Log inSign up for FREE
Library

STAAR HS Biology

Last updated 9 months ago
46 questions
Required
1

Humans have thousands of genes that combine in different ways to help create unique individuals. Where is the genetic code primarily located?

Required
1

The table shows the relationships of some organisms that live in Texas Hill Country habitat.


Based on the data in the table, which food chain depicts a correct flow of energy through the Texas Hill Country habitat?

Required
1

A large part of Texas is made up of open areas covered in grasses. Together these areas form a grassland biome. There are multiple levels of organization that help form a biome. One of these levels is a community.

Which example BEST represents a community in the grassland biome?

Required
1

The graph shows a change in a population of cacti.


Which claim is supported by the graph?

Required
1

Curly hair and the ability to taste the chemical PTC are inherited traits. Curly hair (H) is always dominant to straight hair (h). The ability to taste PTC (P) is always dominant to not being able to taste PTC (p). The alleles for straight hair and a non-taster for PTC are recessive.

If both parents are heterozygous for both traits, what would be the genotype of an offspring with straight hair and the ability to taste PTC?

Required
1

On the Edwards Plateau in Texas, shrubs grow in arid areas with relatively thin limestone soils. Although these shrublands may transform into forests, the transformation is very slow and never occurs in some places.

The image shows an arid area with shrubs and some trees growing.


Which factor MOST LIKELY slows or prevents this ecosystem's progression from shrublands into forests?

Required
1

Dogs have 39 pairs of chromosomes in their somatic cells. In which part of the cell are these chromosomes replicated during the cell cycle?

Select ONE correct answer.

Required
1

In the late 19th century, Charles Darwin and his son performed a series of experiments on young grass seedlings to observe the plants' response to sunlight. They grouped the seedlings as shown in the list:
  • They removed the tips of one group of seedlings.
  • They placed opaque caps over the tips of a second group of seedlings.
  • They placed transparent caps over the tips of a third group of seedlings.
The results of the experiment are shown in the diagram.



Based on the diagram, which statement BEST supports the results of the experiment?

Required
1

Scientists have reported that more than 95% of the factors that lead to some types of cancers are caused by random DNA-copying errors. During which phase of the cell cycle do these DNA-copying errors most likely occur?

Required
1

The diagram shows changes in blood pressure over time.


Vasodilation and vasoconstriction occur because blood \{-}

Required
1

Nitrogen is an essential component of all living things. However, atmospheric nitrogen is unavailable for organisms to use. through various processes and chemical changes, nitrogen moves through the biosphere, atmosphere, and geosphere in different forms, making it available for all organisms. Atmospheric nitrogen is deposited in the soil and surface waters primarily through precipitation. Once in the soil, microorganisms break down the nitrogen into different forms, which is then taken up by plants. Nitrogen eventually makes its way back into the atmosphere.

What would happen within the nitrogen cycle if a bactericide, a substance that kills bacteria, was added to the soil?

Required
1

A student claims that the influenza virus replicates int he air and then infects people. Which statement BEST describes the claim?

Required
1

A DNA mutation results in a protein that is the same as the initial protein synthesized before the mutation. Which statement BEST explains this outcome?

This question has two parts.

Giant salvinia is a floating fern native to Brazil introduced to Texas as an aquarium plant and is not found in large bodies of water across the state. The invasive plant may be carried to new bodies of water by fishing and recreational boats. It grows quickly, covering large areas of the water's surface. When the plant dies and decomposes, the oxygen content in the water declines.
Required
1

Part A
Which statement BEST describes how giant salvinia affects a Texas ecosystem?

Required
1

Part B
Which evidence supports the answer to Part A?

Required
1

Milk that is sold for human consumption is often pasteurized. During this process, the milk is heated to a high temperature.

Which statement describes the main benefit of this process?

Required
1

A phylogenetic tree based on similar structures is shown.


Which statement is correct based on teh phylogenetic tree?

Required
2

In animal cells, the sodium-potassium pump moves sodium and potassium ions against a concentration gradient across the cells membrane.

What type of transport is used, AND why is this type of transport necessary?

Read the question carefully. Then enter your answers in the box provided.

Required
1

Actin is a protein that helps teh cell maintain its shape and polarity. It also plays a major role in muscle contraction. A table summarizing the cellular functions of different types of proteins is shown.


Based on this information, actin is most likely -

Required
1

Cytochrome c is a protein that is found in the mitochondria of all aerobic eukaryotic cells. The gene sequence for cytochrome c has been mapped and analyzed for thousands of species. The table shows the percentage of the cytochrome c amino-acid sequence that different species have in common.


Which list is ordered from the species most closely related to the mouse to the species least closely related to the mouse?

Required
2
Scientists can use the fossil record to determine changes in an environment. What does the abrupt appearance of new organisms show?

The abrupt appearance of new organisms is evidence of __________ and __________.
Required
1

A scientist examined two populations of the grasshopper species Atractomorpha lata. The scientist found that the population raised in higher temperatures had a higher frequency of brown coloration, while the population raised in lower temperatures had a higher frequency of green coloration.

Based on this information, which biological process is affected by temperature in A. lata?

