2A1 Ultrastructure Of Cells & Living Characteristics Flashcards
Gain understanding of diverse cellular structures in living organisms.
What is the basic unit of life that determines the activities of an organism?
A cell.
What are animal cells characterized by?
- Contain a nucleus.
- Contain membrane-bound organelles (e.g. mitochondria).
Animal cells are eukaryotic cells.
What is the function of the nucleus in cells?
It controls most cell activities, including metabolism, growth, and reproduction, and contains DNA.
Which organelle is present in both plant and animal cells and is responsible for the release of energy from glucose?
Mitochondria
Mitochondria are often referred to as the powerhouses of the cell because they generate most of the cell’s supply of adenosine triphosphate (ATP), used as a source of chemical energy.
What is the function of ribosomes in a cell?
Help synthesize proteins.
Ribosomes can be found floating freely within the cytoplasm or attached to the endoplasmic reticulum, forming the rough ER.
What fills the inside of a cell and covers the organelles?
Cytoplasm
It’s a jelly-like fluid.
Which part of the animal cell in the diagram controls what substances enter and leave the cell?
Plasma membrane
The plasma membrane is the outer boundary of a cell that separates it from the external environment.
Describe the structure of mitochondria.
- Oblong organelles.
- Have a highly-folded inner and an outer membrane.
- A gel-like material called the matrix.
The inner membrane in mitochondria folds to form a structure called the ‘cristae,’ while the outer membrane is even and porous. Mitochondria are responsible for releasing energy in the cell.
Describe the structure of the golgi apparatus.
- A membrane-bound organelle.
- Comprises a series of stacked, flattened discs called cisternae.
The Golgi apparatus helps package and secrete proteins in the cell.
What is the function of the Golgi body?
- Processes and modifies proteins received from the endoplasmic reticulum (ER).
- Packages proteins into vesicles.
What are organelles and what is their significance in plant & animal cells.
Structures that perform specific jobs, helping maintain cellular balance and keeping the cell alive.
What do lysosomes do in an animal cell?
They contain hydrolytic digestive enzymes that break down and recycle toxic substances and waste.
Why do animal cells lack a cell wall?
They do not require the rigidity and support that cell walls provide to plant cells.
How does the nucleus contribute to genetic information transfer?
It contains DNA and forms chromosomes that pass genetic information from parents to offspring.
Differentiate between rough ER and smooth ER.
- Rough ER: has ribosomes and aids in protein synthesis.
- Smooth ER: lacks ribosomes and helps in lipid synthesis and detoxification.
Ribosomes can be scattered within the cell or attached to the ER. Rough ER contains ribosomes, while smooth ER does not.
How do mitochondria differ in various cell types?
Heart & muscle cells have more mitochondria due to their constant need for energy, compared to cells like skin or bone cells.
What is binary fission?
A method of asexual reproduction in cells.
Binary fission is most commonly seen in prokaryotic organisms like bacteria, where a single cell divides into two identical daughter cells.
Example: bacteria reproduce by binary fission.
What is the difference between prokaryotic and eukaryotic cells?
- Prokaryotic cells do not have a nucleus.
- Eukaryotic cells have a nucleus.
The diagram shows a plant cell.
Which organelle stores water, nutrients, and waste products?
The central vacuole.
The fluid inside the plant cell vacuole is called ‘cell sap’.
In which part of the plant cell diagram does photosynthesis take place?
The chloroplast.
