16 POINTS

Biology

2 answers:

katen-ka-za [31]3 years ago

8 0

Answer: The correct answer is-

C.They replaced carbon dioxide with oxygen in the atmosphere.

Cyanobacteria ( also known as blue green algae) is a large phylum of bacteria that is capable of synthesizing its own food using carbon dioxide and water in the presence of sunlight ( photosynthesis).

They contain a green pigment called chlorophyll that absorbs energy from sunlight and helps in the formation of food ( glucose). They release oxygen as a byproduct in the atmosphere.

As these organisms utilize carbon dioxide ( that is present in the atmosphere) to give oxygen in return, therefore, they affected early atmosphere of Earth by replacing carbon dioxide with oxygen.

Thus, option C) is the right answer.

STatiana [176]3 years ago

5 0

The correct answer is option C, They replaced carbon dioxide with oxygen in the atmosphere.

Reason -

Cyanobacteria are aquatic organisms that are capable to phosynthesise and produce their own food. They are unicellular bacteria found , some 3.5 billion years ago. They produced the oxygen during the Archaean and Proterozoic Eras however before that the atmosphere has an unstable chemical composition which do not support life. They also led to the origin of plants which further added to the production of oxygen in the atmosphere.

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Each of the four pedigrees that follow represents a human family within which a genetic disease is segregating. Affected individ

Ne4ueva [31]

Answer:

The following four traits are -:

Pedigree 1 - A recessive trait (autosomal recessive) is expressed by pedigree 1.
Pedigree 2- Recessive inheritance is defined by Pedigree 2.
Pedigree 3 - The inheritance of the dominant trait (autosomal dominant) is illustrated by Pedigree 3.
Pedigree 4- An X-like dominant trait is expressed by Pedigree 4.

Explanation:

Explaination of each pedigree chart-

Pedigree 1 demonstrates the recessive trait since their children have been affected by two unaffected individuals. If the characteristics were X-linked, in order to have an affected daughter, I-1 would have to be affected. $X^A$ In this, both parents are autosomal recessive trait carriers, so the child will be affected by a 1/4 (aa)
Recessive inheritance is defined by Pedigree 2. This is X-related inheritance as autosomal recessive inheritance has already been accounted for in part 1. This inference is confirmed by evidence showing that the father (I-1) is unaffected and that only the sons exhibit the characteristic in generation II, suggesting that the mother must be the carrier. The individual I-2 is a carrier for this X-linked trait. A typical Xa chromosome is attached to the unaffected father (I-1), so the chance of carrier II-5 is 1/2. Probability of an affected son = 1/2 (probability II-5 is a carrier) x 1/2 (probability II -5 contributes ( $X^A$ ) x 1/2 (probability of Y from father II-6) = 1/8. An affected daughter's likelihood is 0 because a typical $X^A$ must be contributed by II-6.
The inheritance of the dominant trait is demonstrated by Pedigree 3 because affected children still have affected parents (remember that all four diseases are rare). The trait must be autosomal dominant because it is passed down to the son by the affected father. There is a 1/2 risk that the heterozygous mother (II-5) would pass on mutant alleles to a child of either sex for an autosomal dominant feature.
Pedigree 4 is an X-linked dominant function characterized by the transmission to all of his daughters from the affected father but none of his son. On the mutant X chromosome, the father (I-1) passes on to all his daughters and none of his sons. As seen by his normal phenotype, II-6 therefore does not bear the mutation. An affected child's likelihood is 0.