2. This statement rephrases the principle of uniformitarianism. The correct option among all the options that are given in the question is the third option or the penultimate option.
3. A worm would would stand a poor chance of being fossilized because worms have no hard parts. The correct option among all the options that are given in the question is the third option.
It's the cell, can't you tell
the cell membrane acting like a bouncer at a club door
certain allowed in while others are ignored
the nucleus is the center of them all
it is the brain of the cell which leaves it no choice but to always be on the ball
the mitochondria work hard to produce atp
it allows us humans to run around at free
next comes the vacuoles the storage center
items important are only allowed to enter
Answer:
found lining many areas that contact the external environment
plays a role in protection
Explanation:
Explanation: Epithelial tissue is composed of cells laid together in sheets with the cells tightly connected to one another. Epithelial layers are avascular, but innervated. Epithelial cells have two surfaces that differ in both structure and function.
Diagram found elsewhere attached
Answer:
Clockwise from bottom
3. formation of mRNA in the nucleus
6. secretion of hormone by tissue
4. initiation of DNA replication because of a signal given by the hormone
2. synthesis of protein molecule by mRNA and tRNA
1. secretion of protein by the cell
5. binding of the hormone molecule with its receptor of the cell
Explanation:
The tissue in the top left releases a hormone. For example, a steroid hormone such as estrogen, which can impact gene expression at the level of transcription. This hormone then travels to a different cell to carry out its function. The hormone is able to enter the cell and binds receptors which recognise it. In this case, these receptors are present in the nuclear envelope. When the hormone has bound the receptor, it initiates a signalling cascade that the cell responds to.
In this case, the effect of the signal from the hormone is to initiate DNA replication. This is a common effect of hormones such as growth factors that signal the cells to proliferate.
The initiation of the signalling can also affect how genes are expressed. In this case, an mRNA is produced in the nucleus, which is created as a result of transcription. This mRNA molecule then moves to the cytoplasm, where it becomes translated into a polypeptide sequence at a ribosome, with the help from transfer RNAs (tRNAs).
This polypeptide forms a mature protein by progressive folding and potential modifications, and is released by the cell to perform its functions.