The fertilized egg begins a rapid descent to the uterus. The period of rest in the tube appears to be necessary for full development of the fertilized egg and for the uterus to prepare to receive theegg. ... At the end of this transition period, the embryo becomes a mass of very organized cells, called a blastocyst.
Answer:
The tail and the caudal fin are the chief locomotory organs of fish and are used for rapid swimming during which tail is lashed from side to side by "alternate contraction and relaxation" of the myomeres on the two sides of the vertebral column.
Explanation:
Answer: See below
Explanation:
Solar energy: Advantages: Solar energy is pollution free and causes no greenhouse gases to be emitted after installation. Disadvantages: Although solar energy can still be collected during cloudy and rainy days, the efficiency of the solar system drops.
Wind energy: Advantages: It doesn't pollute air like power plant relying on combustion of fossil fuel. Disadvantages: Wind turbines can be a threat to wildlife (e.g. birds, bats).
Hydroelectric energy: Advantages: Hydroelectric energy is fueled by water, so it's a clean fuel source, meaning it won't pollute the air like power plants that burn fossil fuels, such as coal or natural gas. Disadvantages: Electricity generation and energy prices are directly related to how much water is available. A drought could potentially affect this.
Answer: Infection occurs when the host is exposed to pathogens. virus uses the cell's metabolism, and replicates itself while destroying the cell or changing the cell's genetic makeup.
Explanation:
- A virus is a miniscule pocket of protein that contains genetic material.
- Viruses pose a considerable challenge to the body’s immune system because they hide inside cells.
- This makes it difficult for antibodies to reach them. Some special immune system cells, called T-lymphocytes, can recognise and kill cells containing viruses, since the surface of infected cells is changed when the virus begins to multiply.
- Many viruses, when released from infected cells, will be effectively knocked out by antibodies that have been produced in response to infection or previous immunisation.
- Antibiotics are useless against viral infections. So antiviral drugs work differently to antibiotics, by interfering with the viral enzymes instead.
Hence virus are the pathogen that use the cell's metabolism. And replicate itself while destroying the cell or changing the cell's genetic makeup. viruses are so simple that they use their host cells to perform their activities for them
Learn more about virues :
brainly.com/question/17173059
#SPJ4
