BBC_Earth_Singapore_2017

PHOTOS: GETTY X4, SCIENCE PHOTO LIBRARY, SHUITTERSTOCK ILLUSTRATIONS: RAJA LOCKEY

WHAT CONNECTS...

...FROGS AND FRESH

MILK?

1.

Frogs, like all

amphibians,

have thin,

porous skin that

they can breathe

through. But

this also poses a

risk because it makes it easier

for bacteria to infect them.

2.

To protect

themselves, frogs

secrete substances

called cationic antimicrobial

peptides (CAMPs). Other

animals secrete CAMPs too, but

frogs produce much more,

including some peptides that

are effective against multi-

resistant bacteria.

3.

Milk goes off

because of

bacteria,

especially species

of Lactobacilli and

Pseudomonas. These ferment

the lactose in milk into lactic

acid, and hydrolyse milk

proteins into various unpleasant

tasting by-products.

4.

According to Russian folklore, putting

a live frog in milk would help it stay

fresh. Recent research

has found that

CAMPs from the

Russian brown

frog could kill the

bacteria in milk

and prevent it from

turning.

p

th

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s

QA

&

What is the biggest a moon can be in

relation to its mother planet?

A ‘moon’ is an astronomical body that

orbits a planet; the definition doesn’t

involve size. So, a ‘moon’ could be a small

rock or it could be as large as its ‘parent’.

However, similar-sized objects orbiting

each other are normally called ‘double’ (for

example, Pluto-Charon is often considered

a ‘double dwarf planet’). But the distinction

between ‘double’ and ‘parent-moon’

systems is not officially defined. Some

astronomers define a ‘parent-moon’

system as one that has the point about

which both objects orbit (the barycenter)

inside the larger object, but this distinction

is quite arbitrary because it depends on

both size and separation. AGu

Do seagulls drink seawater? And if so,

how do they deal with the salt?

All seabirds drink seawater – yet birds have

less efficient kidneys than mammals, and

so excess salt is even more toxic to them

than to us. Seabirds cope with this by using

specialised salt glands next to their eye

sockets. These look like miniature kidneys

and work in a similar way, pumping salt ions

out of the bloodstream against the normal

flow of osmosis. The extra-salty water drips

down the side of their beak. LV