Pigments involved in Photosynthesis

What is PAR range?

Assertion : Cyclic pathway of photosynthesis first appeared in some eubacterial species.

Reason : Oxygen started accumulating in the atmosphere after the non-cyclic pathway of photosynthesis evolved.

What is chlorophyll?

A student working in a lab had three tubes with the following preparations:

(i) Freshly extracted nucleic acids dissolved in a buffer.

(ii) Chlorophyll extracted from spinach leaf.

(iii) Red coloured anthocyanin from onion cells.

The student used a spectrophotometer to determine the wavelength of light at which each preparation would show maximum absorption (absorption spectrum). She noted down the values in her notebook. However, when she came to the lab the next day, she realised that she had not mentioned the name of the sample preparation against each value. The values she recorded were 480 nm, 260 nm, and 642 nm. The respective values for the sample (i), (ii), and (iii) would most likely be:

Assertion: The absorption spectrum of chlorophyll - '$\mathrm{a}$' shows one-to-one overlap with the action spectrum of photosynthesis.

Reason: Higher rate of photosynthesis occurs at the blue and red wavelengths corresponding to the absorption spectrum of chlorophyll - '$\mathrm{a}$'.

The correct option among the following is:

Which chlorophyll is more efficient?

Mention the names of important accessory pigments present in plants. 

Name the two types of photosynthetic pigments.

If chlorophyll is burnt, then which of the following is left in ash?

Name any three photosynthetic pigments.

If a pure chlorophyll solution is illuminated with ultraviolet light, the solution appears:

Assertion: There is a decrease in photosynthesis, if the photosynthetic cells are illuminated by light of ${\mathrm{P}}_{680 }\mathrm{nm}$ or more wavelength.

Reason: In red drop phenomenon the rate of photosynthesis decreases.

Three of the graphs below show the absorption spectra of photosynthetic pigments. One graph shows the action spectrum of photosynthesis for a plant containing the pigments.

All the $\mathrm{x}$ axis show wavelength. Three of the $\mathrm{y}$ axis show light absorption. One $\mathrm{y}$ axis shows the rate of photosynthesis

Photosynthesis takes place:

Identify A and B in the following diagram.

Following is the absorption spectrum of photosynthesis. Determine $\mathrm{X}, \mathrm{Y},$ and $\mathrm{Z}.$

Which of the following is least effective in photosynthesis?

_______ is considered to be the most effective wavelength of light for photosynthesis.
 

Most light absorption occurs in the region (PAR) of?

The reaction centre of PS-II is_____.