BMI<span> (body mass index), which is based on the height and weight of a person, is an </span>inaccurate<span> measure of body fat content and does </span>not take into account muscle mass, bone density, overall body composition, and racial and sex differences. <span>BMI is a substitute measure of body fatness because it is a measure of excess </span>weight<span> rather than excess body </span>fat<span>. Factors such as age, sex, ethnicity, and muscle mass can influence the relationship between BMI and body </span>fat<span>.</span>
The correct answer is option (d) They allow the exchange of gases between cells in the leaf and the external environment.
Stomata are the tiny openings present in the epidermis (outer layer of cells) of the leaf. They have a pore which is guarded by the guard cells which controls the opening and closing of the stomata. Air enters and exits through the stomata.
The main funtion of stomata is to facilitate the gaseous exchange. The gas exchange that occurs when the stomata are open helps in the process of photosynthesis. During photosynthesis, carbon dioxide is taken in from the atmosphere and oxygen is released as a by-product of photosynthesis. The glucose produced is converted into the starch and stored in the leaves.
Also, water vapour diffuses through the stomata into the atmosphere by a process called the transpiration.
Thus, stomata are the structures that are mainly involved in the gaseous exchange between the cells of the leaf and the atmosphere.
Answer:
In their experiments, Hershey and Chase showed that when bacteriophages, which are composed of DNA and protein, infect bacteria, their DNA enters the host bacterial cell, but most of their protein does not. Hershey and Chase and subsequent discoveries all served to prove that DNA is the hereditary material.
Photosynthesis and respiration are reactions that complement each other in the environment.
They all contain carbonyl groups. DNA has carbonyl groups in it's nucleotide ring structures. Every amino acid in a protein has a carbonyl group in its backbone structure. Fats too have carbonyl groups in their structures attached to hydrocarbon chains
