Answer:
A purebred organism can either be TT or tt.
It is possible for two genetically different plants to have the same phenotype.
Explanation:
Homozygous.
You can tell in future that if both letters are either lowercase or upper case (e.g. TT or tt) the answer is always HOMOzygous. If the letters are different cases (e.g. Tt or tT) the answer is always HETROzygous. This is because 'homo' means 'same' and 'hetero' means 'different'.
Answer:
Every winter, Arctic sea ice grows around the pole, its frozen tendrils threading along northern coasts. Right now sea ice has just passed its peak coverage for the year, and will begin to shrink with the coming of spring. It’s a crucial time for polar bears, whose food supply is inextricably linked to sea ice.
And in recent decades, sea ice has been shrinking faster than ever. According to the National Snow and Ice Data Center, 2019 has the seventh-lowest sea ice cover in the Arctic since they began collecting satellite data 40 years ago.
This year “doesn't break any records, but it's the trend that matters,” says University of Alberta polar bear scientist Andrew Derocher. “The downward trend in Arctic sea ice across all months is the concern,” he says, and “now we wait to see what spring conditions bring.” (Read more about global warming’s link to polar bears.)
A cold spring allows ice to linger, giving polar bears easier access to one of their favorite foods: seals. A warm spring cuts short the availability of their food super-highway....
