Answer:
e.) If exposure to cowpox gives immunity to smallpox in milkmaids, then milkmaids have a natural immunity and their blood should be used to develop a smallpox vaccine.
Explanation:
- Milkmaids who suffered from cowpox did not suffer from smallpox i.e. they were immune to the disease.
- If milkmaids did not suffer from smallpox then there must be some element of immunity that they received once they had recovered from cowpox, this would likely be found in their blood as antibodies.
Increasing the temperature will cause an increase in the kinetic energy of molecules which will change its state to gas.
Answer:
The cell cycle has three phases that must occur before mitosis, or cell division, happens. These three phases are collectively known as interphase. They are G1, S, and G2. The G stands for gap and the S stands for synthesis.
Explanation:
Answer:
e. None of these
Explanation:
The immune deficiency viruses (HIV) are retroviruses that use a reverse transcriptase (RT) enzyme to produce a single-stranded DNA (ssDNA) from an RNA template. The reverse transcription allows retroviruses to replicate their genetic material, which is integrated into the host's genome as a double-stranded linear DNA molecule in a similar way to the mechanism of insertion used by endogenous retrotransposons. The synthesis of DNA is started by cellular tRNAs (tRNA3Lys) that are packaged into the virion. After reverse transcription, the HIV DNA enters the nucleus of CD4 immune cells (also known as CD4+ T cells), and then it integrates into the genome to coopt the host's cell machinery for its own replication.
1. plants do not need and complex excretory organ because it creates a very small amount or nitrogenous waste.