26. The four phases of mitosis (in order) are ____________, _______________, ______________ and __________________. List a general description of what happens in each phase.
27. ________________ is the genetic material that contains information for making proteins.
28. Scientists James Watson and Francis Crick discovered that DNA is in the shape of a ________________ ______________. Another description is a twisted ladder.
29. Before mitosis occurs DNA forms into chromosomes. In a human there are ______ chromosomes or ______ pairs.
30. A _________________ is a picture of chromosomes. Doctors or scientist arrange the chromosomes into like pairs. The last pair is the sex chromosomes. This picture can show the sex of the person. Male’s last pair look like ______ and female’s last pair look like _______.
31. _________________ is a genetic disorder where the individual has an extra chromosome that is similar to the chromosomes in the 21st pair. The individual is mentally retarded and sterile (unable to reproduce).
32. Gregor Mendel discovered the laws of dominance and recessiveness. A ______________gene will “mask over” or “over shadow” the outcome of a _______________ gene.
33. ______________ dominance is a phenomenon where the combination of a dominant and a recessive gene forms an intermediate outcome. For example, Red color in some flowers is dominant and white color is recessive. If a flower has two red genes then the flower is red, if it has two white genes then the flower is white, but if the flower has one red and one white, the offspring is pink.
34. _________________is a term used to express the actual DNA make up of the gene. In the study of genetics we use letters to represent this. Capital letters represent dominant genes and lower case letters represent recessive genes. An example could be TT, Tt or tt.
35. ____________________ is a term used to express the appearance the gene causes. Tallness in pea plants is an example. Hair color is another example.
36. _________________is a term used to describe two genes (sometimes called alleles) that are alike. For example in some tall pea plants it would be “TT” or short pea plants “tt”. Notice the letters are the same!
37. _________________ is a term used to describe two genes that are different. For example “Tt” in tall pea plants. Notice the letters are different. Because there is one dominant gene (“T”) the plant will be tall because the dominant gene “overshadows” the “t” or the recessive gene.
38. Choose and animal and give an example of it habitat and niche.
39. Compare and contrast the tundra and the taiga biomes
40. Describe the climate of the desert.
41. Compare and contrast mitosis and meiosis.
42. Explain the importance of biodiversity.
43. What is the difference between sexual and asexual reproduction?
44. How can the process of natural selection change a population?
45. Compare and contrast primary and secondary succession?
46. How do cells become cancerous?
47. List some ways to help protect our environment.
48. What is a mutation?
49. Compare and contrast animal and plant cells.
50. Please make sure you look over lesson 4.01 and 4.02 and can do punnett squares.
Here is an example of a typical punnett square problem. If you cross pollinate two plants that are heterozygous for purple flowers. (Purple is dominant to white) What are the possible outcomes for the offspring?
“P” for purple and “p” for white
Heterozygous Purple Flower would be Pp
Look at the possible outcomes in the boxes.
PP, Pp, Pp, and pp
PP looks purple because it has two purple genes
Pp looks purple because it has at least one purple gene
pp looks white because it has no dominant purple genes
PP, Pp and Pp are all purple possibilities or 75% of the time the offspring will have purple flowers.
pp is the white flower offspring. It only occurs in 1 out of 4 boxes and therefore 25% of the time the offspring will have white flowers.