The two subunits of ribosomes remain united at a critical ion level of
1. Magnesium
2. Calcium
3. Copper
4. Manganese

Polysome is formed by
1. A ribosome with several subunits
2. Ribosomes attached to each other in a linear arrangement
3. Several ribosomes attached to a single mRNA
4. Many ribosomes attached to a strand of endoplasmic reticulum

Vacuole in a plant cell
1. Lacks membrane and contains air.
2. Lacks membrane and contains water and excretory substances.
3. Is membrane bound and contains storage proteins and lipids.
4. Is membrane bound and contains water and excretory substances.

In germinating seeds, fatty acids are degraded exclusively in the
1. Peroxisomes
2. Glyoxysomes
3. Mitochondria
4. Proplastids

Keeping in view the fluid mosaic model for the structure of cell membrane, which one of the following statement is correct with respect to movements of lipids and proteins from one lipid monolayer to the other (described as flip flop movement) ?

1. While proteins can flip-flop, lipids cannot
2. Neither lipids nor proteins can flip-flop
3. Both lipids and proteins can flip-flop
4. While lipids can rarely flip-flop, proteins cannot

Genes present in the cytoplasm of eukaryotic cells are found in
1. Lysosomes and peroxisomes
2. Mitochondria and inherited via egg cytoplasm
3. Golgi bodies and smooth endoplasmic reticulum
4. Plastids and inherited via male gamete.

Plasmodesmata are
1. Connections between adjacent plant cells
2. Lignified cemented layers between cells
3. Locomotory structures
4. Membranes connecting the nucleus with plasmalemma

Stroma in the chloroplasts of higher plant contains
1. ChlorophyII
2. Light-independent reaction enzymes
3. Light-dependent reaction enzymes
4. Ribosomes

Middle lamella is composed mainly of

The plasma membrane consists mainly of
1. Proteins embedded in a phospholipid bilayer
2. Proteins embedded in a polymer of glucose molecules
3. Proteins embedded in a carbohydrate bilayer
4. Phospholipids embedded in a protein bilayer