Only 200 out of 2 000, 000 sperm cells reach the ovum. And only one (in exception to very rare cases of two) sperm cells actually participate in the process of fertilization. In comparison, an average female only produces 400 of egg cells during their lifetime, but the eggs cells are significantly larger than sperm cells.
Both chicken pox and shingles are caused by varicella zoster.
Explanation:
Shingles and chicken pox both occurs by the attack of the virus, varicella zoster.
Cause: - The chicken pox spreads through the infectious elements in a person’s cough, sneeze and breathing. The shingles occur when this virus gets reactivated.
Portal entry: - Chicken pox virus enters through the tract of respiration and shingles enter from a person who already have it.
Signs & Symptoms: - Pox includes- fever, blister like itchy rash and shingles include- blister rash which has a distribution that is like a band.
Incubation period: - Pox can stay for a minimum of 15 days approximately and shingles too last for few weeks.
Treatment and prevention: - Both include treatment of antiviral and both can be prevented by avoiding infected people and increasing body immunity etc.
Answer:
each new cell needs a DNA copy, which serves as instructions on how to function as a cell. DNA replicates before a cell divides. The replication process is semi-conservative, which means that when DNA creates a copy, half of the old strand is retained in the new strand to reduce the number of copy errors.
Explanation:
The mechanism in which organisms best suited for their environment survive
and reproduce <u>NATURAL SELECTION.</u>
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Explanation:
When individuals in a population compete for resources or live in their environment, the individuals with the slightest advantage over the others have an increased chance of reaching maturity and reproducing to passing down their genes to the next generations.
Natural selection works on the variations of the population to ‘select’ the best alleles of genes in the population that offer an advantage in ‘survival for the fittest’. This how natural selection fits a population to its environment. The greater the variation within a population, the higher its capacity to adapt to changes in the environment.
Learn More:
For more on natural selection check out;
brainly.com/question/1184863
brainly.com/question/875198
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Answer:
<em>The correct option is B) Freshwater snails and small fish</em>
Explanation:
As we can see from the food web, the fresh water snails and the small fishes both feed on algae and water plants as their source of food hence, both these organisms feed on the same food.
Other options, like option C, is not correct because water boatman and water plants do not feed on the same sources. Water boatman feeds on reeds whereas water plants do not. Water plants will make their own food.
