The attached body form of Cnidarians would be polyp
Answer:
The correct option is A. Steroid hormones exert their action by entering the nucleus of a cell and initiating or altering the expression of a gene.
Explanation:
Steroid hormones are derived from cholesterol and regulate multiple biological processes. All steroid hormones exert their action by crossing the plasma membrane and by binding with their respective intracellular receptors. They stimulate cell growth in a very different way, their lipophilic nature gives them the ability to cross lipid barriers, so, without the need for extracellular signals, these hormones can easily enter the cell, cross the cytoplasm and reach the nucleus. There they bind to specific receptors that are associated with DNA promoter regions, modifying their structure and promoting the expression of the genes under their control.
Answer:
Cytoskeletal elements play important roles in cell division. The mitotic spindle apparatus is made of "microtubules" and pulls sister chromatids apart, whereas the contractile ring is made of "actin filaments" and required for the separation of daughter cells at the end of the mitotic phase of the cell cycle.
Explanation:
The three chief organizational apparatuses of the cytoskeleton are microtubules (formed by tubulins), microfilaments (formed by actins) and intermediate filaments. All three apparatuses cooperate with each other non-covalently. The cytoskeleton is composed of protein filaments and is found throughout the inside of a eukaryotic cell. The cytosol is the main component of the cytoplasm, the fluid that fills the inside of the cell. The cytoplasm is everything in the cell except for the cytoskeleton and membrane-bound organelles.
Answer:
A substance that speeds up a chemical reaction—without being a reactant—is called a catalyst. The catalysts for biochemical reactions that happen in living organisms are called enzymes. Enzymes are usually proteins, though some ribonucleic acid (RNA) molecules act as enzymes too.
Explanation:
enzymes don't change their own reaction. That's because they don't affect the free energy of reactants or the products.
Answer: they are all prokaryotes
Explanation: because they all lack a nucleus to retain their DNA
