Significance and Application of Mitosis and Meiosis

30 Question-and-Answer flashcards reviewing definitions, processes, significance, advantages, disadvantages, and examples related to mitosis, meiosis, and asexual reproduction.

What is the primary purpose of mitosis in multicellular organisms?

Growth and repair by producing genetically identical diploid daughter cells.

What type of cells are produced at the end of mitosis and how many?

Two genetically identical diploid cells.

What major role does meiosis play in sexual reproduction?

It produces gametes with half the chromosome number, ensuring the correct chromosome number after fertilization.

How many cells result from meiosis and what is their ploidy?

Four genetically unique haploid cells.

Which phases of meiosis contribute to genetic variation and how?

Crossing over during Prophase I and independent assortment during Metaphase I shuffle genetic material.

What is the term for the pairing of homologous chromosomes during Prophase I?

Synapsis.

What structure forms during synapsis that allows crossing over?

A tetrad (bivalent).

Why are siblings genetically different despite having the same parents?

Meiosis generates unique gametes through crossing over and independent assortment, creating new allele combinations at fertilization.

Name three human tissue types that rely on mitosis for repair.

Muscle tissue, epithelial tissue, and nerve tissue (connective tissue is also acceptable).

Give an example of an organism that reproduces asexually by budding.

Hydra (or yeast).

What is binary fission and which organisms commonly use it?

A form of asexual reproduction where a single-celled organism divides into two equal cells; common in amoeba and bacteria.

Define fragmentation in asexual reproduction and provide an example.

A parent organism breaks into pieces, each growing into a new individual; e.g., starfish or planaria.

Why can asexual populations be wiped out by a single disease?

They are genetically identical, so if one individual is susceptible, all are.

What is one disadvantage of mitosis in terms of evolution?

It does not create genetic variation, limiting adaptability.

What is a major disadvantage of meiosis-linked sexual reproduction?

It requires two individuals and consumes more time and energy.

During which stage of meiosis do sister chromatids finally separate?

Anaphase II.

In mitosis, during which phase do sister chromatids separate?

Anaphase.

What key event precedes both mitosis and meiosis to ensure DNA is copied?

DNA replication during interphase (S phase).

What does “diploid” mean?

A cell containing two sets of chromosomes (2n).

What does “haploid” mean?

A cell containing one set of chromosomes (n).

What is the role of spindle fibers during cell division?

They attach to chromosomes and help segregate them to opposite poles.

How does plant asexual reproduction via runners work?

The parent plant sends out horizontal stems (runners) that develop roots and shoots forming new plants.

Which large reptile is known to reproduce asexually via parthenogenesis?

Komodo dragon.

What is cytokinesis?

The division of the cytoplasm, completing cell division after mitosis or meiosis.

Why is mitosis important for tissue regeneration after injury?

It replaces damaged or worn-out cells with identical new cells, restoring tissue function.

What organisms can produce new individuals from cuttings placed in water?

Certain plants (e.g., ivy or pothos) using mitosis for asexual reproduction.

During mitosis, what is the arrangement of chromosomes at metaphase?

Chromosomes line up single file at the cell’s equatorial plate.

What forms at the end of Telophase I in meiosis?

Two haploid cells with duplicated chromosomes.

What key feature distinguishes meiosis II from mitosis?

Meiosis II starts with haploid cells and separates sister chromatids without another round of DNA replication.

What classroom activity did students perform to compare mitosis and meiosis?

Creating a comparison chart highlighting differences and similarities.