Answer:a) a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates.
Explanation:
An ancestor - An earlier type of a species at any distant time — a progenitor.
A tetrapod is any vertebrate with four limbs. It includes any vertebrate (such as birds or snakes) that have evolved from early tetrapods — especially all members of the superclass Tetrapoda.
The presence of bones that support the appendages in Lobe – fin fish were found to be similar to the categorical skeletal supports found in the limbs of sample tetrapods. The sub class crossopterygii includes the Lobe – fin fish, which is seen as one of the recent common ancestor of living tetrapod today.
3: Geothermal energy
4: An earthquake is the result of a sudden release of stored energy in the Earth's crust that creates seismic waves. ... An earthquake is caused by tectonic plates getting stuck and putting a strain on the ground. ... When the failure at the fault plane results in a violent displacement
5: c
6: D
Answer:
The correct answer is single,double and triple covalent bonds .
Explanation:
A carbon atom can form a single bond with another carbon atom example ethane.
A carbon atom can form a double bond with another carbon atom example ethylene
A carbon atom can form a triple bond with another carbon atom example acetylene.
But during the formation of Carbon carbon single bond or double bond or triple bond the valency of carbon atom that is 4 is always maintained.
As you can see in the picture presented below, the three classes of water have distinctive traits.
Pure substances contain only one element, they are not mixtures of different things.
The homogeneous mixtures have multiple elements, but they are so well blended together that you can't easily observe or separate them.
In heterogeneous mixtures, we can easily differentiate between different elements of the mixture.
An example of biodiversity is a greater variety of genes and species
