Cell Theory Flashcards
(46 cards)
What makes a living thing?
Reproduction, respiration, response to stimuli, excretion, growth and development, movement, nutrition
Why is the cell cycle important
Growth, repair, reproduction
Growth can refer to an increase in size, complexity, or maturity.
Define ‘Reproduction’ in living organisms.
The ability to reproduce and pass genetic information onto their offspring
Reproduction can be sexual or asexual, contributing to genetic diversity.
What is diffusion
Movement of molecules from a high concentration area to low concentration. Moves nutrients in a cell
This includes reactions to environmental changes such as light, temperature, and sound.
Why can cells not grow big?
- As cells grow larger, the volume grows faster than the membranes’ surface area.
- So eventually either the cell starves to death or is poisoned by toxin build up
- Nutrients take longer to absorb
Movement is a characteristic that can vary widely across different forms of life.
What is interphase
A long non-dividing phase
- cell grows
- general functioning
- G1, S, G2
Nutrition is essential for growth, energy, and maintenance of biological functions.
What are the two main phases in the cell cycle
Interphase and Mitosis
Excretion is crucial for maintaining homeostasis and preventing toxicity.
What is a ‘Cell’?
The smallest unit that can perform all the functions of a living thing
Cells are often referred to as the building blocks of life.
What does Cell Theory state?
- All living things are made up of one or more cells
- The cell is the basic organizational unit of life
- All cells come from preexisting cells
Cell Theory is foundational to understanding biology and the structure of living organisms.
What is mitosis?
A type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus.
What occurs during prophase?
- Chromatin become visible as they condense to form chromosomes (sister chromatids)
- Duplicated centrioles migrate to opposite poles
- Spindle fibers grow from the centrioles
- Nucleolus disappears
- Nuclear membrane breaks down
What happens during metaphase?
- Spindle fibers attach to the centromere
- Chromosomes line up at the middle of the cell, called the equatorial plate
What is the main event in anaphase?
- Spindle fibers shorten
- Sister chromatids separate and move to opposite poles
What are the key events in telophase?
- Cytoplasm splits in half
- Cells return to interphase
- Chromosomes reach poles and unravel back to chromatin
- Spindle fibers break down
- Nuclear membrane forms to make a visible nucleus
- Nucleolus reappears
What is cytokinesis?
Final splitting of cells.
What is the difference in mitosis between plant and animal cells?
Plant cells have a cell wall that forms during cytokinesis, while animal cells undergo cleavage furrow formation.
What characterizes eukaryotic cells?
Contain membrane-bound organelles (e.g. nucleus).
What characterizes prokaryotic cells?
No membrane-bound organelles.
Fill in the blank: In prophase, the _______ is beginning to disappear.
nucleolus
True or False: During metaphase, chromosomes are arranged at the equatorial plate.
True
What are the stages of mitosis?
- Prophase
- Metaphase
- Anaphase
- Telophase
G1 Checkpoint
Transition between G1 and S. Cell commits to mitosis. Checks for: Cell size, growth factors, nutrients, DNA damage
G2 checkpoint
Transition between G2 and Mitosis. Checks for proper DNA replication
Spindle Checkpoint
Transition between Metaphase to Anaphase. Checks that sister chromatids are attached to spindles correctly
