Biology june Flashcards
(61 cards)
What is a cell?
A cell is the smallest unit of life capable of performing all the functions of a living organism.
Why is the cell called the fundamental structural and functional unit of life?
Because it is the smallest unit in nature that exhibits life functions—meaning it can breathe, feed, grow, reproduce, and eliminate waste.
What are the basic parts (organelles) of a cell?
Inside cells, there are distinct compartments called cell organelles. The organelles you should know are: nucleus, plasma membrane, cytoplasm, mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus.
What is the role of the nucleus?
It controls the cell’s functions and contains the organism’s genetic material (DNA). The nucleus is surrounded by a double nuclear membrane.
What is the role of the plasma membrane?
The plasma membrane surrounds the cell and controls what enters and exits. It is made of lipids and proteins.
What is the role of mitochondria?
Mitochondria produce the energy needed for the cell’s functions through a process called cellular respiration.
What is the role of the cytoplasm?
The cytoplasm is the material filling the space between the nucleus and the plasma membrane, serving as the environment in which organelles operate.
What is the role of ribosomes?
They synthesize proteins and are made of proteins and RNA (rRNA).
What are the differences between plant and animal cells?
Plant cells have additional organelles: a cell wall, chloroplasts, and a large vacuole.
What are the functions of the special organelles found only in plant cells?
Chloroplasts: Where photosynthesis takes place. Vacuole: Stores water, salts, and other essential substances. Cell wall: Provides protection and structural support.
What are unicellular and multicellular organisms?
Unicellular: Composed of only one cell (e.g., amoeba, paramecium, euglena). Multicellular: Composed of many cells (e.g., cat, human, olive tree).
What are eukaryotic and prokaryotic organisms?
Eukaryotic organisms: Their genetic material is enclosed within a nuclear membrane (e.g., animals, plants). Prokaryotic organisms: Their genetic material is not enclosed in a nuclear membrane (e.g., bacteria).
What are biotic and abiotic factors in an ecosystem?
An ecosystem consists of biotic factors (living organisms) and abiotic factors (non-living components).
What types of relationships develop among different organisms in an ecosystem?
Feeding relationships, symbiotic relationships, and competitive relationships.
How are organisms classified based on how they obtain their food?
Into autotrophs (producers) and heterotrophs (consumers and decomposers).
What are the categories of consumers?
Primary consumers: Herbivores. Secondary consumers: Carnivores that feed on herbivores. Tertiary consumers: Carnivores that feed on other carnivores.
What is the role of decomposers in maintaining ecosystems?
Decomposers break down dead organic matter into inorganic substances, which can then be reused by producers.
What is a food chain?
A food chain illustrates the feeding relationships among certain populations within an ecosystem.
What is called evolution?
It is the process by which organisms undergo changes in their characteristics as a result of adaptation to their environment.
What is called natural selection?
It is the process by which the best-adapted organisms to their environment survive and reproduce.
Which molecules are responsible for the structural characteristics and functions of organisms?
Proteins.
What does the function of proteins depend on?
On the sequence of their building blocks, which are amino acids.
What determines the sequence of amino acids in proteins?
The sequence of amino acids is determined by the genes in the genetic material.
What are chromosomes?
Chromosomes are the structures in which genetic material is organized, found in the nucleus of eukaryotic cells.
