Select the correct statement from the following regarding cell membrane:
1. | Na+ and K+ ions move across cell membranes by passive transport |
2. | Proteins make up 60% to 70% of the cell membrane |
3. | Lipids are arranged in a bilayer with polar heads towards the inner part |
4. | Fluid mosaic model of the cell membrane was proposed by Singer and Nicolson |
Which one of the following structures between two adjacent cells is an effective transport pathway?
1. Plasmodesmata
2. Plastoquinones
3. Endoplasmic reticulum
4. Plasmalemma
1. Golgi apparatus
2. plastid
3. lysosome
4. vacuole
Which one of the following has its own DNA?
1. Mitochondria
2. Dictyosome
3. Lysosome
4. Peroxisome
The main arena of various types of activities of a cell is:
1. Plasma membrane
2. Mitochondria
3. Cytoplasm
4. Nucleus
The plasma membrane consists mainly of:
1. phospholipids embedded in a protein bilayer
2. proteins embedded in a phospholipid bilayer
3. proteins embedded in a polymer of glucose molecules
4. proteins embedded in a carbohydrate bilayer
Alage have cell wall made up of:
1. Cellulose, galactans and mannans
2. Hemicellulose, pectins and proteins
3. Pectins, cellulose and proteins
4. Cellulose, hemicellulose and pectins
Middle lamella is mainly composed of:
1. hemicellulose
2. muramic acid
3. calcium pectate
4. phosphoglycerides
Plasmodesmata are:
1. | lignified cemented layers between cells |
2. | locomotory structures |
3. | membranes connecting the nucleus with plasmalemma |
4. | connections between adjacent cells |