Which of the following is NOT one of the structures of the excretory system?

Which of the following organelles is the principal and distinquishing feature of the eukaryotic cell? A. ribosomes B. chloroplas

dsp73

Answer:

E. Nucleus

Explanation:

All living organisms were classified into three major domains viz: Eukarya, Archaea and Bacteria. Eukarya are referred to as EUKARYOTES while the other two domains are collectively referred to as PROKARYOTES.

The major basis of this classification is the presence or absence of a membrane bound NUCLEUS. Eukaryotes are organisms characterized by the possession of a membrane-bound nucleus that houses their genetic material (DNA) while prokaryotes lack a nucleus and hence, their genetic material is found naked in the cytoplasm. Although, prokaryotic cells lack other membrane-bound organnelles like Chloroplast, mitochondria etc. but nucleus is the basis of this classification:

EU meaning TRUE, KARYA meaning NUCLEUS, hence Eukarya means organisms will true nucleus.

3 0

3 years ago

Choose the structures that most directly provide nutrients and remove wastes from osteocytes in compact bone.

Ber [7]

I had to look for the missing options of this question and here is my answer:

Osteocyte is the term that describes the cells of the bone. These cells are formed in the mesenchyme. Once the bone matures, the processes then take place inside the Lacunae and the Canaliculi, respectively. Therefore, we can say that the structure that allows the provision of nutrients and removal of wastes from osteocytes would be the canaliculi.

5 0

3 years ago

What ways do enzymatic catalysts increase the rates of reactions? they shift the reaction equilibrium toward the products they d

Elodia [21]

This is a question regarding how enzymes increase the rates of reactions. There are choices and the instructions is to check all that apply.

1. They shift the reaction equilibrium towards the products. 
2. They increase the concentration of the reactants. 
3. They lower the activation energy of the reaction. 
4. They decrease the free energy of a reaction. 
5. They promote the formation of a transition state.

The correct answers in this question are "they lower the activation energy of the reaction" and "they promote the formation of a transition state". Enzymes do not necessarily shift the the reaction equilibrium to the products, as there are reversible enzymatic reactions that can reverse the pathway back to the substrates. They do not increase the concentration of the reactants as the concentration of the reactants is an independent variable in this process. They do not decrease the free energy of activation as this is a constant in every reaction depending on the substrates and the products.

Enzymes do, however, lower the activation energy of the reaction meaning it will take less energy and effort for the substrates to reach the activation energy to transform it to its transition state then to the products. With this said, enzymes promote the formation of a transition state.

Attached is a simplified image on how enzymes work.