1.1 Introduction to Cells Flashcards
what does the evolution of multicellular organisms allow?
cell specialization and replacement
what is the cell theory?
1: all living things are composed of cells
2: the cell is the smallest unit of life
3: cells only arise from pre-existing cells
what examples can be used to question the cell theory
striated muscle, giant algae, aseptate hyphae
why are striated muscles an exception to the cell theory?
muscle cells fuse to form very long fibres so they have multiple nuclei which challenges the idea that cells always function as autonomous units
why is giant algae an exception to the cell theory?
certain species may grow to large sizes which challenges the idea that larger organisms are made of microscopic cells
why is aseptate hyphae an exception to the cell theory?
some fungi are not partitioned and so they have a continuous cytoplasm along the length of the hyphae
what are the basic functions of life integral to survival?
Metabolism, reproduction, homeostasis, growth, sensitivity, excretion, nutrition
how unicellular organisms fulfil the 7 basic functions differs depending on their…
structure and habitat
is Paramecium a heterotroph or an autotroph?
heterotroph
what feature of paramecium allows for responsiveness?
small hairs called cilia which allow it to move
what feature of paramecium allows for nutrition?
specialized membranous feeding groove
what feature of paramecium allows for metabolism?
small vacuoles that contain digestive enzymes
what feature of paramecium allows for excretion?
anal pore for food and contractile vacuoles for liquids
what feature of paramecium allows for homeostasis?
essential gasses enter and exit via diffusion
what feature of paramecium allows for reproduction?
fission
