9: Well big groups of birds are often found competing for food, causing fights and even death due to the fight. If a flock of birds from population A goes to population B, there would be more competition due to birds wanting food and nesting places that are good.
10: Many species evolve to suit environmental changes, but let's say this change in the environment was bad. Pollution, species of aggressive animals, which would eat the food the animals need and cause a downgrade in food leaving the area bare, and hunting, which would bring humans to the area and cause them to camp out, eat the animals and wild vegetables, such, can cause negative population changes. Due to these things birds could get sick and die off, causing population to go down. If trash and sewage are not cleaned up it could affect the birds food source and cause it to be bad for a long time, the aggressive animals would kill and eat the birds causing a continuous spiral of death, and hunting could cause them to die.
the average age for a male is the united states to stop growing is at the age of 16.
There are two main theories for the lack of organic material in desert soils. Firstly, the organic life in most deserts is so sparse that it cannot produce much organic matter. Secondly when things do die and decompose in the desert the heat and sunlight often bleach nutrients out of the matter before it is decomposes enough to be absorbed into soil
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Cell, nucleus, chromosome, gene
Answer: As a fertilized human egg divides, it first becomes a solid ball of cells, the morula. ... The cells of the outer layer of the blastocyst eventually form part of the placenta. Inside the ball is a small clump of cells, the inner cell mass, that will form all the tissues in the body.
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