Yellow-fruit nightshade

This plant is called yellow-fruit nightshade or कन्टकरी. Its botanical name is Solanum virginianum. This thorny herb grows in wild, on roadside and near farms. 

It bears beautiful, purple flowers and brinjal-like fruit. 

It is considered to be a poisonous plant. However, it has several medicinal uses also.

Factors Affecting Photosynthesis

According to Blackman's law of limiting factors, if a chemical process is affected by more than one factor, then the rate of reaction will be determined by the factor which is nearest to its minimal value.

Photosynthesis is affected by factors like light intensity, carbon dioxide concentration, temperature and water. 

1. Light: if light increases, photosynthesis also increases upto a certain level. Then it remains constant. Plants need only 10% of the available light intensity of sunlight. Therefore, light is never a limiting factor except in case the plant is in shade or in dense forest. 

If the light intensity increases too much, it starts destroying the chlorophyll, thus, photosynthesis reduces. 

2. Carbon dioxide: if amount of carbon dioxide increases, photosynthesis also increases upto CO2 concentration of 0.05 %. Then photosynthesis reduces. 

Saturation level or optimum level of carbon dioxide for C4 plants is 360 microlitre per litre of air; and for C3 plants is 450 microlitre per litre of air. Thus, carbon dioxide is a limiting factor more for C3 plants. 

3. Temperature: if temperature increases, photosynthesis also increases upto a certain level. Then photosynthesis reduces. C3 plants have lower optimum temperature (18 to 24 degree celsius). C4 plants have a little higher optimum temperature (30 to 40 degree celsius). 

4. Water: if available water is more, photosynthesis increases up to a certain level. Then there is no effect. If water available is less, the stomata do not open fully. So absorption of carbon dioxide is less. Thus, photosynthesis will also be less. 

Camels of Rajasthan (India)

These are the camels of Rajasthan. The zoological name of camel is Camelus dromedarius. These are very large, strong and handsome creatures. They are reared mainly for milk and to carry load. Once they were abundant in this area but now they are in crisis. Their number is decreasing and they now need support. 

Squirrel

This is a northern palm squirrel (Funambulus pennantii). It has five black-brown stripes on its back. It lives on trees. It is quite active and playful creature. Children like to observe it sitting, playing or searching for food. It doesn't sit in one place; though in summer, it likes taking rest on wet ground in the shade of a tree. 

Krebs' Cycle

Pyruvic acid which is produced in glycolysis is transported into the mitochondria where it is converted into acetyl CoA. Then, CoA enters the Krebs' cycle that takes place in the matrix of the mitochondria. 

NADH2 and FADH2 are generated in the Krebs' cycle. 

Glycolysis

In cellular respiration, oxidation of glucose takes place. The initial stage of cellular respiration takes place in the cytoplasm. Glucose molecule is broken down through a series of enzyme-catalyzed reactions into two molecules of pyruvic acid. This process is known as glycolysis.

Note: The above notes in the image(s) are taken from a personal notebook which was initially not intended to be shared online. Please excuse the rough handwriting and the spelling errors, if any. 

Morpankhi plant

This is an oriental thuja (मोरपंखी) plant (Platycladus orientalis also called Thuja orientalis). 

It is a gymnosperm and belongs to cypress family. It is used as ornamental plant or as hedges in gardens. 

Canna flower

This is a flower of canna plant, also called canna lily (Canna sp) . 

The flowers may be yellow, orange, red etc or in a combination of these colours.

It is a monocot plant and looks slightly like a banana plant. 

It has contractile roots. 

Its rhizome is rich in starch. 

CAM Cycle and Photorespiration

Crassulacean Acid Metabolic Cycle or CAM cycle is found in in plants of crassulaceae family eg Kalanchoe pinnate (bryophyllum) and euphorbiaceae family eg Euphorbia sp, codiaeum variegatum etc. 

Photorespiration:

Photo respiration occurs in C3 plants. In C3 cycle, rubisco enzyme binds with carbon dioxide and and through the cycle it produces glucose. Some of the rubisco enzyme also binds with oxygen, if the amount of oxygen is high and temperature is high. Thus, the amount of glucose produced is less. Moreover, some of the glucose produced is also oxidized which causes further loss of glucose. This is called photo respiration because it is not the main respiration which takes place in mitochondria but another type of respiration which takes place in the presence of sunlight. 

C4 Cycle

Some tropical plants like maize, sugarcane, many grasses, sorgam, millet, many plants of asteraceae, many plants of brassicaceae etc show a special type of photosynthesis called C4 cycle or C4 pathway. In this type of pathway, the first product of carbon dioxide fixation (malic acid or aspartic acid) is formed in the cells of mesophyll. It is a 4 carbon compound. 

Malic acid is transferred to the bundle sheath cells where it is converted into pyruvic acid. Pyruvic acid then takes part in the C3 cycle or Calvin cycle.

Class 11 Photosynthesis

In the mesophyll cells of the leaves, there are a large number of chloroplasts. The membranes of granna inside chloroplast are the site for the light reaction while the dark reaction takes place in the matrix of the chloroplast ie stroma. 

In the light reaction, the light energy is absorbed by the pigment present in the antenna and funneled to special chlorophyll a molecules called Reaction Centre chlorophylls. 

There are two photo systems, PS1 and PS2. PS1 has a 700 NM absorbing chlorophyll called Chlorophyll a P700 molecule at its reaction centre, while PS2 has a P680 reaction centre that absorbs red light at 680 NM. After absorbing light, electrons are excited and transferred through PS2 and PS1 and finally to NAD forming NADH. 

