Video Transcript
A female tiger and a male lion are
mated in a zoo. Which of the following is correct
about the cub they produce? The cub will not survive longer
than four to five years. The cub will be able to reproduce
successfully with both lions and tigers. The cub is likely to be sterile and
unable to have offspring of its own. The cub will be classified in a
different genus than both of its parents.
The question gives us the common
name of two types of big cats and asks us to determine the correct statement about a
cub they produce. When considering the outcome of
mating two organisms, Latin binomial names are more useful than common names. So let’s start by looking at the
binomial names for these two big cats. The binomial name for a tiger is
Panthera tigris, and the binomial name for a lion is
Panthera leo. The first word in a Latin binomial
name tells us an organism’s genus, and the second word tells us its species. We can see that tigers and lions
belong to the same genus, Panthera, but are different species.
A species is defined as a group of
organisms with similar characteristics that can breed with each other to produce
fertile offspring. For example, two dragonflies of the
same species can breed with each other to produce offspring. And this offspring will be fertile,
meaning that it can breed with members of the same species to produce its own
offspring. On the other hand, two dragonflies
of different species may be able to breed with each other to produce offspring. But this offspring would not be
fertile, meaning that even if it were to breed with other dragonflies, it would not
be able to produce its own offspring. We established earlier that tigers
and lions are different species, so a cub that they produce is unlikely to be
fertile.
Now let’s return to our answer
choices to determine the correct one. “The cub will not survive longer
than four to five years.” The offspring of a tiger and a lion
is called a liger. Ligers have been known to live into
their twenties, but we can’t make any definitive statements about the cub’s
lifespan, so this statement is incorrect. “The cub will be able to reproduce
successfully with both lions and tigers.” We know that the liger cub is
unlikely to bear fertile offspring. So it won’t be able to reproduce
successfully with lions or tigers. So this statement is also
incorrect.
“The cub is likely to be sterile
and unable to have offspring of its own.” Since the liger cub is the
offspring of two different species, this statement is correct. “The cub will be classified in a
different genus than both of its parents.” Tigers and lions belong to the same
genus, Panthera. So their offspring are hybrid
members of this genus as well. This statement is incorrect. Therefore, the correct answer is
the cub will be sterile and unable to have offspring of its own.
