No, you cannot block with a creature that has summoning sickness in Magic: The Gathering.
In Magic: The Gathering, a creature with summoning sickness cannot attack or use abilities that require tapping until its controller's next turn. However, it can still block if it has been under your control since the beginning of your turn. Therefore, while summoning sickness restricts a creature's offensive capabilities, it does not prevent it from defending against attacking creatures.
Defending creatures deal damage to an attacking creature's toughness when they block equal to their power. It's called 'blocking', not 'attacking back'. Summoning sickness has no affect on blocking. Summoning sickness is the inability of a creature to use tap (tap symbol) abilities or attack until the next turn of the owner who summoned it.
No, a creature with summoning sickness cannot block an opponent's creature.
No, creatures with summoning sickness cannot block other creatures.
In Magic: The Gathering, you can block one creature with each of your creatures that are able to block.
Yes, summoning sickness can prevent a creature from attacking or using its abilities on the turn it enters the battlefield.
No, you cannot block with a planeswalker in Magic: The Gathering. They are not creatures and cannot be used to block attacking creatures.
Yes, in Magic: The Gathering, you tap your creatures to block attacking creatures during combat.
No, in Magic: The Gathering, you can only block one creature with one creature.
In a game of Magic: The Gathering, multiple creatures can block a single creature.
No, in Magic: The Gathering, each creature can only block one attacker at a time.
Yes, in Magic: The Gathering, you can block multiple creatures with one of your creatures during the combat phase.