Initially, in the dark reaction, carbon dioxide is added by the enzyme RuBisCO to a 5 carbon compound RuBP that is converted to two molecules of 3 carbon PGA. This is then converted to glucose. In this process, ATP and NADPH synthesized in the light reaction are utilised. 

Note: The above notes in the image(s) are taken from a personal notebook which was initially not intended to be shared online. Please excuse the rough handwriting and spelling errors, if any. 

Plant Life Cycle and Metagenesis

In the life cycle of sexually reproducing plants, there is alternation of generations (metagenesis) between gamete-producing haploid gametophyte and spore-producing diploid sporophyte.

However, different plant groups as well as individual plants may show different patterns of life cycles. 20 life cycles are haplontic, diplontic or haplo-diontic (intermediate).

Note: The above notes in the image(s) are taken from a personal notebook which was initially not intended to be shared online. Please excuse the rough handwriting and the spelling errors, if any. 

Class 11 Gymnosperm

The gymnosperms have ovules which are not enclosed by any ovary wall. The seeds remain exposed after fertilization and so these plants are called naked-seeded plants. The gymnosperms produce microspores and megaspores in microsporangia and megasporangia respectively. Microsporangia are borne on microsporophylls while megasporangia are borne on megasporophyll. These sporophylls are arranged spirally on axis to form male and female cones. The pollen grain germinates and pollen tube releases the male gamete into the ovule, where it fuses with the egg cell in archigonia. After fertilization, the zygote develops into embryo and the ovules into seeds. 

Note: The above notes in the image(s) are taken from a personal notebook which was initially not intended to be shared online. Please excuse the rough handwriting and spelling errors, if any. 

An Important Observation on Periwinkle Flowers

Dear readers,

This article discusses an important observation in my garden.

____________________________________

This is a Periwinkle plant ( Catharanthus roseus, formerly known as Vinca rosea) with dark pink flowers with white centre.

Only one sapling was brought to the garden a few months ago. There was no other periwinkle near by. Later, the plants spread in the garden and gave flowers of different colours. 

Like, 

1. Light pink flower with dark pink centre

2. Light pink flower with white centre

3. White flower with white centre

4. White flower with light pink centre

In this way, we got periwinkle plants with five kinds of flowers.

Garden Lizard 🦎

This is an Oriental garden lizard (Calotes versicolor), an insect-eating reptile. 

Note its ability to camouflage with the surroundings.

Also note that the lizard in both the pictures is one and the same.

Class 11 Kingdom Protista

All unicellular eukaryotes are placed under Kingdom Protista. They include chrysophytes, dinoflagellates, euglenoids, slime moulds and protozoans. They are primarily aquatic. The cell body contains a well defined nucleus and other membrane-bound organelles. Some have flagella or cilia. They reproduce asexually and sexually by a process involving cell fusion and zygote formation. 

Note: The above notes in the images are taken from a personal notebook which was initially not intended to be shared online. Please excuse the rough handwriting and spelling errors, if any. 

Class 11 Kingdom Fungi

Fungi are eukaryotic, heterotrophic organisms with cell wall of chitin. They are mostly multicellular and filamentous (exception: yeast is unicellular and non-filamentous). Their body consists of long, slender thread-like structure is called hyphae. The network of hyphae is known as mycelium. Hyphae may be septate or coenocytic based on the presence or absence of septae or cross wall in the hyphae.

Fungi are mostly saprophytes , some are parasites; and few are symbionts. 

Phycomycetes, Ascomycetes, Basidiomycetes  and deuteromycetes are the four classes under this Kingdom. 

Note: The above notes in the images are taken from a personal notebook which was initially not intended to be shared online. Please excuse the rough handwriting and spelling errors, if any. 

Purple Sunbird

This is a purple sunbird (Cinnyris asiaticus also called Nectarinia asiaticus ) collecting nectar from drumstick tree flowers. It is in its non-breeding season. It is a female bird; the male one has a black patch on the chest. In their breeding season the males change the colour of their feathers to shining purple-black. 

Drumstick tree flowers

These are the beautiful white flowers of drumstick tree (Moringa oleifera).

You can also see a honeybee (Apis sp) in this video collecting nectar from the flower.

Pods of drumstick tree and it leaves are very nutritious. They have several vitamins, minerals and protein. Several people use their flowers to make vegetable curry. 

Yellow flowers

These are the flowers of yellow trumpet plant / Yellow Elder (Tecoma stans). 

Inflorescence is racemose. 

The plant has got plenty of flowers; and it really looks beautiful. 

A Spider🕷️, Black, Brown in Colour

This is is another spider which I found the other day (31 October 2020). It was sitting on the inner wall of a water tank. It has camouflaged itself with the wall. 

If you know the name of this species please comment. 

A Spider🕷️, Green in Colour

This is the spider I saw a few days ago (30 Oct 2020). I saw this spider hanging from its web which it had made on the rear mirror of my car. 

I don't know what species it is. If you have any idea please let me know in the comment section. Meanwhile, I'll try to to get some information on the internet.

On the internet: 

One of the website says that it is Araneus mitificus (Kidney Garden Spider). I found that this spider is reported from several places of India, Bangladesh, Malaysia etc.

First post

Hello, readers!

Recently I saw an interesting spider. And I thought that I should start a blog to share the pictures of some animals and plants.

So this is that blog in front of you. I'll soon share the picture of the spider with you. And some more interesting pictures of plants and animals in future. 

And I'll discuss on some important topics of Biology of Class 11 and 12 NCERT. I'll also share a few Worksheets for Self Assessment/Practice Test. 

I hope this blog will be useful to students, teachers and all others. That's why I call this blog Biology for People and Biology for All.