Biology- part 1 🧬 Flashcards
What is the cell theory
- The cell is the basic unit in which the processes of living things take place
- All living things are made of cells and substances produced by cells
- All cells come from other pre-existing cells
What are unicellular and multicellular organisms?
Unicellular organisms consist of one cell (e.g., bacteria), while multicellular organisms have many specialized cells (e.g., humans).
How do most cells reproduce?
Most cells reproduce by dividing. When dividing each new cell gets a copy of chromosomes and DNA.
Why are cells classified as living things?
All cells are classified as living things- they take in nutrients, eliminate waste products, and grow and reproduce. And in time all cells die.
Name the 12 parts of a cell.
- Cell membrane
- Nucleus
- Vacuole
- Cytoplasm
- Mitochondria
- Ribosomes
- Lysosomes
- Cell wall
- Chloroplast
- Centriole
- Endoplasmic reticulum
- Golgi apparatus
What is the cell membrane and its function?
A cell membrane is a thin flexible semi-permeable cell organelle that regulates the transport of materials entering and exiting the cell. As well as maintaining the cell’s shape.
What is the nucleus and its function?
The nucleus controls the cell’s behavior by storing DNA with instructions for growth and function.
What is the cell membrane and its function?
The cell membrane protects the cell and controls what goes in and out, such as nutrients, waste, and other substances. Therefore, it is semi-permeable.
What is cytoplasm and its function?
The cytoplasm is the jelly-like material inside the cell membrane and outside the nucleus, containing organelles and allowing chemical reactions.
Define protoplasm
The protoplasm includes both the cytoplasm and the nucleus, so it’s essentially all the living material within a cell.
What is chloroplast and its function?
A chloroplast is a green, oval-shaped organelle found in plant cells and it is essential for photosynthesis.
Why don’t unicellular organisms grow as much?
Because they are restricted with a surface area to volume ratio.
Multicellular organisms are ___________, while unicellular organisms are ___________.
a) eukaryotic
b) prokaryotic
Note: All multicellular organisms start as a single cell and as the cell multiplies it starts to specialize in different types of cells.
understood? 🤔
What are the levels of structural organization in the human body?
Cells –> Tissues –> Organs –> Organ systems –> Organism
Note: Being multicellular allows organisms to be larger and ensures that different cell types carry out various tasks. However unicellular organisms can carry out all life processes in just one cell using organelles.
understood? 🤔
What is centriole?
A centriole is an organelle found in animal cells that helps in cell division by organizing spindle fibers to separate chromosomes.
What are lysosomes?
Lysosomes are small sacs filled with enzymes that break down waste, old cell parts, and harmful substances. They act like the cell’s recycling center, enabling the cell to function and stay alive.
What are ribosomes?
Ribosomes are tiny structures in cells that make proteins by reading genetic instructions from RNA. They can be found floating in the cytoplasm or attached to the endoplasmic reticulum.
What are mitochondria?
Mitochondria produce energy by breaking down food molecules. This energy, stored as ATP, powers the cell’s activities.
What are vacuoles?
Vacuoles are storage sacs in cells that hold water, nutrients, or waste. They are larger in plant cells, helping maintain shape and pressure, and smaller in animal cells, mainly for storage and transport.
What is a cell wall?
A cell wall is a rigid outer layer found in plant cells. It provides structural support, and protection, and helps maintain the cell’s shape. In plants, it’s made of cellulose.
What is the endoplasmic reticulum?
The endoplasmic reticulum (ER) is a network of interconnected layers inside the cell that helps produce, process and transport proteins and lipids. There are two types: the rough ER, which has ribosomes on its surface and helps make proteins, and the smooth ER, which makes lipids and removes harmful substances.
What is the Golgi apparatus?
The Golgi apparatus is a cell organelle that modifies, sorts, and packages proteins and lipids for transport to different parts of the cell or outside the cell.
What is osmosis?
It involves the movement of molecules from a region of higher concentration to a region of lower concentration until the concentrations become equal on either side of the membrane.
When someone gets an IV it may look like the fluid in the tube is water but it is not. Why?
Because let’s say hypothetically pure water was in an IV. An IV tube typically runs through your vein so that doctors can access your bloodstream. Because red blood cells have a higher solute concentration, water from the IV will travel to the red blood cells causing it to burst.
What is solute and solvent?
The solute is the substance being dissolved, while the solvent is the dissolving medium.
What is hypotonic?
Lower solute concentration (when compared to another substance)
What is hypertonic?
Higher solute concentration (when compared to another substance).
What are the levels of structural organization in the human body?
Cells –> Tissues –> Organs –> Organ systems –> Organism
Why can’t unicellular organisms grow larger?
1) surface area to volume ratio
2) hinder their ability to divide efficiently
3) they don’t need to grow large they can store all of their materials from the vacuole.
What is the relationship between prokaryotic cells, eukaryotic cells, unicellular organisms, and multicellular organisms?
prokaryotic cells –> always unicellular
eukaryotic cells –> either unicellular or multicellular
unicellular organisms –> either prokaryotic or eukaryotic
multicellular orgnaims –> multicellular
