8th Grade Our Genes, Ourselves/Evolution

Transcription

1 Read and answer each question carefully. 1) Which of the following is an example of asexual reproduction? A) Flowers from two different plants are mated to produce a seed. B) A worm is split in two: each half grows back into a complete worm. C) A fish releases sperm which unites with an egg of another fish. D) A gray cat is the offspring of a black cat and a white cat. 2) The offspring of asexual reproduction is identical to the parent except in the case of A) a genetic mutation. B) a clone. C) fertilization. D) pedigrees. 3) The offspring of sexual reproduction A) receive half of its genetic material from each parent. B) receive all of its genetic material from one parent. C) develop genetic material independently. D) receive genetic material from their environment. 1

2 Use the following data table to answer questions 4 and 5. 4) Which of the following is a possible explanation for why there were no white flowers in the second generation of pea plants? A) Red is the dominant trait when combined with white. B) White flowers will only result if both parents have white flowers. C) Red and white colored flowers will mix to create pink flowers. D) There were not enough nutrients in the soil to produce white flowers. 5) What trait would the green seed color be considered? A) dominant B) co-dominant C) recessive D) incomplete dominance 2

3 6) An inherited trait can be determined by all of the following EXCEPT A) personal choice B) a single gene C) multiple genes D) the environment 7) Two parents are both carriers of a genetic trait that is based on only one gene. (indicated by "a" on the Punnett square) The chances that their offspring will show this trait (be homozygous recessive "aa") are A) 100% B) 50% C) 0% D) 25% 3

4 8) The trait for tongue rolling is represented by "R" or "r". In the Punnett square shown, the empty square should be filled in as A) Rr B) RRrr C) RR D) rr 9) The dominant condition (tongue rolling) of this characteristic would appear in the following gene combinations A) Rr and rr B) RR, Rr, and rr C) RR and rr D) RR and Rr 4

5 10) If two parents are heterozygous dominant for the tongue rolling trait (Rr), what is the ratio of dominant to recessive for this trait in their offspring? A) 4:0 B) 1:3 C) 2:2 D) 3:1 11) Which of the following statements is NOT a description of the role of genes in heredity? A) Mutations in DNA patterns result in variations of genes and traits. B) No two genes are alike and account for the many differences between organisms. C) Parents can select the most favorable genes to be passed on to their offspring. D) Genes contain the units of information that determine traits passed on to offspring. 12) What is the best method for determining that a group of individuals is genetically related to each other? A) reviewing family histories B) studying human pedigrees C) comparing facial features D) analyzing their DNA 13) The advantages and disadvantages of a procedure, such as cloning, are called A) trade offs. B) ethics. C) personal values. D) manipulation. 5

6 Questions 14,15,16 refer to the following paragraph: A population of birds eats green and brown moths that live in a pine forest. The brown moths are usually seen more quickly by the birds and eaten sooner. 14) The fact that the brown moths are easier to see and are more likely to be eaten is an example of A) inheritance. B) mutation. C) natural selection. D) genetic variation. 15) Based on the paragraph above, what is the most likely reason that there are more green moths than brown moths? A) Their food supply is more plentiful than the brown moths. B) Their coloring makes them better adapted than the brown moths. C) They are more aggressive than brown moths. D) They fly faster than the brown moths. 16) Imagine that increased pollution caused the pine trees in the forest to be heavily covered with brown particles. What is most likely to happen? A) There would be no change in either population. B) Birds will eat fewer brown moths. C) Birds will eat more brown moths. D) The green moths would choose to have more brown offspring. 6

7 17) Which of the following scientists proposed the theory of natural selection? A) Charles Darwin B) Alfred Russel Wallace C) Isaac Newton D) Jean-Baptiste Lamarck 18) A man lifts weights and exercises until he is very muscular. He works out with the hope that his children will be born both muscular and strong. A problem with this idea is that A) these characteristics may make the offspring less likely to survive. B) the mother determines the muscular strength of the offspring. C) not all offspring want these new characteristics. D) characteristics acquired during one's lifetime cannot be passed on to offspring. 19) Which situation could lead to the extinction of the polar bear? A) The warming of Earth causes the ice at the poles to melt. B) The salinity of the sea water in their habitat stays the same. C) Their main food source continues to reproduce at the same rate. D) The number of tourists visiting their habitat is limited. 20) Which if the following statements is FALSE? A) Species that are endangered have a high risk of becoming extinct. B) Millions of species of organisms live on earth. C) Most evolutionary change has occurred over the last few hundreds years. D) Many species that have lived on earth are now extinct. 7

8 21) Which of the following would scientists use to determine how organisms have evolved from common ancestors? A) the number of fossil discoveries B) DNA and skeletal features C) environment and habitat D) the number of different species 22) A possible cause of the cheetah becoming an endangered species is A) their habitat has changed. B) they have few predators. C) their reproduction rate increases. D) they capture prey easily. 23) In the Galapagos Islands, Darwin collected samples of many different species of finches (a small bird). All the finches were similar but the species varied in color, size and beak shape. Darwin believed A) the shape of a finch's beak was related to the food it ate. B) there was no relationship between the different species of finches. C) over time, all the beaks would eventually be the same size and shape. D) the shape of a finch's beak changed as the bird got older. 8

9 24) This graph illustrates Baptiste Lamarck's theory that A) Over time, more giraffes were born with longer necks than shorter necks. The giraffes with the longer necks survived and passed this trait on to their offspring. B) Over time, the long neck giraffe population decided it liked to eat the leaves on the top of the Acacia trees. This trait was passed on to their offspring. C) Over time, more giraffes were born with shorter necks than longer necks. The giraffes with the shorter necks survived and passed this trait on to their offspring. D) Over time, the number of predators of short neck giraffes decreased. 25) A species of lake fish has a dark-colored back and a light-colored belly. The dark back blends in with the dark bottom of a pond when seen from above. The light belly blends in with the light sky when seen from below. Which of the following is the best inference? A) This fish is a mutation. It will attract predators. B) Over time all of the species will become dark colored. C) This fish adapted to its environment. D) The coloration has no effect on its survival. 9

10 26) Some organisms have adapted behavioral cycles that increase their chance of survival. Which is an example of changing behaviors? A) a bear hibernating when food is scarce B) bacteria becoming resistant to an antibiotic C) a dandelion seed blowing in the wind D) a walking stick (insect) changing its appearance from its predator 10