"The earliest evidence of life on Earth comes from fossils discovered in Western Australia that date back to about 3.5 billion years ago. These fossils are of structures known as stromatolites, which are, in many cases, formed by the growth of layer upon layer of single-celled microbes, such as cyanobacteria. (Stromatolites are also made by present-day microbes, not just prehistoric ones.)
The earliest fossils of microbes themselves, rather than just their by-products, preserve the remains of what scientists think are sulfur-metabolizing bacteria. The fossils also come from Australia and date to about 3.4 billion years ago
Bacteria are relatively complex, suggesting that life probably began a good deal earlier than 3.5 billion years ago. However, the lack of earlier fossil evidence makes pinpointing the time of life’s origin difficult (if not impossible)."
(credit: https://www.khanacademy.org/science/biology/history-of-life-on-earth/history-life-on-earth/a/hypotheses-about-the-origins-of-life)
<u>and for the love of god please change that profile picture</u>
Answer: 1 Lysosomes and peroxisomes, Microtubules, Endoplasmic reticulum, Mitochondria
2 The role of the nucleus of a eukaryotic cell is to control the cell. Because it contains most of the cell's DNA, which is encoded with genetic instructions, the nucleus controls which proteins the cell makes.
3 The rough endoplasmic reticulum has ribosomes on its surface. This is what give the RER a "rough" appearance. The smooth endoplasmic reticulum (SER) does not contain ribosomes. The Smooth ER looks more like tubes. The SER helps in the storage of proteins and lipids.
4 Secretory vesicles contain materials that are to be excreted from the cell, such as wastes or hormones.
Transport vesicles move molecules within the cells.
Vacuoles are vesicles that contain mostly water.
hope this helps
Transcriptional activator proteins may control the level of transcription of eukaryotic genes by bind to promoters that enhance or regulate the transcription.
Repressors may control the level of transcription of eukaryotic genes by binding to DNA sequences that work either as silencers or promoters in order to inhibit the transcription impeding the access to where the transcriptional activator proteins may bind.
The above statement is false.
A complete protein is a source of protein that contains an adequate proportion of all nine essential amino acids necessary for the dietary needs of humans.
For example, meat, seafood, eggs and dairy are all complete proteins, while plant foods like beans, whole-grains and brown rice are incomplete proteins.
