Answer:
All of these choices are correct.
Explanation:
Cell cycle is the process of growth and division of cell. It comprises of interphase and mitosis. In interphase the cell grows, replicates its genomic content and prepares itself for division. In mitosis the division occurs.
Cell cycle is controlled by a group of kinases called as Cyclin dependent Kinases (CDKs). They act by phosphorylating their substrates. They are of various types like Cdk1, Cdk2, Cdk4 etc. They become active when they bind to a regulatory protein called cyclin. They are also of various types like Cyclin A, Cyclin B, Cyclin C etc. Level of cyclin and corresponding CDK increases and decreases according to the stage of cell cycle. For example in S phase of cell cycle concentration of cyclin A and E shoots up. CDK2 is able to bind to these cyclin molecules and hence it becomes active.
Cell cycle has major checkpoints where the condition of cell is analysed before it proceeds to the next stage of cycle. If any abnormality is detected, repair mechanism is activated or the cell is killed. Checkpoints do not allow cell cycle to proceed in damaged cells.
p53 is a tumor suppressor protein which can halt cell cycle when it detects some abnormality in cell. It usually acts in G1/S checkpoint (before the DNA replication starts in cell) and G2/M checkpoint (before the cell division begins). Hence, all of the above statements are true.
Insects, arachnids, and crustaceans
Insects have 3 body segments. (head, thorax, abdomen)
Have a hard exoskeleton made of chitin.
Appendages be used for feeding, defense, sensory and reception.
Invertebrate phyla that obtains oxygen by using gills (marine) or air tubes (terrestrial.)
Use pincers and stingers as attack weapons to defend themselves
Characterized by having jointed legs, segmented bodies, and sometimes wings
Answer:
It needs protein channels known as Aquaporins.
Explanation:
These Aquaporins, also referred to as water channels, are membrane proteins which serve as passageways for water. Aquaporins facilitate the transportation of water and other neutral molecules across cell membranes.
Plants can make their own food by photosynthesising however, animals need to consume plants for energy/as food if their were no plants animals would starve. plants also provideanimals with oxygen as a waste product of photosynthesis which animals need to survive
