Different structures and functions of roots
Explanation:
Roots are the underground descending non-green part of the plant.
Root functions: Anchorages the plant to the soil, absorbs water and nutrients from the soil.
Characteristics: Positively geotropic and hydrotropic, negatively phototropic; does not have nodes, internodes or stems.
Types:
- Tap root
- Adventitious root – fibrous, foliar and true adventitious roots
Structure and functions:
- Root cap or Calyptra: Cap-like structure covering the root tip
.
- Function: protects the meristematic tissues of the root, secretes mucilage which enhances the root tips to grow into the hard soil.
- Meristematic zone or growing point sub-terminal behind root cap. These cells are inverted and looks like a dome.
- Function – helps in the root growth by adding new cells to the root tip and other basal regions
- Zone of elongation behind the meristematic zone.
- Function – helps in elongation of the root
- Root hair zone: This is the zone of differentiation where cells differentiate into vascular tissues like phloem, xylem, endodermis, cortex etc.
- The main function of root hair is to increase the total surface area of root to facilitate more absorption of water and other nutrients from the soil
- Zone of maturation: the major and mature portion of a root.
- Function - lateral roots originates from this zone and radial differentiation leads to secondary growth.
Answer:
I think true statement is A.
Answer:
D. Psychrophile
Explanation:
Psychrophiles or cryophiles are a type of extremophiles i.e. they live in extreme environment. They grow well in low temperatures ranging from -20 to +10 degree Celsius.
Here, the bacteria was incubated at different temperatures. It did not show growth at standard incubation temperature of 37°C which indicates that it might be an extremophile preferring either very hot or very cold environment. But it also did not show growth at 50°C which means that it does not survive well at high temperature.
Lab bench top has generally colder surface compared to the surrounding environment and a little growth was observed there which indicates that this bacteria might require cold temperature for growth. The result was finally confirmed with abundant growth observed inside refrigerator which is only possible if it is a psychrophile.
Course alteration is the first to be utilized to find the example, and just with the low power objective. When seeing an example, you should dependably utilize the lower control target focal points first. Low power focal point gives the most stretched out field of view and makes it less demanding to discover the example when you look through the magnifying lens. Finding the example at high power, without first focusing it in the field of view at low power, is almost outlandish.
Exponential growth, because of the shape of the curve.
