Study Guide BIOLOGY GENETIC I

Central Idea 1: Living systems reflect a hierarchy of levels of organization. This is described in the following flow chart: CELLS TISSUES ORGANS ORGAN SYSTEMS INDIVIDUALS POPULATIONS

Sample Item: The diagram of a cross-section of a leaf is shown above. The different kinds of tissues making it up are labeled. What level of organization is exemplified by the leaf? A organ C cells B organ-system D organism

Central idea 2: Genetic information is housed inside the cell’s nucleus. These genes make up the chromosomes of a cell. Proteins are found in chromosomes as well, along with DNA.

Sample Item 2 The instructions needed by the cell to live, grow, and reproduce come from ___________ which is found in the ___________________. A) chloroplasts / mitochondria B) ATP / sugars C) cell membrane / cell wall D) DNA / nucleus

Central Idea 3 Sexual reproduction yields offspring that are NOT genetic clones of the parents. Fertilization involves the fusion of male and female gametes, each carrying ½ the genetic information that will be found in the zygote.

Sample Item 3 Which of the following describes the process shown in the diagram? A) This process exemplifies asexual reproduction. B) This process exemplifies sexual reproduction. C) This process diagrams differentiation of stem cells. D) This process results in the production of clones, or identical offspring.

Central Idea 4 The zygote divides repeatedly to form cells called embryonic stem cells. Through a process called ‘differentiation,’ stem cells grow and develop into specialized cells (skin cells, nerve cells, etc).

Released Item 4 The process by which multi-cellular organisms develop different types of cells such as brain and skin cells is called - A) speciation. B) differentiation. C) replication. D) duplication.

Central Idea 5 What is the difference between allele and genes? A gene codes for a specific trait [e.g. seed color]. An allele is an alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome.

Released Item 5 Which of the following statements correctly uses the terms “allele”, “genes”, and/or “trait”? A) B and b are alleles representing the same gene. B) B and b are traits representing the same alleles. C) B and b are gametes representing the same trait. D) B and b are protein fibers representing the same trait.

Central Idea # 6 Mendel’s studies focused on traits controlled by a gene represented by two alleles. One allele is dominant over the other. A ‘Punnett Square’ diagram is used to show the ‘segregation’ or separation of these alleles.

Sample Problem 6 A student set up a Punnett Square to determine the genotypes of the possible offspring from a cross between a ‘Yy’ and ‘yy’ for pod color. In which step did he make a mistake?

Central Idea 7 Chromosomes in cells occur in pairs. The total number of chromosomes in a cell [except in sex cells or gametes] is called its diploid (2n) number. Gametes carry the haploid (n) number, that is half the diploid number. Cells from a sperm or egg cell has 23 chromosomes. A diploid human cell has 46 chromosomes [23 pairs].

Sample Item 7 How many individual chromosomes must have come from each parent to produce the karyotype on the right?