Question

что является общим в строении простейших? почему ученые утверждают что у животных и растений были общие предки? как связаны между собой способ питания и образ жизни простейшего?

Answer 1

То, что ученые утверждают что у животных и растений были общие предки можно обьяснить на примере Эвглены зелёной. У нее присутствует 2 вида питания: автотрофный ( фотосинтез, как у растений ) и гетеротрофный ( захватывание пищи, как у животных ). ЕЕ из-за этого часто называют переходным звеном между растениями и животными.

 

Общим является то, что у них весь организм состоит из одной клетки. Они способны обьединятся в колонии, но так как клетки не выполняют специальные функции, они не есть одним организмом. У них есть органы передвижения ( джгутики, реснички, параподии ), они не имеют сложного строения, многие проживают в водной среде.

 

На примере той же Эвглены зелёной - для того, чтобы выполнять фотосинтез ей нужна солнечная енергия, поэтому она находится ближе к поверхности.

 

Извини за грамматические ошибки, переводила как могла) 

Answer 2

Common Features in the Structure of Simple Organisms

The simplest organisms, such as unicellular organisms, share several common features in their structure. These features include:

1. Cellular Organization: Simple organisms are composed of one or a few cells. These cells are the basic units of life and carry out essential functions such as metabolism, reproduction, and response to stimuli.

2. Cell Membrane: All simple organisms have a cell membrane that separates the internal environment of the cell from the external environment. The cell membrane controls the movement of substances in and out of the cell.

3. Genetic Material: Simple organisms contain genetic material, usually in the form of DNA or RNA, which carries the instructions for the organism's development, growth, and reproduction.

4. Metabolism: Simple organisms have metabolic processes that allow them to obtain energy from their environment and use it to carry out essential life functions. These processes may include the breakdown of nutrients, the production of energy-rich molecules like ATP, and the elimination of waste products.

5. Reproduction: Simple organisms reproduce to ensure the survival of their species. They may reproduce asexually, through processes such as binary fission or budding, or sexually, through the fusion of gametes.

6. Response to Stimuli: Simple organisms can respond to changes in their environment. They may exhibit behaviors such as movement towards or away from stimuli, changes in growth patterns, or alterations in metabolic activity.

These common features in the structure of simple organisms are essential for their survival and adaptation to their environment.

Common Ancestors of Animals and Plants

Scientists assert that animals and plants share common ancestors based on the evidence gathered from various fields of study, including paleontology, comparative anatomy, and molecular biology. The theory of evolution, proposed by Charles Darwin, provides a framework for understanding the common ancestry of living organisms.

According to the theory of evolution, all living organisms are believed to have descended from a common ancestor through a process of gradual change over millions of years. This common ancestor is thought to have been a simple organism, similar to modern-day unicellular organisms.

The evidence supporting the common ancestry of animals and plants includes:

1. Fossil Record: Fossils of ancient organisms provide evidence of transitional forms that show similarities between animals and plants. These fossils demonstrate the gradual changes in structure and form over time.

2. Comparative Anatomy: Comparative anatomy involves studying the similarities and differences in the structure of different organisms. By comparing the anatomical features of animals and plants, scientists have identified shared characteristics that suggest a common ancestry.

3. Molecular Biology: Molecular studies, such as DNA sequencing and analysis, have revealed similarities in the genetic material of animals and plants. These similarities indicate a common genetic heritage and support the idea of a shared ancestry.

4. Embryology: The study of embryonic development has revealed similarities in the early stages of development between animals and plants. These similarities suggest a common evolutionary origin.

While the exact details of the common ancestors of animals and plants are still the subject of ongoing research, the evidence from multiple scientific disciplines strongly supports the idea of shared ancestry.

Relationship Between Feeding Habits and the Lifestyle of Simple Organisms

The feeding habits and lifestyle of simple organisms are closely interconnected. The way an organism obtains its food is often influenced by its overall lifestyle and ecological niche.

1. Feeding Habits: Simple organisms exhibit a variety of feeding habits. Some organisms, such as autotrophs, can produce their own food through processes like photosynthesis. Others, known as heterotrophs, rely on consuming other organisms or organic matter for their nutrition.

2. Lifestyle: The lifestyle of a simple organism refers to its overall behavior, habitat, and ecological interactions. For example, some simple organisms may be free-living, meaning they can move and obtain food independently. Others may be parasitic, relying on a host organism for their nutrition. Some may be symbiotic, forming mutually beneficial relationships with other organisms.

The relationship between feeding habits and lifestyle can be seen in examples such as photosynthetic organisms. These organisms, such as certain types of algae and bacteria, have a lifestyle that involves capturing sunlight and converting it into energy through photosynthesis. This lifestyle allows them to produce their own food and thrive in environments with access to sunlight.

On the other hand, heterotrophic organisms, such as certain types of protozoa, obtain their food by consuming other organisms or organic matter. Their lifestyle may involve actively seeking out prey or scavenging for food in their environment.

In summary, the feeding habits of simple organisms are closely tied to their lifestyle and ecological niche. The way an organism obtains its food is influenced by factors such as its ability to produce its own food, its interactions with other organisms, and its habitat.