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Base your answers to questions 1 on the information below and on your knowledge of biology.
Female mosquitoes spread diseases when they bite humans to obtain blood. It is only the females that do the biting. Research is being conducted to alter the DNA of male mosquitoes. These altered males could then mate with normal female mosquitoes. All of the resulting female offspring would have wing defects that prevent them from flying.
One assumption from this research is that the*
A significant difference between the effects of the genetic information passed on from asexually reproducing parents to their offspring and sexually reproducing parents to their offspring is the*
Some organs in the human body are represented in the diagram below.
A sudden change in the DNA of cells developing in which organ could be passed to future generations?*
Two kittens in a litter are genetically different from each other and from their parents. These genetic differences are most directly due to*
Which diagram correctly represents a step in the normal process of human reproduction?
*
Which expression correctly represents a repro- ductive process that usually occurs in humans where 2n is equal to the number of chromo- somes in each body cell?*
Some variation must be present in a population in order for natural selection to take place. These variations arise from mutations in the DNA and*
A human skin cell contains 46 chromosomes. A frog sperm cell contains 12 chromosomes. Which pair of numbers shows the chromosome number of a normal gamete from each of these species?*
The hair colors of the members of a family are listed below.
mother – brown hair
father – blond hair
older son – brown hair
younger son – blond hair
The hair colors of the sons are most likely a direct result of*
The diagrams below represent two reproductive processes used by different organisms.
When compared to organisms that utilize process A, organisms that utilize process B would most likely produce offspring with*
A female giraffe has 62 chromosomes in each of her skin cells.
How many chromosomes will be in the skin cells of her offspring?*
All organisms need to reproduce for the continuation of their species. Discuss the process of reproduction in humans. In your answer, be sure to:
• identify one hormone present in a female that is involved in regulating the reproductive cycle [1]
• state one way the nucleus of a sex cell is different from the nucleus of a body cell [1]
• state how the normal chromosome number for humans is maintained from one generation to the next [1]
• identify one action by the mother that can influence the development of the embryo and state a result of that influence [1]*
Base your answers to questions 16 on the passage below and on your knowledge of biology. Biologists have been studying the genes present in newborn twins.
Twins Don’t Share Everything
…Chemicals called epigenetic markers can be attached to those [inherited] genes, like flags or balloons hanging off the sides of the DNA ladder. These don’t just change the look of the genes. Like pieces of tape stuck over a light switch, these markers can force a gene to remain turned on or off. The type of marker scientists studied in the twins generally sticks the switch in the off position so that some proteins don’t get made. And that means the proteins’ jobs won’t get done.
Every time a cell divides, new epigenetic markers may form. Foods, pollutants, and stress may all contribute to the development of new markers. So throughout our lives we tend to accumulate more and more. But a few are there from the day we’re born.
…His [Jeffrey Craig’s] team found that newborn twins have markers attached to different genes from the very start. It’s true in identical twins, which come from the same fertilized egg. It’s also true in fraternal twins, which come from different fertilized eggs. However, fraternal twins had more such differences than identical twins did.
Source: Science News for Students; July 31, 2012
Explain why the genetic material in an offspring produced by sexual reproduction contains genetic material that is not identical to the genetic material of either parent. [1]*
Base your answers to questions 17 on the information below and on your knowledge of biology.
The testes of a human male produce gametes. The process that produces these gametes differs from the process that produces new skin cells in the same individual.
How does the genetic makeup of the skin cells differ from the genetic makeup of the gametes? [1]*
Base your answers to questions 18 on the illustration and passage below and on your knowledge of biology.
A few breeds of cat have no tails. Manx cats have extremely short tails and may even appear to have no tail at all. Manx cats were first discovered several hundred years ago.
Scientists have determined that a certain mutation in a group of genes (called T-box genes) interferes with the development of the spine in the cat embryo. Mutations in these T-box genes can cause abnormalities in the number, shape, and/or size of bones in the spines of Manx cats, which results in smaller spines and shorter tails.
If a Manx cat inherits one copy of the mutated T-box gene and one copy of the normal gene, it will have a very short tail or no tail at all.
If the cat embryo inherits two copies of these mutated genes, it will stop developing and die. Therefore, all surviving Manx cats have only one copy of the mutated gene.
Two Manx cats have several litters of offspring. Explain how the genes that the kittens inherit determine whether they will have a normal tail or a short tail. [1]*
