RNA has great capability as a genetic molecule; it once had to carry on hereditary processes on its own. It now seems certain that RNA was the first molecule of heredity, so it evolved all the essential methods for storing and expressing genetic information before DNA came onto the scene.

6 0

2 years ago

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Polar bears and grizzly bears share a common ancestor (similar to you and your cousin sharing a grandparent); Describe some sele

Natali5045456 [20]

Lasting genetic similarities make the two bears biological sister species, more closely related to one another than to any others. ... But Ursus maritimus has also evolved to match its polar environment, growing a longer snout than brown bears' and larger, paddle-like paws, both of which aid polar bears in hunting seals.

7 0

2 years ago

Hunt and her team designed an experiment to test her hypothesis about the effect of BPA on mice. They administered daily doses o

katovenus [111]

Answer and Explanation: The figure below shows the doses of BPA administered to the female mice over time.

An experiment is used to determine cause and effect among variables. When the research is for the impact of a treatment, researchers randomly separate individuals in two groups:

Control Group doesn't receive any treament or a placebo or a treatment whose outcome is already known;
Treatment Group receives the treatment;

For the female mice on the image below, in the First Group is not injected any dosage of BPA, so they are the control group, while the others are treatment group.

The variables in a experiment are classified as independents or dependents:

Independent Variable is the cause;
Dependent Variable is the effect;

For the BPA research, since it is the effect of BPA over time on the mice's cells it is being investigated, dosage of BPA is the independent variable and time is the dependent variable.

6 0

2 years ago

Which of these is an agent of abrasion?

patriot [66]

Answer:

A. Rock pieces

Explanation:

Abrasion is the breaking down and wearing away of rock material by the mechanical action of other rocks. Three agents of physical weathering that can cause abrasion are moving water, wind and gravity. None of those are agents of abrasion. But Rock pieces are a result of abrasion.

3 0

3 years ago