Monohybrid & Dihybrid Unit 2 Biology Test Answers

___ 20 Monohybrid & Dihybrid Quiz 1. In dogs, wire hair (A) is dominant to smooth hair ((a). a). A homozygous wire hair haired ed dog is crossed with a smooth haired dog. a. Parent Genotypes:[2 Genotypes:[2]] AA x aa b. Dr Draw aw a Punnett Square to show how the possibl possible e offspring may result from this cro cross: ss: [1] A a a A Aa Aa Aa Aa c. What is the genot genotypic ypic ratio ffor or the F1 gener generation?[1] ation?[1] The wired hair gene is dominating 100%, so the ratio is 4:0. 100% Aa and heterozygous. d. What would the phenot phenotypic ypic ratio be for the F2 gener generation? ation? [2] F2 would have the ratio of 3:1, meaning 75% would have wired hair and 25% would have smooth hair. 2. In humans, havin having g a widow’ widow’ss peak is dominant (H) tr trait ait while a str straight aight hairline is a re recessive cessive tr trait ait (h). If a man with a widow’ widow’ss peak has childr children en with a woman that has a str straight aight hairline and they have a child who h has as ype be? Explain you yourr answer answer.. [2] a str straight aight hairline, what must the man's genot genotype The man’s genotype is heterozygous (Hh) because he has a recessive trait, which they must be heterozygous to obtain. If said man were to have a child with the woman, the offsprings’ genotype will be Hh and will not have a recessive trait but due to the genotypes being Hh and hh, there is a 50% chance the children will have a straight hairline. h h H Hh Hh h hh hh 3. In humans, fr free ee earlobes (E) are dom dominant inant to attached earlobes (e) and br brown own eyes (B) are dominant to blue eyes (b). A m man an with free earlobes and bl blue ue eyes marries a woman with at attached tached earlobes and brown eyes. a. What is the genot genotype ype of the man?[2] Eebb b. What is the genot genotype ype of the woman? [2] eeBb NOTE: the man's mother had attached earlobes & the woman's father had blue eyes. c. Complete a Punnett square showing the cross between the woman and the man.[4] Eb Eb eb eb eB EeBb EeBb eeBb eeBb eb Eebb Eebb eebb eebb eB EeBb EeBb eeBb eeBb eb Eebb Eebb eebb eebb d. List the resulting phen phenotypic otypic rratio atio of the children. [2] 4:4:4:4 25%; 25%; 25%; 25%; free earlobes, brown eyes free earlobes, blue eyes attached earlobes, brown eyes attached earlobes, blue eyes 5. In rrats, ats, black hair (B) is dominant to white hair (b). In a cro cross ss between a heterozygous bl black ack haired rrat at with a homozygou homozygouss white haired rat ((Bb Bb x bb); a) What is the chance (or probability) that they will have a white haired rat? 50% [1] b) What is the chance (or probability) that they will have 5 white haired rats in a row? 0.031% [1] erence between Mitosis and Mei Meiosis osis 6. Explain the diff difference Mitosis’s purpose is to create somatic cells asexually, as well as to grow and repair asexual reproduction. It occurs in four stages of a single cell division within the interphase. In animals, mitosis turns into two diploid daughter cells with 46 chromosomes in both cells which are identical. As for meiosis, it makes gametes (reproductive cells) and allows sexual reproduction. It aids in the reproduction of diploid organisms dividing into haploid cells and encourages diversity. Meiosis also repairs genetic defect and unlike mitosis, happens in eight stages instead of four. It’s actions occur within the nucleuses of primordial germ cells and creates four haploid daughter cells, or two pairs. Meiosis results in 23 chromosomes. events ents inv involving olving chromosomes that tak take e place during the ffollowing ollowing portions of the cell 7. Describe the key ev cycle : a. Interphase A phase in which the mitotic divisions of a cell rest. This could also occur meiosis. c. Prophase The first phase of mitosis which separates duplicated genetic material in the nucleus of a parent cell. This produces two identical daughter cells. Chromatin condenses during this phase. d. Metaphase The nucleus dissolves, the cell’s chromosomes condense, and they move together to place themselves in the centre of the dividing cell. e. anaphase 4th phase of mitosis, it separates the genetic material which has been duplicated from the parent cell. e. telophase