the measurement of small quantities of antigen.- (i) Heat loss or gain is directly related to exposed
surface area. Shorter extremities are an adaptation
to reduce exposed surface area in order to reduce
heat loss in cold regions. Therefore, arctic hare (Lepus
arcticus) found in tundra region, has smallest external
ear size as small size of the ears helps to reduce heat
loss in cold conditions.
(ii) Given figure shows the North American hares, in which
there is a good correlation between external ear size
and average temperature experienced by different
species. Here, populations of North American hares
from different latitudes follow Allen's rule. Increasing
latitude indicates decreasing temperatures. Allen's
rule states that "animals of colder areas have shorter
extremities (leg tail, ears, feet) as compared to animals
of warmer areas".
5.(i) Structure labelled A is b-pleated secondary structure.
In b-pleated secondary structure, two or more
polypeptide chains get interconnected by hydrogen
bonds. A sheet is produced, therefore this structure
is called pleated sheet or b-pleated sheet. Adjacent
strands of polypeptides may run in same direction or
in opposite directions. The adjacent strands are held
together by hydrogen bonds formed between –CO
and –NH groups to form sheet.
(ii) The differences between enzyme cellulase and its
substrate cellulose are:Cellulase Cellulose- Made up of amino
acids.
Made up of b-glucose.- Peptide bond between
monomers.
Glycosidic bonds (b1-4)
between monomers.- Ionic bonds, hydro-
phobic interactions
and disulphide bonds
are present.
These are not present.- No rotation of amino
acids.
Alternate b- g l u c o s e
rotated through 180°.- Globular in nature. Fibrous in nature.
nnHave you recently felt like you're out of focus? Do you find it
difficult to concentrate on your work? Experts say that some
foods contain essential vitamins and minerals that help you
concentrate better. Here's a list...AVOCADO
Avocados are said to be one of the most effective foods
when it comes to improving
concentration. They contain
monounsaturated fats that
boost the nerves in your
brain, which are responsible
for taking in information
and registering facts and
events.
GREEN VEGETABLES
While green leafy veggies
are good for overall health,
they are exceptionally good
for your brain. Spinach,
broccoli, iceberg lettuce,
kale and cabbage are
packed with antioxidants
as well as B vitamin folate,which will improve your ability to focus better.
PEANUTS
This humble nut may seem like a not-so-important snack but
studies say that peanuts contain fibre and a host of minerals
and vitamins that help you think more clearly and focus
better.DRY FRUITS
Have a handful of dry fruits daily,
and see how much they benefit
you. If you don't want to eat them
plain, add them to your breakfast
cereal. They will increase energy
levels and help you pay more
attention to daily tasks.BLUEBERRIES
Add blueberries to your snacks,
smoothies or breakfast regularly.
The fibre content in them will
make sure your attention doesn't
waver. And since they're low cal,
you needn't worry about any
weight gain either.
Courtesy : The Times of India