Answer:
At the beginning, aerobic respiration is used by his legs to generate energy when there was still sufficient oxygen intake for energy to be generated via oxidative phosphorylation.
Towards the end of the ride, his legs are generating energy through anaerobic respiration due to insufficient oxygen intake to keep up with the energy requirement of his muscles as he cycles continuously. Through anaerobic respiration, pyruvate from glycolysis is converted to lactate by lactate dehydrogenase instead of being channelled to the mitochondria for oxidative phosphorylation. The accumulation of lactate in his muscles is what causes the pain in his leg. After he stops the activity, the pain would reduce as lactate is transported to the liver to be reconverted back into pyruvate.
The upper surface of the fern leaves known as fronds are shiny as a result of
the production of a waxy cuticle.
<h3>What is a Fern? </h3>
A fern is a type of vascular plant which doesn't produce flowers and
reproduces with the aid of spores. Ferns are mostly found in shaded areas
and have a characteristic shiny surface.
The shiny surface is however as a result of the production of waxy cuticles
by the epidermis of the leaves. The waxy cuticle helps to prevent the plant
from water loss.
Read more about Ferns here brainly.com/question/18530534
First fill in the blank: Restriction enzymes (restriction endonucleases)
Second fill in the blank: Restriction sites
Thymus.
Hope that is an answer.
(and that I helped) :')