Test: Cell: The Unit of Life - 2 - NEET MCQ

Animal cell do not possess plasmodesmata but it contain ribosomes, centriole andplamalemma. Plasmodesmata is the connection between two plant cells.

The lipid molecules of plasma membrane occurs parallel to each other in plasma membrane of the cell.

In plant cells the vacuoles can occupy up to 90 per cent of the volume of the cell.

Mitochondria and chloroplast contain theirown genetic material. Genetic material is mainly present in nucleus of the cell but these two cell organelles also contain own genetic material.

The ability of a living somatic nucleated cell to form the complete organism is called cellular totipotancy. Cellular totipotancy is present in plant cells.

The plasma membrane is composed of lipids that are arranged in a bilayer. Also, the lipids are arranged within the membrane with the polar head towards the outer sides and the hydrophobic tails towards the inner part. The membrane proteins can be classified as integral or peripheral. Peripheral proteins lie on the surface

The chloroplast consists of a number of organised flattened membranous sacs called the thylakoids,Chlorophyll pigments are present in the thylakoids.

The stacks or closely packed thylakoids is called granum. Chlorophyll is present inside the thylakoidsto perform photosynthesis in plant cells.

Nerve cell or neuron is the longest cell in human body. They are responsible for transferof information from one part of the body to the other in form of nerve impulses.

Fluid-Mosaic model is the most recent and accepted model of plasma membrane. This model was proposed by Singer and Nicolson in 1972. The quasi-fluid nature of lipid enables lateral movement of proteinswhithin the overall bilayer.

Nucleus as a cell organelle was first described by Robert Brown as early as 1831.

The cell wall of a young plant cell, the primary wallis capable of growth, which gradually diminishes as the cell matures and the secondary wall is formed on the inner (towards membrane) side of the cell.

Most prokaryotic cells, particularly the bacterial cells, have a chemically complex cell envelope. All eukaryotic cells are not identical. Plant and animal cells are different as the former possess cell walls.

PleuroPneumonia Like Organisms (PPLOs) are considered as smallest free living organism. It do not contain cell membrane or cell wall and present as fluid. It causes disease in plants.

All animal cell have two small organelles called centrioles. Each centriole is surrounded by dense amorphous protoplasmic masses called Massules.

These are membrane bound vesicular structures formed by the process of packaging in the Golgi apparatus.

An elaborate network of filamentous proteinaceous structures present inthe cytoplasm is collectively referred to as the cytoskeleton.

An improved model of the structure of cell membrane was proposed by Singer and Nicolson (1972) widely accepted as fluidmosaic mosaic model.

Tonoplasts are the fluid filled vacuoles or vesicles which are separatedfrom cytoplasm by a selectively permeable membrane. It help in maintaining turgidity of the cell.

Ideogram is a photograph or diagram of metaphases chromosomes of an organism arranged in homologous pair according to their length, thickness and position of centromere, length of arm, shape and other characteristics. The sex chromosomes are usually placed at the end.

The eukaryotic ribosomes are 80S while the prokaryotic ribosomes are 70S. Here ‘S’ stands for the sedimentation coefficient; it indirectly is a measure of density and size.

Active transport is the movement of molecules or ions against a concentration gradient (from an area of lower to higher concentration), which does not ordinarily occur, so enzymes and energy are required.

The number of proteins synthesised by ribosomes on the endoplasmic reticulum are modified in the cisternae of the golgiapparatus .

The inner membrane forms a number of infoldings called the cristae
They produce cellular energy in the form of ATP, hence they are called ‘power houses’ of the cell. The matrix also possesses single circular DNA molecule, a few RNA molecules, ribosomes (70S) and the components required for the synthesis of proteins. The mitochondria divide by fission.

9 + 2 arrangement of the axonemal microtubules of cilia/flagella