STAAR Biology

1.A cheetah's leg-muscle cells are packed with an organelle that releases usable energy from food molecules. Which organelle is that?

2.A maple leaf cell captures light and builds sugar. Which organelle carries out that work?

3.A biologist stains a human skin cell and finds the chromosomes inside one membrane-bound compartment. What is that compartment?

4.A pancreas cell is building an enzyme. Enzymes are proteins. Which structure joins amino acids to make that protein?

5.Proteins that will leave a cell are sorted and packed into small membrane sacs. Which organelle does that sorting and packing?

6.A white blood cell has taken in a worn-out mitochondrion. Which organelle contains enzymes that can digest that mitochondrion?

7.A lettuce leaf is crisp when its cells hold plenty of water and limp when they lose water. Which structure in each leaf cell stores most of that water?

8.Oxygen can enter a human liver cell, but many large proteins in the blood do not pour through the cell's boundary. The cell has no rigid outer wall. What is that boundary?

9.A carrot root cell keeps a rigid, boxy shape. A layer outside the cell membrane supplies that support and is made mainly of cellulose. What is the layer?

10.A drop of food dye is placed in a still glass of water. The color spreads until the water is an even pale blue. Nobody stirs the glass. What moved the dye?

11.Which sentence uses the word osmosis correctly?

12.A plant cell is placed in pure water. Water crosses the membrane into the cell, and the central vacuole swells. Why did water enter?

13.A red blood cell is placed in a very salty solution. Water leaves, and the cell shrivels. What is true of the solution outside the cell?

14.Animal cells are kept in a solution with the same water concentration as their cytoplasm. The cells do not swell or shrink. What is happening to the water?

15.A cell from yogurt has a cell membrane, ribosomes, and DNA loose in the cytoplasm. It has no nucleus. How is it classified?

16.A cell scraped from the inside of a cheek has a nucleus and mitochondria. Which classification fits?

17.Which structure is present in both a bacterium and a human liver cell?

18.A student compares a spinach leaf cell with a human muscle cell. Which structure is in the leaf cell and missing from the muscle cell?

19.During photosynthesis, which set does a green plant take in and use?

20.What are the two main products of photosynthesis?

21.In a eukaryotic plant cell, where do the reactions of photosynthesis take place?

22.A cell runs aerobic cellular respiration to release usable energy. Which materials does it use?

23.Aerobic cellular respiration of glucose releases usable energy. What else is produced?

24.In a eukaryotic cell, which organelle makes most of the ATP during aerobic respiration?

25.A lighted tank holds fish and living water plants. Which gas link between the two organisms is correct?

26.A cell builds a protein that will be secreted. Ribosomes on a folded membrane system make that protein and pass it into the folds. What is the membrane system?

27.A scrape on a knee heals as new skin cells fill the gap. Those new cells have the same chromosome set as the skin cells already there. Which process made them?

28.In one animal species, body cells have 40 chromosomes. One body cell divides by mitosis. How many chromosomes does each resulting cell have?

29.Mitosis finishes in a body cell. How many cells result, and how do their genes compare with the parent cell?

30.Which process produces sperm cells and egg cells?

31.Human body cells have 46 chromosomes. How many chromosomes are in a human egg produced by meiosis?

32.A human sperm carries 23 chromosomes, and a human egg carries 23 chromosomes. They join. How many chromosomes does the zygote have?

33.In human sperm formation, meiosis starts in one cell that has 46 chromosomes. What is produced?

34.If human sperm and eggs each kept 46 chromosomes, what problem would fertilization cause in the next generation?

35.A bean root grows longer. The new root cells have the same chromosome number as the cells they came from. Which division is adding those cells?

36.During meiosis, a chromosome exchanges a segment with its homologous partner. What can that exchange do?

37.A liver cell and a sperm cell come from the same man. Which comparison is correct?

38.A broken bone is repaired by new bone cells that have a full chromosome set. Why is meiosis the wrong division for that repair?

39.On one strand of DNA, a base is adenine. Which base pairs with it on the opposite strand?

40.A scientist finds cytosine on one strand of DNA. Which base is paired with it?

41.One strand of DNA has the bases A T C G, in that order. What is the complementary DNA strand?

42.A short DNA strand reads G G A T. Which base sequence pairs with it in the double helix?

43.A pea plant has the genotype Tt. The allele T is dominant, and the plant is tall. Which statement names those facts correctly?

44.In a flower, R is completely dominant for red petals and r is white petals. One plant is RR and another is Rr. Both have red petals. What do they share?

45.A mouse has the genotype aa for one gene. What kind of genotype is aa?

46.A plant's genotype for seed color is Gg. What does Gg tell you?

47.In peas, T is completely dominant for tall stems and t is short stems. Which genotype produces short stems?

48.A recessive allele n causes a pale coat only in an nn animal. A fox is Nn and has a dark coat. Why is the coat dark?

49.In garden peas, T is tall and t is short. A Tt plant is crossed with another Tt plant. What genotype ratio is expected?

50.A Tt pea plant is crossed with a Tt pea plant. What fraction of the offspring are expected to be heterozygous?

51.T is completely dominant for tall pea stems, and t is short. Two Tt plants are crossed. What phenotype ratio is expected?

52.A pea plant with genotype TT is crossed with a pea plant with genotype tt. What genotypes are expected in the offspring?

53.T is completely dominant and means tall, and t means short. A TT plant is crossed with a tt plant. What phenotypes are expected?

54.In a moth, B is a dominant allele for dark wings and b is light wings. A Bb moth is crossed with a bb moth. What genotype ratio is expected?

55.B is dominant for dark moth wings, and b is light wings. A Bb moth is crossed with a bb moth. What fraction of the offspring are expected to have light wings?

