D2.1 Cell and Nuclear Division Flashcards
What is the basic structural unit of all living organisms?
Cells
Cells are the fundamental building blocks of all living things.
What term is used to refer to the parent cell in cell division?
Mother cell
The terms ‘mother’ and ‘daughter’ are identifiers, with no implication of gender.
What process do prokaryotic cells, such as bacteria, use to divide?
Binary fission
What type of nuclear division do eukaryotic cells undergo?
Mitosis
What type of nuclear division creates gametes in eukaryotic organisms?
Meiosis
What is cytokinesis?
The process of splitting the cytoplasm between daughter cells
How do animal cells achieve cytokinesis?
Through the formation of a contractile ring of actin and myosin proteins
What structure forms in plant cells during cytokinesis?
Cell plate
What is the significance of equal cytoplasmic division in cytokinesis?
Ensures both daughter cells are the same size and have the same structure and function
What is oogenesis?
The process of producing mature egg cells or ova in humans
What happens to the first polar body during oogenesis?
It usually disintegrates and is re-absorbed by the body
What is budding in yeast?
A type of asexual reproduction involving the outgrowth of a genetically identical daughter cell
What is the role of mitosis in eukaryotic cells?
Produces diploid daughter cells for growth and repair
What type of cells does meiosis produce?
Haploid genetically unique daughter nuclei
What is the significance of crossing over in meiosis?
It leads to genetic variation in the daughter cells
What must occur before mitosis or meiosis?
DNA replication
What are sister chromatids?
Two genetically identical elongated DNA molecules held together by a centromere
What is the basic building block of chromatin?
Nucleosome
What role do microtubules play in cell division?
They form the spindle apparatus to move chromosomes
What is the key difference between mitosis and meiosis?
Mitosis produces 2 identical cells; meiosis produces 4 unique cells
What is mitosis?
A type of nuclear division that produces two genetically identical diploid daughter nuclei for somatic cells.
List the four stages of mitosis.
- Prophase
- Metaphase
- Anaphase
- Telophase
Prophase?
- Chromatin condenses into chromosomes.
- microtubule organising cnetres (plants)
- centrosomes (animals)
What occurs during metaphase?
Sister chromatids line up on the metaphase plate.
* spindle attaches to cnetromere
* each centromer attached to both poles