Answer:
Mass extinction is when biodiversity or species in a living habitat decreases to about three-fourths of its original number or to none. Such an event is identified by a sharp change in the diversity and abundance of multicellular organisms. It occurs when the rate of extinction increases with respect to the rate of speciation. Mass extinctions are usually associated with organisms that are macroscopic rather than microscopic. Examples of mass extinctions are Permian extinction of marine species, and Cretaceous extinction of various species, including dinosaurs.
The correct answer is: a gene may represent only a millionth of the cell's DNA.
The method used to amplify DNA fragments is called polymerase chain reaction (PCR). PCR is a technique used in molecular biology to produce thousands to millions of copies of a single targeted DNA sequence. When studying a specific gene, the scientist needs to be able to target and focus only on the DNA sequence which constitutes this exact gene. However, a gene is only a very small portion of an organism's genome. Therefore, the scientist uses PCR to amplify this DNA sequence and produce a large number of copies.
He saw that not only was there yellow seeded pea plants, but green seeded pea plants. Recessive traits that seemed to have disappeared in the first cross reappeared here.
Explanation:
1. What is a longitudinal wave?
- A wave vibrating in the direction of propagation
- This is also called "pressure waves"
- Example: Sound waves, ultrasound waves
2. When you hear a sound wave through the air, what are you detecting?
We are detecting the sound wave through the ears. There is a part called ear drum present inside the ear and it turn contains 3 bones which makes us to hear the sounds. When sound waves enters, the ear drum vibrates.
3. In which direction does the material vibrate, as energy travels through it?
The direction is perpendicular to the direction of energy transport.
4. When a wave transmits, or transfers, energy, do the individual molecules or particles also move from one end to the other?
Yes, the particles move from one end to other.