56.In a flower, A is a dominant allele for spotted petals and a is solid petals. An AA plant is crossed with an Aa plant. What fraction of the offspring are expected to be aa?

57.A clotting gene sits on the X chromosome and has no copy on Y. H is dominant and gives normal clotting. h is recessive and causes a clotting disorder. A woman XH Xh has children with a man XH Y. What fraction of all the children are expected to be sons with the disorder?

58.A man has the genotype Xh Y for an X-linked clotting gene. The allele h is recessive, yet he has the clotting disorder. Why does that single allele show?

59.A woman XH Xh and a man XH Y have daughters. H is dominant normal clotting, and the gene is X-linked with no allele on Y. What is expected among the daughters?

60.A man with an X-linked clotting disorder has genotype Xh Y. He has children with a woman XH XH, who is not a carrier. H is dominant. What is expected?

61.A DNA sequence in a seed changes from AAT GGC to AAT AGC. Nothing else is known yet. What is that change?

62.A mutation appears in a gene of a seedling. Which conclusion is justified?

63.One base in a gene changes, but the protein and the visible trait stay the same. Which conclusion fits?

64.A mutation changes a gene so the enzyme made from it no longer works. The cell cannot finish a reaction it needs. What does this case show?

65.In pea plants, the tall form and the short form of the stem-length gene are different versions of that gene. What is each version called?

66.Which description best fits a gene?

67.Beetles in a field vary in a heritable shell color. Birds eat more of the beetles that stand out against the soil. After many generations, most beetles match the soil. What happened?

68.A weightlifter builds larger arm muscles. The weightlifter's child is born with ordinary infant arms, not a copy of those trained muscles. What does this show?

69.A student says giraffes have long necks because each giraffe stretched upward and then gave that stretched neck to its calves. Which account matches natural selection?

70.A turtle's shell cracks in a rockslide. The crack does not change the turtle's DNA. Can natural selection make cracked shells common in the next generation?

71.A human arm, a bat wing, and a whale flipper have the same series of bone regions, even though the limbs do different jobs. What does that shared layout suggest?

72.When are two structures in different species called homologous?

73.A bee wing and a sparrow wing are both used for flight, but they are built differently and did not come from one shared flying ancestor. What kind of similarity is that?

74.A cactus stores water in its stem and has spines where many plants have broad leaves. In a desert, those inherited traits help it survive and reproduce. What are the traits called?

75.Before a drought, some shrubs already carry a heritable allele for deeper roots. Those shrubs survive and produce the next generation. The others wilt. What is this?

76.Some beetles in a population are very strong but leave no offspring. Other beetles leave many offspring that also reproduce. Which beetles have higher evolutionary fitness?

77.An individual pond snail does not switch its inherited stripe pattern during its life. Over many generations the population changes from mostly striped shells to mostly plain shells. What evolved?

78.Hawks catch snakes that cross open sand more often than snakes that stay in grass. Staying in the grass is heritable in this population. What role do the hawks play?

79.A lizard population is genetically identical for toe length, and no new toe-length mutations appear. Can natural selection change toe length in that population?

80.Whales have small pelvic bones that do not support walking. Four-legged land mammals have larger pelvic bones that support hind limbs. What is a sound conclusion?

81.Species A and species B have nearly the same sequence across many genes. Species A and species C differ at many more sites in those genes. What does that pattern support?

82.A river splits a beetle population. For a very long time the two sides do not mix. They build up different heritable traits and can no longer produce fertile offspring together. What has occurred?

83.A bacterial population already includes a few cells with a heritable trait that lets them survive a certain antibiotic. After that antibiotic is common in their surroundings, most surviving cells have the trait. What increased its share?

84.Early embryos of a fish, a chicken, and a human each form a similar set of pharyngeal arches. The adults look very different. How can that similarity be used?

85.Which job belongs to the heart in the circulatory system?

86.Which statement about blood vessels is accurate?

87.What do red blood cells do in the circulatory system?

88.What is the main gas exchange of the respiratory system?

89.Where in the lungs does oxygen move into the blood?

90.A meal is digested and absorbed. Which order of jobs is correct?

91.What is the job of the immune system?

92.What is an antibody?

93.On a hot day, a person's internal temperature stays near 37°C. Sweating increases, and evaporation cools the skin. What is this an example of?

94.After a person eats, blood glucose rises and the pancreas releases insulin. What does insulin do in this response?

95.A person inhales. What does the diaphragm do?

96.Body temperature rises during a race. Sweating then increases heat loss, and the temperature comes back down. What kind of control is that?

97.In an energy pyramid for a grassland, which level is at the base and holds the most available energy?

98.About how much of the energy at one level of an energy pyramid is stored in the bodies at the next level, and why is the share so small?

99.A meadow can support about 200 rabbits over the long run with the food, water, and shelter available. What is that number called?

100.That meadow enters a long drought. Food and water decrease, and the rabbit population falls from near 200 toward a lower number. What changed?

101.A bumblebee lives in a meadow, collects nectar, pollinates flowers, and nests in the ground. The meadow is its habitat. What is its niche?

102.Two bird species feed on the same beach. One probes the mud for worms. The other catches small fish in shallow water. They also nest in different spots. What does this show?

103.A lava flow cools to bare rock. No soil is present. Lichens appear first, and soil slowly forms. What kind of community change is this?

104.A fire burns a pine woods, but the soil remains and many roots and seeds survive. Grasses and shrubs return before a new stand of pines. What is this?

105.A growing oak tree adds mass that includes carbon in its wood. Where did that carbon come from, and by what process?

106.A deer eats leaves and later breathes out carbon dioxide. Which process returns that carbon to the air?

107.A rabbit eats clover. Which statement correctly tracks carbon?

108.A dead rabbit decays. Bacteria and fungi break down its body. How can that return carbon to the air?