Temperature changes in the environment affect most of the animals which are

Options

A. homeothermic
B. aquatic
C. poikilothermic
D. desert living

Explanation

To answer the question regarding how temperature changes in the environment affect various groups of animals, we can analyze each option provided:

1. **Homeotherms**: These are organisms that can maintain a stable internal body temperature regardless of external environmental conditions. Examples include mammals and birds. Since they can regulate their body temperature, they are less affected by temperature changes in the environment.

2. **Aquatic Organisms**: These organisms live in water. Water has a high heat capacity, which means it can absorb a lot of heat without changing temperature quickly. Therefore, aquatic organisms are also less affected by immediate temperature changes in their environment compared to terrestrial organisms.

3. **Poikilotherms**: These are animals that cannot regulate their body temperature internally and instead rely on the external environment to determine their body temperature. Their body temperature fluctuates with the ambient temperature, making them highly susceptible to temperature changes. Examples include reptiles, amphibians, and many fish. Due to their dependence on environmental temperatures, poikilotherms are significantly affected by global warming and other temperature fluctuations, leading to changes in their activity levels and even extinction in some cases.

4. **Desert Living Organisms**: These organisms have adapted to survive in extreme temperatures, both hot and cold. They possess various adaptations that allow them to cope with temperature changes in their environment. While they may face challenges, they are generally well-equipped to handle temperature fluctuations.

Based on this analysis, the group of animals most affected by temperature changes in the environment is **poikilotherms** (option 3). They are unable to maintain a stable internal temperature and are therefore vulnerable to the impacts of global warming and other temperature changes.

### Step-by-Step Solution:
1. **Identify the groups of animals**: Homeotherms, aquatic organisms, poikilotherms, and desert living organisms.
2. **Understand the characteristics of each group**:
- Homeotherms maintain a stable body temperature.
- Aquatic organisms are less affected due to water's high heat capacity.
- Poikilotherms cannot regulate their body temperature and are affected by environmental changes.
- Desert organisms have adaptations to survive in extreme temperatures.
3. **Evaluate the impact of temperature changes**:
- Homeotherms are less affected.
- Aquatic organisms are also relatively unaffected.
- Poikilotherms are significantly affected due to their inability to regulate temperature.
- Desert organisms have adaptations to cope with temperature changes.
4. **Conclude**: The group most affected by temperature changes is poikilotherms.