Untitled Deck Flashcards
(35 cards)
Why do cells divide?
Cells divide to stay small, efficiently exchange nutrients, replace damaged cells, and reproduce.
What happens to surface area and volume as a cell grows?
As a cell grows, its volume increases faster than its surface area, making it harder to exchange materials.
What is sexual reproduction?
Involves two parents, produces genetically diverse offspring, but is slower.
What is asexual reproduction?
Involves one parent, fast and efficient, but produces identical offspring with no genetic variation.
What are chromosomes?
Structures made of DNA that carry genetic information and ensure accurate division during cell replication.
How do eukaryotic and prokaryotic cells divide?
Eukaryotic cells divide by mitosis, involving multiple steps. Prokaryotic cells divide by binary fission, a simpler process.
What is chromatin?
Uncoiled, loose DNA found in the nucleus when the cell is not dividing.
What is a histone?
A protein that helps DNA coil into chromatin for packaging inside the nucleus.
What is a chromatid?
One of two identical halves of a duplicated chromosome.
What is a chromosome?
A tightly packed structure of DNA and proteins, essential for cell division.
What is a centromere?
The central region of a chromosome that holds sister chromatids together.
What is a centriole?
Organelle in animal cells that helps organize spindle fibers during cell division.
What is the cell cycle?
The process of cell growth and division, including G1 (growth), S (DNA replication), G2 (preparation), and M (mitosis).
What is mitosis?
The division of a cell’s nucleus into two identical daughter nuclei.
What is cytokinesis?
The division of the cytoplasm, completing the formation of two new cells.
What happens during prophase?
Chromosomes condense, the nuclear membrane dissolves, and spindle fibers form.
What happens during metaphase?
Chromosomes line up at the center of the cell, attached to spindle fibers.
What happens during anaphase?
Sister chromatids separate and move toward opposite ends of the cell.
What happens during telophase?
Two new nuclear envelopes form around separated chromosomes, which de-condense.
How do plant and animal cells divide differently?
Plants form a cell plate to divide. Animals form a cleavage furrow to split the cytoplasm.
What are internal regulators?
Proteins inside the cell that ensure processes happen in the right order (e.g., checking DNA replication).
What are external regulators?
Signals from outside the cell, like growth factors, that control when a cell divides.
What is cyclin?
A protein that controls the timing of the cell cycle.
What is a tumor?
A mass of cells growing uncontrollably due to cell cycle failure.
