Answer:
Explanation:
Each chromosome represents a twin.like pairs of socks.
This is an analogous problem: you have 2 pairs of socks, one white, one black. Each of the sock is tailored to a specic foot, right or left. How many different ways can the socks be mixed and matched , one for each foot?
Here are the possibilities : left = black, right = black is one such match. Left = white, right = black is another.
so also we will have 23 chromosome pairs
If the sperm gametes that fertilizes an egg has an XX chromosomes, it will form female offspring. X is a female, XY is a female, Y is a male and XX is a female.
The spinal cord and the brain make up the central nervous system, and spinal cord nerves carry most messages between the brain and the rest of the body.
The vagus nerve carries the signal from the brain to the heart.
Answer:
<em>The correct option is d) an ecotone</em>
Explanation:
An ecotone can be described as an area of transition between two different biomes. An estuary can be described as an ecotone where the river water meets the seawater. The freshwater biome mixes with the seawater biome in an estuary. Unique plants and animals are grown in an estuary which are adapted to live in such an environment. The water present in an estuary is termed as brackish water. Hence, the correct option is d.
Answer:
d.They are still very common ,but threatened with increasing harvesting for timber.
Explanation:
Brazil's Araucaria trees:
These trees are very soft and can be cut so easily.Brazilian pines is also know as Araucaria tree.
Before 1950's or 60's the number of trees were more but now due to harvesting the number of trees become less.The these trees are used for timber and for glue also.
In the present time the availability of these trees threatened with increasing harvesting for timber.
So the our option d is correct.
