Step-by-Step Solution:1. Definition of Pollen Grain: - Pollen grain is a structure that is crucial for the reproduction of flowering plants. It is the male gametophyte that develops from microspores.
It is easily imagined that pollen grains and spores are always exposed to severe drought stress, even though they might have a extraordinarily protective device on their surface coat, as they have an extremely large surface area relative to their volume. As shown in Table I, the ratio of ...
Pollen is vital to our ecosystem but can wreak havoc on asthma, pollen allergies and hay fever. Learn everything you need to know about including pollen count, pollen levels and hay fever tips today!
29 What is a feature of self-pollination? D A It improves the capacity of a species to respond to changes in the environment. B It increases variation in the offspring. C Pollen grains are transferred from the anther of a flower to the stigm a of a flower on a different plant. D P...
Obviously, the fewer allergenic trees in an individual's immediate vicinity, the less the chance of exposure. Good news is that the great majority of wind-borne pollen grains of all species are deposited quite close to their source. The closer to the tree the pollen stays, the less potential...
What is true about pollen? Pollen grains have a dense, solid pollen wall Each pollen grain germinates to form a pollen tube Each pollen grain contains a dozen sperm Pollen grains are formed in the stigmaThere are 3 steps to solve this one. ...
Pollinationis the first required step in sexual reproduction in plants. The male portion of the plant produces the pollen – typically in the flower. A long filament, called a stamen, holds the bits of pollen at the end and one of several pollinators take the pollen grains to the ...
(zoology)Having thesurfacecovered with a fine yellowdust, likepollen. pollinial (palynology)Of or pertaining to apollinium, or large coherent mass of pollen grains. polliniate (botany)Formingpollinia, coherent masses of pollen dispersed as a single unit. ...
which receives the pollen grains and on which the pollen germinates. Without their colorful corolla, flowers do not attract pollinators and are not fertilized. An adult grasshopper can consume a large corolla, about 2.5 inches long, in an hour. Caterpillars and seed beetles affect seed production...
线索词为教授所说:Pollen and starch grains,for example,have been used in archaeological studies,as have what are called “phytoliths.”本篇讲座主要讲解phytoliths(植物岩)在科学研究中的运用。A选项错误,因为花粉与植物岩这两种分析法的对比仅为细节内容。本篇讲座并未全文对比。B选项属原文未提及。文中...