Answer:
every answer of yours is correct
Answer:
Humans cannot occupy the lowest levels.
Explanation:
Answer:
stigma
Explanation:
Pollination occurs when pollen grains from the anther land on a stigma. After pollen grains land on the stigma, a pollen tube grows from the pollen grain, through the style, and into the ovary. Sperm cells inside the pollen grain travel down the pollen tube and into the ovary which contains the ovules.
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.
