Answer: A change in the sequence of amino acids determined by the gene
For the answer to the question above, the Endocytosis is a process that allows a cell to engulf molecules in the entirety of the molecule and surround those molecules in a membrane. Transport is when a small molecule <span>can actively transport through a cellular membrane and come out again. I hope this helps</span>
<span>Blockage of the Cerebral Artery can reduce blood supply to the brain, causing a stroke (Ishcemic Stroke)
Blood is carried to the brain by two pair of arteries, i) The Internal Carotid arteries, ii) The Vertebral arteries.
Stroke is a neurovascular condition affecting blood vessels in the brain. There are two types of Stroke i) Ischemic Stroke ii) Hemorrhagic Stroke.
In Ischemic stroke occlusion of a cerebral artery causes the damage to brain tissue dependent on blood supply from the affected vessel</span>
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.
Answer:
<em>The total amount of energy transferred during photosynthesis for this ecosystem equals</em><em> 260,000 kcal/m2/yr.</em>
Explanation:
To answer this question, we need to know that
- gross primary productivity (GPP) = energy captured and converted into chemical energy during photosynthesis
- net primary productivity (NPP) = difference between GPP and respiration rate
So, to calculate GPP we need to sum NPP to Respiration rate. This if,
NPP = 165,000 kcal/m2/yr
R = 95,000 kcal/m2/yr
NPP = GPP – Respiration
Then,
GPP = NPP + R
GPP = 165,000 kcal/m2/yr + 95,000 kcal/m2/yr
GPP = 260,000 kcal/m2/yr
