Question

40 баллов! Тест по биологии (6 класс) Половое размножение покрытосеменных растений Изучив *параграф* << Половое размножение покрытосеменных растений>> и рисунки учебника , выполните задания. Задание #1 Ответить на вопросы 1. Какое строение имеют: пыльцевые зерна,пыльца,семязачаток? 2. Почему у цветковых растений оплодотворение называют двойным? 3.Почему перекрестное опыление больще распространено , чем самоопыление? 4.Распределить ветроопыляемые и насекомоопыляемые растения. Ветроопыляемые: Насекомоопыляемые: Растения: берёза,львиный зев,клевер,тополь,дуб. Задание #2 Заполните таблицу Признаки насекомоопыляемых растений | Признаки ветроопыляемых растений .... Задание #3 Рассмотрите рисунок #1 , на котором изображен цикл развития цветкового растения.Подпищите , что изображено под каждой цифрой. (3 задание не надо писать!)

Answer 1

Ветроопыляемыи растения: ольха,лещина,осина,шелковица.
насекомого пылевые растения:шиповник,одуванчик,яблоня,вишня,черешня,абрикос

Answer 2

I'm sorry, but I am unable to view or access specific images or diagrams. However, I can provide you with information about the questions you have asked. Let's go through them one by one:

Question 1:

1. What is the structure of pollen grains, pollen, and ovule?

Pollen grains are the male reproductive structures of flowering plants. They are produced in the anthers of flowers. Each pollen grain consists of a protective outer layer called the exine and an inner layer called the intine. The exine is made up of a tough substance called sporopollenin, which helps protect the pollen grain during its journey to the female reproductive structure. The intine contains the cytoplasm and the male gametes.

Pollen is the collective term for all the pollen grains produced by a plant. It is the male gametophyte of flowering plants.

The ovule is the female reproductive structure of flowering plants. It is located within the ovary of a flower and contains the female gametophyte. The ovule consists of several layers, including the integuments, which protect the developing embryo sac.

Question 2:

2. Why is fertilization in flowering plants called double fertilization?

Fertilization in flowering plants is called double fertilization because it involves the fusion of two male gametes with two female gametes. One male gamete fuses with the egg cell to form the zygote, which develops into the embryo. The other male gamete fuses with two polar nuclei to form the endosperm, which provides nourishment to the developing embryo. This unique process of double fertilization ensures the successful development of both the embryo and the endosperm.

Question 3:

3. Why is cross-pollination more common than self-pollination?

Cross-pollination, or the transfer of pollen from the anther of one flower to the stigma of another flower, is more common than self-pollination in flowering plants. This is because cross-pollination promotes genetic diversity, which is beneficial for the survival and adaptation of plant populations. By receiving pollen from a different plant, there is a higher chance of introducing new genetic variations and avoiding inbreeding depression. Self-pollination, on the other hand, leads to limited genetic diversity and can result in reduced vigor and adaptability in offspring.

Question 4:

4. Categorize the following plants as wind-pollinated or insect-pollinated: birch, snapdragon, clover, poplar, oak.

- Wind-pollinated plants: birch, poplar, oak. - Insect-pollinated plants: snapdragon, clover.

Question 5:

Unfortunately, I cannot provide information on the third task as it requires the analysis of a specific image.

Please let me know if there is anything else I can help you with!