1
In an ecosystem, a group of individuals of one species that live together is called?
a population.
What is the largest phylum of animal on Earth?
Arthropods
Do Female walruses have tusks?
The majority of sea birds live in which hemisphere?
southern
sea stars use what for locomotion?
thousands of tube feet.
Krill are common in which kind of water?
temperate and polar water.
Polar bears are under threat due to what?
decreasing sea ice in the Arctic as a result of global warming.
Is shorebird belong to seabirds?
Yes
The body of an arthropod is _____ and ______ symmetrical, with jointed appendages.
Segmented; bilaterally
What is included in abiotic factors?
temperature, acidity, pressure and so on.
All populations live together is called？
community.
Chordates have how many nerve cords?
1
Shrimps are found mostly in which kind of habitat?
benthic habitats.
What do sea turtles eat?
seaweeds, seagrasses, jellyfish, and other invertebrates.
What are the first vertebrates on Earth?
Fishes.
Rays and skates have how many pairs of gill slits on the ventral (underside) of their bodies?
5
Cetaceans have front__________?
flippers.
What is one of the most distinctive features of sea cucumbers?
They do not have spines and are lacking in obvious pentamerous symmetry.
About ____________ million years ago, mammals underwent a rapid diversification.
65
what will organisms do with each other?
they consume each other, they fight for space and other resources, and they provide shelter or habitat for other organisms and they even live together in symbiotic relationships.
why there are competitions in the ecosystem.
because there are limited food, resources, competitors and predators.
What are the three major groups of fishes?
Jawless fishes, Cartilaginous fishes, and bony fishes.
which act is passed in 1972, bans the hunting of all marine mammals in the U.S?
Marine Mammal Protection Act.
Why do jawless fishes feed by suction with a round muscular mouth?
Because they lack jaws.
Which kinds of animals have undergone recovery in the modern era?
humpback whales and Steller sea lions.