2021 STAAR Biology Practice #3

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Answer explanation

 The nerves in the integumentary system (skin) sense the irritation and send the signal to the brain. The brain then sends impulses through the nervous system to scratch the itch. 

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NGSS.MS-LS1-3

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Answer explanation

Cyclins control the progression through the cell cycle. If cyclins do not degrade, then cells will continue to go through the cell cycle, resulting in the formation of a tumor (uncontrolled cell growth). 

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NGSS.HS-LS1-4

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Answer explanation

This type of mutation is a substitution because the T nucleotide in the GTA DNA triplet was replaced with a G nucleotide in the mutated DNA triplet. 

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NGSS.HS-LS3-2

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Answer explanation

The resistant individuals that survive the spraying of pesticide are able to reproduce. This resistance is likely due to a genetic variation that has been inherited from their parents. As the pesticide-resistant insects reproduce, the genetic variant that makes them resistant to the pesticide will become more prevalent in the population. 

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NGSS.HS-LS4-2

NGSS.HS-LS4-4

NGSS.HS-LS4-5

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Answer explanation

The main function of the wings of the Gentoo penguin and the legs of the common ostrich is for locomotion, which allows the birds to escape from predators. 

Tags

NGSS.HS-LS4-2

NGSS.HS-LS4-4

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Answer explanation

All living things are made of cells, which contain DNA made of the nucleotides adenine, thymine, guanine, and cytosine. 

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NGSS.HS-LS1-1

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Answer explanation

Using the general 10% law, which states 90% of the energy is lost at each trophic level (grass being at 100%), the hognose snakes would receive 0.1% of the energy produced by the grass, and at most, the owl could receive 1% of the energy produced by the grass. 

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NGSS.MS-LS2-3

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Answer explanation

The process of the cell cycle is how living organisms produce more cells, which allow the organisms to grow, develop, and reproduce. 

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NGSS.HS-LS1-4

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Answer explanation

Light energy is captured by the pigments in leaves during photosynthesis. The light energy is converted into chemical energy in the bonds of glucose, which is made during photosynthesis. Glucose is then used during cellular respiration to make another kind of chemical energy, ATP. 

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NGSS.HS-LS1-5

NGSS.HS-LS1-7

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Answer explanation

Overfishing decreases the stability of the ecosystem by disrupting the food chains of other organisms within the ecosystem. This causes an imbalance in predator-prey relationships, resulting in either a decrease in certain organisms or an increase in others. 

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NGSS.HS-LS2-6

NGSS.HS-LS4-5