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dusya [7]
3 years ago
9

1. When did stromatolites appear on Earth? Archean Hadean Mesozoic Proterozoic

Biology
1 answer:
professor190 [17]3 years ago
7 0

Answer:

Proterozoic

Explanation:

Stromatolites appear on Earth in the end of Proterozoic era because Proterozoic extended from 2500 million years to 542 million years. The stromatolites were present on earth about 542 million years ago. The stromatolites present in large number on the sea shores around the world and are considered as the Earth's first visible life form which can be seen through naked eye. These stromatolites were the first known organisms in which photosynthesis occurs and produce free oxygen..

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Describe in detail how are crayfish hunts and eats its food.
MakcuM [25]

Answer:

Crayfish use their large pincers to capture common prey items, such as worms, leaches, snails. Additionally, crayfish occasionally capture large prey, such as frogs, fish, salamanders and tadpoles. Frog eggs and insects are important foods for the juveniles of many species.

8 0
3 years ago
2. Identify How did Darwin explain the similarities among finches in the Galápagos
Studentka2010 [4]

Answer:

He said they all came from one ancestral species.

Explanation:

They all came from the same species but mutations due to their differing habitats changed them all slightly.

7 0
3 years ago
In order for chemical digestion to occur, what has to be mixed with the food?
siniylev [52]
Well in order for chemical digestion to occur period, a enzyme is needed.

In the mouth this enzyme is amylase
8 0
3 years ago
Summarize the nitrogen cycle and it’s importance of proteins and DNA
iren2701 [21]

Answer:

Nitrogen cycle works through various stages like, nitrogen fixation, nitrification, assimilation, ammonification, denitrification etc. It is a building block for protein and DNA

Explanation:

Nitrogen is an element abundantly found in the atmosphere, also its building block for proteins as well as nucleic acid i.e. DNA formation. In nitrogen cycle , the nitrogen is being prepared from inert nitrogen.  The nitrogen cycle has several processes like nitrogen fixation, in this the inert nitrogen is being converted to organic nitrogen with the help of certain micro-organism.

Nitrification, plants cannot absorb directly nitrogen so bacteria help the plants to convert the nitrogen into ammonia form in this stage. Assimilation, another stage in which plants starts absorbing various forms of nitrogen from the soil.i.e. nitrate, nitrite and ammonium. Ammonification, here plants and animals have nitrogen in there body after death various microbes help in decomposition in this stage. Denitrification, in this stage the return back of nitrogen takes place.

4 0
3 years ago
What is the expected phenotypic ratio for a cross between two individuals that are heterozygous for a given trait? Use one of Me
svetlana [45]

The expected phenotypic ratio for a cross between two individuals that are heterozygous for a given trait is 3:1.

<h3>What is Phenotype?</h3>

This is referred to the physical characteristics of an organism such as the size, shape etc.

When two heterozygous traits are crossed:

Rr ×  Rr ⇒ RR Rr Rr rr

The ratio is therefore 3:1 of the dominant to recessive phenotype.

Read more about Phenotype here brainly.com/question/22117

#SPJ1

8 0
2 years ago
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