D) laboratory experiments because every experiment needs a control and a variable.
A memoir describes the biography that is personally written in which all life events are captured in words with his memory so it is not considered historical document because
<span> a memoir relies largely on the writer's memories
</span>because it rely on writer memory and he can also forget something
so correct option is C
hope it helps
Answer:
1.
Explanation:
Xylem cell is a plant vascular tissue that conveys water and dissolved minerals from the roots to the rest of the plant and also provides physical support. Xylem tissue consists of a variety of specialized, water-conducting cells known as tracheary elements.
2. Phloem is the vascular tissue in charge of the transport and distribution of organic nutrients. The phloem is also a pathway to signaling molecules and has a structural function in the plant body.
3. Stomata are composed of a pair of specialized epidermal cells referred to as guard cells. Stomata regulate gas exchange between the plant and environment and control water loss by changing the size of the stomatal pore.
4. Guard cells optimize leaf gas exchange in response to changing environmental conditions and their turgor is controlled by alterations in atmospheric CO2 concentration, light intensity, humidity, and the drought hormone abscisic acid.
Answer: C
Explanation:
Pyruvate dehydrogenase complex (PDH) is covalently modified by phosphorylation by PDH kinase and dephosphorylation by PDH phosphatase.
The dephosphorylated form of the enzyme is active. Hence activators of PDH kinase like ATP, NADH and acetyl CoA inhibits the PDH reaction
PDH phosphatase is activated by Ca++, Mg++ and AMP; this will increase the rate of PDH reaction where as PDH kinase is inhibited by Ca++. When there is adequate ATP and acetyl CoA the enzyme is inhibited.
