growth, whereas haploid organisms have a life cycle that begins with a haploid gamete and involves meiosis to produce haploid offspring. Signup and view all the answers

What is the significance of the anaphase stage in mitosis and meiosis?

In anaphase, sister chromatids or homologous chromosomes separate, leading to the distribution of genetic material to daughter cells in mitosis and meiosis. Signup and view all the answers

How do the mechanisms of mitosis and meiosis differ in terms of genetic identity and variation?

Mitosis produces genetically identical diploid cells, whereas meiosis produces genetically unique haploid gametes, resulting in genetic variation in offspring. Signup and view all the answers

What is the role of cytokinesis in the cell division process?

Cytokinesis is the division of the cytoplasm, which completes the cell division process in both mitosis and meiosis. Signup and view all the answers

How do the three mechanisms of genetic variation (crossing over, independent assortment, and random fertilization) contribute to genetic diversity in offspring?

These mechanisms contribute to genetic diversity by increasing the number of possible genetic combinations in offspring, resulting in genetic variation and diversity. Signup and view all the answers

How does the process of independent assortment of chromosomes contribute to genetic variation, and what is the approximate number of possible diploid combinations resulting from this process?

Independent assortment of chromosomes contributes to genetic variation by allowing each pair of chromosomes to align independently at the metaphase plate, resulting in 2^n possible combinations of chromosomes. This, combined with crossing over, produces approximately 70 trillion possible diploid combinations. Signup and view all the answers

Describe the significance of crossing over in meiosis, including how it increases genetic variation and what is the average number of crossover events per chromosome pair in humans?

Crossing over, or genetic recombination, increases genetic variation by exchanging corresponding segments between nonsister chromatids of homologous chromosomes. In humans, an average of 1-3 crossover events occur per chromosome pair, further increasing genetic variability. Signup and view all the answers

What is the result of nondisjunction during meiosis, and how does it affect the resulting gametes?

Nondisjunction during meiosis results in the failure of chromosomes or chromatids to separate normally, producing abnormal gametes with altered chromosome numbers. This can lead to zygotes with abnormal chromosome numbers, resulting in genetic disorders or abnormalities. Signup and view all the answers

Describe the characteristics of trisomy 21, including the symptoms and the incidence of this condition in relation to the age of the mother.

Trisomy 21, also known as Down syndrome, is a genetic disorder characterized by the inheritance of three copies of chromosome 21. Symptoms include characteristic facial features, short stature, heart defects, susceptibility to respiratory infections, and varying degrees of developmental disabilities. The incidence of trisomy 21 increases with the age of the mother. Signup and view all the answers

Explain why sex chromosome abnormalities seem to have a lower impact on survival compared to autosomal abnormalities, and describe the most common human sex chromosome abnormalities.

Sex chromosome abnormalities seem to have a lower impact on survival due to the small size of the Y chromosome and X chromosome inactivation. The most common human sex chromosome abnormalities include a single Y chromosome producing 'maleness' and the absence of a Y chromosome yielding 'femaleness'. Signup and view all the answers

Describe the types of alterations in chromosome structure that can cause birth defects and cancer, and provide an example of each.

Alterations in chromosome structure that can cause birth defects and cancer include inversions, deletions, duplications, and reciprocal translocations. For example, an inversion can cause a reversal of a chromosome segment, while a deletion can result in the loss of a chromosome segment. Signup and view all the answers

What is the relationship between the number of crossover events and genetic variation, and how does this impact the uniqueness of an individual's genetic identity?

The number of crossover events increases genetic variation by allowing for more possible combinations of genes. This, combined with independent assortment, results in a unique genetic identity for each individual. Signup and view all the answers

Describe the difference between genetic variation resulting from independent assortment and that resulting from crossing over, and explain how these processes interact to produce genetic diversity.

Independent assortment contributes to genetic variation by allowing each pair of chromosomes to align independently, while crossing over increases genetic variation by exchanging corresponding segments between nonsister chromatids. These processes interact to produce genetic diversity by allowing for a vast number of possible combinations of chromosomes and genes. Signup and view all the answers

How does the process of meiosis contribute to genetic variation, and what is the significance of this variation in the context of evolutionary biology?

Meiosis contributes to genetic variation through the processes of independent assortment and crossing over, resulting in a unique genetic identity for each individual. This genetic variation is essential for the survival and adaptation of a species, and is the raw material for natural selection to act upon. Signup and view all the answers

What is the significance of genetic variation in the context of human health, and how do mechanisms such as independent assortment and crossing over impact the risk of genetic disorders?

Genetic variation is essential for human health, as it allows for adaptation to changing environments and provides a buffer against genetic disorders. Mechanisms such as independent assortment and crossing over increase genetic variation, which can reduce the risk of genetic disorders by providing a diverse range of genetic combinations. Signup and view all the answers