Population is a group of individuals of a single species living in a given area. It includes spatial arrangement, genetic variation and the dynamics including natality, mortality, biotic potential, carrying capacity, etc. Population structure includes features as density, abundance, spacing, genetic variations. The genetic structure reveals genetic variations and population size.
There is more competition for survival between:

Options

A. Different animals of same niche
B. Same animals of same niche
C. Different animals of different niche
D. Same animals of different niche.

Explanation

To answer the question regarding competition for survival among different groups of animals, we need to analyze the options provided and understand the concept of a niche.

### Step-by-Step Solution:

1. **Understand the Definition of a Niche**:
- A niche refers to the functional role of an organism in its ecosystem, which includes its habitat, resource use, and interactions with other organisms.

2. **Identify the Types of Competition**:
- Competition occurs when organisms vie for the same resources. The intensity of competition is influenced by how similar the organisms are in terms of their ecological roles (niches).

3. **Evaluate the Options**:
- **Option A**: Different animals of the same niche - They may compete, but they are different species, which can reduce direct competition.
- **Option B**: Same animals of the same niche - This option suggests that individuals of the same species competing for the same resources will experience the highest level of competition.
- **Option C**: Different animals of different niches - There would be minimal competition since they utilize different resources and occupy different roles in the ecosystem.
- **Option D**: Same animals of different niches - There would be some competition, but it would not be as intense as between the same animals of the same niche.

4. **Determine the Best Answer**:
- Based on the analysis, **Option B** (same animals of the same niche) is the correct answer. This is because individuals of the same species have identical resource requirements, leading to increased competition for survival.

### Final Answer:
**B. Same animals of the same niche**