5.fundamental unit of life Flashcards
who discover cells
rrobert hooke
cell theorry was first proposed by
Schleiden and Schwann.
who discovered the nucleus
robert brown
What was the primary contribution of Robert Hooke in the field of cell biology?
He observed and described the first cells in a cork slice.
Which scientist is credited with the discovery of free-living cells in pond water?
Antonie van Leeuwenhoek
The term ‘protoplasm’ was coined by which of the following scientists?
(a) Schleiden
(b) Schwann
(c) Purkinje
(d) Leeuwenhoek
(c) Purkinje
The cell theory states that:
The cell theory states that:
Which of the following organisms is an example of a unicellular organism?
(a) Mushroom
(b) Paramecium
(c) Oak tree
(d) Human
(b) Paramecium
The discovery of which tool in 1940 greatly advanced the study of cell structure?
(a) Light microscope
(b) Optical lens
(c) Scanning electron microscope
(d) Transmission electron microscope
(d) Transmission electron microscope
What is the primary function of the nucleus discovered by Robert Brown?
(a) Energy production
(b) Genetic material storage and regulation of cell activities
(c) Synthesis of proteins
(d) Photosynthesis in plant cells
(b) Genetic material storage and regulation of cell activities
What determines the shape and size of a cell?
(a) The age of the organism
(b) The specific function it performs
(c) The type of nutrients it receives
(d) The presence of organelles
(b) The specific function it performs
Which of the following cells has a changing shape?
(a) Nerve cells
(b) Muscle cells
(c) Amoeba
(d) Red blood cells
(c) Amoeba
What is the primary function of the plasma membrane?
(a) To produce energy
(b) To store genetic material
What is the primary function of the plasma membrane?
(a) To produce energy
(b) To store genetic material
(c) To separate the cell contents from the external environment
(d) To aid in cell division
(d) To aid in cell division
What is the primary function of the plasma membrane?
(a) To produce energy
(b) To store genetic material
(c) To separate the cell contents from the external environment
(d) To aid in cell division
What type of membrane is the plasma membrane classified as?
(a) Permeable membrane
(b) Selectively permeable membrane
(c) Impermeable membrane
(d) Semi-permeable membrane
(b) Selectively permeable membrane
How do substances like oxygen and carbon dioxide move across the plasma membrane?
(a) Active transport
(b) Osmosis
(c) Diffusion
(d) Filtration
(c) Diffusion
What is the movement of water molecules through a selectively permeable membrane called?
(a) Diffusion
(b) Osmosis
(c) Active transport
(d) Facilitated diffusion
(b) Osmosis
When carbon dioxide accumulates in a cell, it moves out of the cell due to which process?
(a) Active transport
(b) Osmosis
(c) Diffusion
(d) Endocytosis
(c) Diffusion
Which of the following components in a cell performs specific functions such as waste removal and material synthesis?
(a) Cell membrane
(b) Organelles
(c) Cytoplasm
(d) Nucleus
(b) Organelles
What is the primary role of the nucleus in a cell?
(a) Energy production
(b) Genetic material storage
(c) Waste removal
(d) Protein synthesis
(b) Genetic material storage
What is osmosis?
The net diffusion of water across a selectively permeable membrane.
What type of solution has a higher water concentration than the cell?
(a) Isotonic solution
(b) Hypertonic solution
(c) Hypotonic solution
(d) Saturated solution
(c) Hypotonic solution
What will happen to an animal cell placed in a hypotonic solution?
(a) The cell will shrink.
(b) The cell will swell up.
(c) The cell will stay the same size.
(d) The cell will burst and die
(b) The cell will swell up.
In an isotonic solution, what happens to the movement of water across the cell membrane?
There is no net movement of water.
What happens to a cell placed in a hypertonic solution?
) The cell will lose water and shrink.
Which of the following describes the movement of water in a hypotonic solution?
More water enters the cell than leaves.
What role does a selectively permeable membrane play in osmosis?
It allows water to pass while controlling the movement of solutes.
When an animal cell is placed in a hypertonic solution, it undergoes a process called:
(a) Cytolysis
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(c) Osmotic pressure
(d) Osmotic balance
(b) Plasmolysis
In a solution with lower solute concentration compared to the cell, water moves:
(a) Out of the cell
(b) Into the cell
(c) In and out equally
(d) Not at all
(b) Into the cell
Which of the following statements is true about osmosis?
(a) It is a form of active transport.
(b) It requires energy input from the cell.
(c) It is a special case of diffusion.
(c) It is a special case of diffusion
What is the main composition of the plant cell wall?
Cellulose.
How do cell walls benefit plant cells in hypotonic environments?
They provide structural support and prevent bursting.
Question: What structure covers the nucleus?
(a) Plasma membrane
(b) Cell wall
(c) Nuclear membrane
(d) Cytoplasm
Nuclear membrane.
Which type of cells lack a nuclear membrane?
Prokaryotic cells.
What is the undefined nuclear region in prokaryotic cells called?
(a) Chromatin
(b) Nucleus
(c) Nucleoid
(d) Nucleolus
(c) Nucleoid
What are chromosomes composed of
DNA and protein.
What phenomenon occurs when a living plant cell loses water through osmosis?
Plasmolysis.
Which type of cells are capable of absorbing water by osmosis?
Only living cells.
What are functional segments of DNA called?
genes
What is one role of the nucleus in a cell?
To direct chemical activities and cellular reproduction