B2.3 Cell Specialisation Flashcards
Requirement for cells regarding the transport of gases and nutrients?
Efficient transport across the membrane to increase surface area-to-volume ratio (SA:V)
This adaptation is crucial for cellular efficiency.
What is a zygote?
An unspecialized cell formed from fertilization
It represents the earliest stage of development in multicellular organisms.
How do chemical gradients influence stem cell differentiation?
They guide gene expression
This process is essential for the development of specialized cell types.
self-renewal in the context of stem cells?
The ability to divide and produce identical stem cells
This property is crucial for maintaining stem cell populations.
Define potency in stem cells.
The capability to differentiate into specialized cell types
Different stem cell types exhibit varying levels of potency.
What are stem cell niches?
Specialized microenvironments supporting stem cell maintenance and regulation
They play a critical role in stem cell biology.
Example of a type of stem cell and its function.
Hematopoietic stem cells generate blood cells
These cells are located in the bone marrow.
What distinguishes totipotent stem cells?
They can differentiate into any cell type, including extra-embryonic tissues
An example is the zygote.
Pluripotent stem cells?
They can form any body cell but not extra-embryonic tissues (no whole organisms)
Embryonic stem cells are a common example.
What are multipotent stem cells capable of?
Differentiating into a limited range of cells
Hematopoietic stem cells are an example of multipotent stem cells.
How does cell size relate to surface area-to-volume ratio (SA:V)?
Smaller cells maintain a higher SA:V
This is important for efficient nutrient uptake and waste removal.
What adaptation do prokaryotic cells exhibit for nutrient access?
They are smaller, maintaining a high surface area-to-volume ratio
This allows for efficient nutrient transport.
How does flattened cell shape benefit squamous epithelial cells?
Facilitates diffusion
These cells are found in areas like alveoli and kidney tubules.
Function of inner membrane invaginations in mitochondria?
Increase metabolic reactions, enhancing ATP production
This adaptation is crucial for energy production.
What structures increase photosynthetic efficiency in chloroplasts?
Thylakoid membranes
These structures increase the reaction sites for photosynthesis.
What role do villi play in the small intestine?
Increase surface area for nutrient absorption
They contain enterocytes with microvilli for maximal absorption.
What adaptation do enterocytes have for nutrient absorption?
Microvilli forming a brush border
This structure increases the absorptive surface area.
What is the function of type I pneumocytes in lung tissue?
Facilitate gas exchange
95% of alveoli
Their thin and flattened structure minimizes diffusion distance.
What is the role of type II pneumocytes?
Produce surfactant to prevent alveolar collapse
Surfactant reduces surface tension and facilitates breathing.
What is a characteristic feature of cardiac muscle cells?
Intercalated discs with gap junctions for synchronized contraction
=> branched for better electrical impulse travel
This structure allows for coordinated heartbeats.
What adaptations do skeletal muscle fibers have?
Long, unbranched fibers and multinucleated syncytia
These features enable controlled movement and high protein synthesis.
What is the primary function of smooth muscle?
Control involuntary movements
Found in blood vessels and the digestive tract.
What are the key features of egg cells?
- Large size
- rich in lipids proteins, and polysaccharides = yolk
- cortical granules = vesicles = enzyme prevent other sperm cell entering
- zona pellucida = glycoprotein protective layer
They have protective layers to prevent polyspermy.
What is the function of the acrosome in sperm cells?
Contains enzymes for penetrating the egg’s zona pellucida
This structure is essential for fertilization.
