Topic 2 Flashcards
(26 cards)
What is cell theory?
A unifying concept that states that cells are a fundamental unit of structure, function, and organisation in all living organisms.
How are cells organised in complex organisms?
Cells are organised into tissues, organs, and organ systems.
What are the key components of prokaryotic cell ultrastructure?
Nucleoid, plasmids, 70S ribosomes, and cell wall.
What is the difference between Gram positive and Gram negative bacterial cell walls?
They react differently to some antibiotics due to structural differences.
What are the main organelles found in eukaryotic cells?
Nucleus, nucleolus, 80S ribosomes, rough and smooth endoplasmic reticulum, mitochondria, centrioles, lysosomes, Golgi apparatus, cell wall, chloroplasts, vacuole, and tonoplast.
What is the importance of magnification and resolution in microscopy?
They can be achieved using light and electron microscopy.
Why is staining specimens important in microscopy?
It enhances visibility and contrast of the specimens.
What is the classification of viruses based on?
Structure and nucleic acid types.
What are examples of viruses based on their nucleic acid type?
λ (lambda) phage (DNA), tobacco mosaic virus, Ebola (RNA), and human immunodeficiency virus (RNA retrovirus).
What is the lytic cycle of a virus?
A process where a virus infects a host cell and replicates, leading to the host cell’s destruction.
Why are viruses not considered living cells?
They cannot replicate independently and require a host.
What is the focus of disease control for viral infections?
Preventing the spread of the virus.
What are the main stages of the cell cycle?
Interphase, mitosis, and cytokinesis.
What happens to genetic material during mitosis?
It is duplicated and equally distributed to two daughter cells.
What is the role of mitosis in organisms?
Contributes to growth, repair, and asexual reproduction.
What does meiosis produce?
Haploid gametes.
How does meiosis contribute to genetic variation?
Through recombination of alleles, including independent assortment and crossing over.
What are chromosome mutations?
Alterations in chromosome structure, such as translocations.
What is non-disjunction and its consequences?
Failure of chromosomes to separate properly, leading to conditions like Down’s syndrome (polysomy) and Turner’s syndrome (monosomy).
What is oogenesis?
The process of egg cell development in females.
What is spermatogenesis?
The process of sperm cell development in males.
What occurs during fertilisation?
The fusion of gamete nuclei after initial contact.
What is the blastocyst stage?
An early stage of embryonic development.
How does a pollen grain form?
It forms in the anther of a flower.
