Tag: biology

Stamens or androecium are the male reproductive part contains filament which is a slender stalk and anther is a bilobed structure which is responsible for the production of pollen grains (male gamete).

Stamens or androecium are the male reproductive part and responsible for the production of pollen grains (male gamete). Pistil or gynoecium are the female reproductive part and produce ovum (female gamete). If both the organs are present it is called bisexual flower. If only one of them is present flower is referred to as unisexual.
So the correct option is 'Presence of stamen and pistil in the flower'.

1. Carpels, pistil or gynoecium are the female reproductive part of the flower that consists of a stigma that holds the pollen grains, the style that leads the path of pollen tube and ovary produce ovum (female gamete). 
   
2. Stamens or androecium are the male reproductive part contains filament which is slender stalk and anther is bilobed and responsible for the production of pollen grains (male gamete). 
   

Non-essential parts of the flowers are the accessory parts that are not directly involved with the gametes formation and sexual reproduction. The whorls of the calyx (individual unit - sepals) and corolla (individual unit - petals) are involved in the protection of flower and attraction of the pollinators, respectively. So, these are considered to be non-essential parts of flowers.

Boiling a leaf in alcohol is a standard procedure in photosynthesis experiments to extract chlorophyll, which allows for the subsequent detection of starch using iodine solution.

The evolutionary sequence of pigments is generally accepted as starting from simpler light-harvesting molecules like carotenoids, followed by chlorophyll, then phycobilins (phycoerythrin/phycocyanin), and finally regulatory pigments like phytochrome.

• Water in the plant is transported using a pressure flow mechanism. Translocation is the transport of nutrients and carbohydrates from source to sink, which is performed by the phloem. Pholem and xylem are present adjacent to each other in the vascular bundle of the plant. When the sugar ie sucrose is produced in the mesophyll of the leaves is produced it is transferred to the phloem to be transported. As the sugar concentration in the phloem increases water is diffused in the phloem from the xylem and this is what we call ascent of sap. When the water is diffused in the cells due the rigid wall the pressure in the cell increases. due to increase in the pressure at the source and low pressure at the sink the water along with the sugar is transported. As the sugar reaches the sink and leaves the cell water also moves out of the cell. Therefore the rate of photosynthesis is dependent on translocation rate. As the rate of translocation decreases the rate of photosynthesis also decreases.
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• Therefore, option A is correct. 
  

Phytochrome is a photoreceptor, a pigment that plants, and some bacteria and fungi, use to detect light. It is sensitive to light in the red and far-red region of the visible spectrum. Many flowering plants use it to regulate the time of flowering based on the length of day and night (photoperiodism) and to set circadian rhythms. It also regulates other responses including the germination of seeds, elongation of seedlings, the size, shape, and number of leaves, the synthesis of chlorophyll, and the straightening of the epicotyl or hypocotyl hook of dicot seedlings. 

Geotropism (also known as gravitropism) is a turning or growth movement by a plant or fungus in response to gravity. It is a general feature of all higher and many lower plants as well as other organisms.