Answer:
Coal is a fossil fuel. It comes from the remains of plants that died about 100 to 400 million years ago. Coal is a non-renewable energy source because it takes millions of years to form
DNA replication<span> is </span>semi-conservative<span> because each helix that is created contains one strand from the helix from which it was copied. </span>
Answer:
Viruses cannot reproduce on their own, but inject their DNA into living cells in order to make copies of themselves.
Explanation:
A virus cannot reproduce itself outside the host because it lacks the complicated machinery that a [host] cell possesses.
<u>Answer:</u>
The series dilution method is the step wise dilution technique where the dilution factors remain constant in each step.
The advantages of using the series of dilution method over simple dilution are stated below:
<em>a) Aids in reduction of a dense culture of cells to a more usable concentration.</em>
<em>b) In every step of dilution the specific amount of bacteria is removed. </em>
<em>c) Helps in the estimation of concentration of an unknown sample.</em>
<em>This sums up the advantage of using the series dilution technique.</em>
Answer:
Hormone levels generally decrease.
Explanation:
<em>The graph showed that hormone levels after ovulation generally decrease.</em>
The menstrual cycle of women generally have 3 phases which include:
- <em>The follicular phase</em>
- <em>The ovulatory phase</em>
- <em>The luteal phase</em>
The follicular phase is characterized by low levels of oestrogen and progesterone and a slightly high level of follicle stimulating hormone which ensures that follicles within the ovary develop.
The ovulatory phase is characterized by a surge in the luitenizing hormone (which stimulates the release of eggs) and follicle stimulating hormone with a decrease in the level of oestrogen and a gradual increase in the level of progesterone.
The luteal phase is characterized by a general decrease in the levels of luitenizing hormone and follicle stimulating hormone while oestrogen level may remain high.