PACE WORK 9th FORM

Дата: 18.03.2020

Тема:Вищі спорові рослини

Зміст уроку: загальна характеристика вищих спорових рослин. Будова і процеси життєдіяльності. Робота з текстом. Лексичні вправи

1. Read the text and make up a plan for it

Spore, a reproductive cell capable of developing into a new individual without fusion with another reproductive cell. Spores thus differ from gametes, which are reproductive cells that must fuse in pairs in order to give rise to a new individual. Spores are agents of asexual reproduction, whereas gametes are agents of sexual reproduction. Spores are produced by bacteria, fungi, algae, and plants.

Bacterial spores serve largely as a resting, or dormant, stage in the bacterial life cycle, helping to preserve the bacterium through periods of unfavourable conditions. Spore production is particularly common among Bacillus and Clostridium bacteria, several species of which are disease-causing. Many bacterial spores are highly durable and can germinate even after years of dormancy.

Among the fungi, spores serve a function analogous to that of seeds in plants. Produced and released by specialized fruiting bodies, such as the edible portion of the familiar mushrooms, fungal spores germinate and grow into new individuals under suitable conditions of moisture, temperature, and food availability.

Many larger algae reproduce by spores and are also capable of sexual reproduction. A number of red algae species produce monospores (walled nonflagellate spherical cells) that are carried by water currents and form a new organism upon germination. Some green algae produce nonmotile spores, called aplanospores, whereas others produce motile zoospores, which lack true cell walls and bear one or more flagella. The flagella allow zoospores to swim to a favourable environment in which to develop, whereas monospores and aplanospores must rely on passive transport by water currents.

2. Read the text again and complete 10 questions.