Required
2
A student is making a table to describe the processes of photosynthesis and cellular respiration. Complete the table by identifying which process causes each result shown in the table.

Move the correct answer to each box. Each answer may be used more than once.
Other Answer Choices:
Cellular respiration
Photosynthesis
Required
1

Which statement accurately compares eukaryotic cells and prokaryotic cells?

Required
1

An mRNA sequence and an mRNA codon chart are shown.


What is the amino acid sequence that will be translated from the mRNA sequence?

Required
1

Which pair of scenarios correctly identifies examples or characteristics of primary and secondary succession?

Required
2

Ecological relationships occur between two species that live close to each other. Two examples of ecological relationships are described.
  • Example 1: Bees gather nectar and pollen from flowering plants, providing food for the bees. As the bees move to different flowers, some of the pollen attached to the bees' bodies is spread and released. If the pollen falls on the flower of a plant of the same species, it may fertilize the plant and produce seeds.
  • Example 2: Orchids are flowering plants that grow on other plants. They typically grow in tall trees high in the canopy, where they can reach sunlight for photosynthesis. They get water and nutrients from rainwater runoff that carries organic material down the host plant's branches. No water or nutrients are taken from the host plant.

What is the main difference between the ecological relationships described in the two examples? Include the scientific term used to define each of the relationships.

Think about the question carefully. Then enter your answer in the box provided.

Required
1

A student observed a human cheek cell under a light microscope and made these observations:
  • The chromatin is condensed.
  • There is no visible nucleolus.
  • The spindle fibers are visible.
  • The nuclear membrane looks like it is disappearing.
Which phase of the cell cycle is this student MOST LIKELY observing?

Required
1

Cystic fibrosis is an autosomal recessive disorder in humans. What is the probability that an offspring will have cystic fibrosis if both parents are carriers of cystic fibrosis?

Required
1

The diagram represents the movement of three different substances across a cell membrane.


Moving which of these substances across the cell membrane requires energy from ATP?

Required
1

Which table correctly describes the lytic and lysogenic cycles?

This question has two parts.

By sending signals that stimulate the release of hormones, the human brain controls the cyle of digestion, including the processes of nutrient absorption. The brain initiates the release of these hormones at certain times of the day, based on the body's 24-hour circadian clock. These hormones stimulate nutrient absorption.
Required
1

Part A
Based on this information, which two body systems of MOST DIRECTLY regulating the digestive system?

Required
1

Part B
Which statement BEST supports the answer to Part A?

Required
2
Identify the components of DNA.

Move the correct answer to each box. Not all answer will be used.
Other Answer Choices:
Deoxyribose sugar
Base pair
Ribose sugar
Phosphate
Nitrogenous base
Nucelotide
Required
1

As part of a wildlife conservation program, researchers take a small population of wolves and relocate them to an island. After several generations, researchers analyze the genomes of the wolves in the population and determine that there is little genetic variation in the population.

Which evolutionary mechanism BEST explains the low level of genetic variation of these wolves?

Required
1

The bar graph shows the average beak depth (distance form the top of the beak to the bottom) of a population of finches. The data were collected in 1976 and in 1978, after a drought occurred in 1977 in the area.


Which factor BEST describes the change in this population of finches?

Required
1

Which table correctly identifies organelles found in plant cells and in animal cells?

Required
1
Giraffes (Giraffa camelopardalis) have 30 chromosomes in their somatic cells. How many chromosomes will each daughter cell have after the final step of meiosis?

Enter your answer in the box. Your answer must be a whole number.

_______
Required
1

Rennin is an enzyme that catalyzes a reaction that solidifies milk. Rennin was added to three different test tubes with milk. Each test tube was placed in a water bath for ten minutes. The data collected during the experiment are shown.


Which statement best explains the result of test tube 3?

Required
1

The oak mistletoe is a green, leafy plant that grows on trees and has white berries Mistletoe seeds are spread to other trees through the waste of birds that feed on the berries. The mistletoe seedlings grow in the tree to obtain water and nutrients.

Which answer choice correctly identifies a relationship between two of these organisms?

Required
1

Purple loosestrife is an invasive flowering plant species now found in North America. In an effort to control the purple loosestrife, biologists tested and released three beetle species to use as a biological control of the plant.


Which result is an unintended negative consequence of releasing these beetle species into the environment?

Required
1

A student athlete wants to choose a drink that will provide quick energy for track practice. Which portion of the label should provide the athlete with information about the amount of quick energy in the drink?

Select ONE correct answer.

Required
1

As unspecialized cells mature, what controls their development into specific cell types?

Required
2
Complete the sentences to describe a start codon.

Move the correct answer to each box. Not all answers will be used.

Almost every organism begins the process of protein synthesis with a ____________ nucleotide sequence. This start codon is translated to a common _______________ in all organisms.
Other Answer Choices:
amino acid
triplet
peptide
doublet
glucose
Required
1

The classification information for several organisms is shown.



Which answer choice identifies the two organisms that are most closely related and why?

Required
1

During the Industrial Revolution in England, burning coal increased the soot level in the air, and the soot darkened the tree bark. As a result, the population of dark-colored peppered moths significantly increased.

Which statement describes the MOST LIKELY reason why the population of dark-colored peppered moths increased?