What are the components of the transport system in highly organised plants?
Transportation in plants:- There are two components for the transportation in highly organised plants. Transportation of some materials like gases, water, minerals, organic solutes in the form of food, hormones occurs by these two components- xylem and phloem.
Xylem:- transportation of water and minerals occurs through the xylem. Water and minerals are absorbs from the soil and then by the roots, transport it to the tip of growing stem in the sequential manner. This uptake of water and minerals followed by some processes like osmosis, diffusion. Water and minerals are transported through the root hair to the cortex and then to the leaves by the two pathway apoplast and symplast by the root pressure and the transpirational pull activity. This process is unidirectional.
Phloem:- Phloem helps in transportation of food in the form of organic solutes from leaves to the storage organs of the plant and to all parts of the plants, this process is known as translocation. Food is transported through the sieve elements of the phloem and needs metabolic energy to transport the food. They use this metabolic energy in the form of ATP and by the process of osmosis water enters in the sieve tubes that raise the pressure in the phloem and then the food is transported to the parts of the plants. Transportation of food movement involves along the turgor pressure gradient that is induced by maintained gradient of water potential. This process is multidirectional.
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
Outline a project which aims to find the dominant coat colour in dogs.
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?
How is the sex of the child determined in human beings?
(a) What property do all elements in the same column of the Periodic Table as boron have in common?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common?
Calculate the number of electrons constituting one coulomb of charge.
What is an homologous series? Explain with an example.
Why is variation beneficial to the species but not necessarily for the individual?
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?
Why is the conversion of ethanol to ethanoic acid an oxidation reaction?
Oil and fat containing food items are flushed with nitrogen. Why?
How can three resistors of resistances 2 Ω, 3 Ω, and 6 Ω be connected to give a total resistance of (a) 4 Ω, (b) 1 Ω?
What are amphoteric oxides? Give two examples of amphoteric oxides.
We saw in this chapter that there are four main stakeholders when it comes to forests and wildlife. Which among these should have the authority to decide the management of forest produce? Why do you think so?
Why do we prefer a convex mirror as a rear-view mirror in vehicles?
Name two energy sources that you would consider to be renewable. Give reasons for your choices.
Let the resistance of an electrical component remains constant while the potential difference across the two ends of the component decreases to half of its former value. What change will occur in the current through it?
Which of the statements about the reaction below are incorrect?
2PbO(s) + C(s) → 2Pb(s) + CO2(g)
(a) Lead is getting reduced.
(b) Carbon dioxide is getting oxidised.
(c) Carbon is getting oxidised.
(d) Lead oxide is getting reduced.
(i) (a) and (b)
(ii) (a) and (c)
(iii) (a), (b) and c
(iv) all