L41 BIOL 2970 Lecture Notes - Lecture 7: Amniocentesis, Raphanus, Colchicine

37 views3 pages

salmonyak403

2 Nov 2016

School

WUSTL

Department

Biology And Biomedical Sciences

Course

L41 BIOL 2970

Professor

Duncan Ian

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Crossing over/ unit dna reduced near telomere and near centromere: like deletions, duplications cause deleterious effects when heterozygous with +, in humans _> see dysmorphic development, played a key role in evolution, each gene has an essential function. 1/1600 progeny are wild type, or extreme bar (ultrabar) these exceptional types arise by crossing over. Some chromosomes in humans have 1, 2, 3, 4, or 5 green genes. Red and green opsins are 98%, similar in a. a. sequence. If red and green pair, crossing over occurs. If only a small piece of red gene = red blind. If only a small piece of green gene = green blind. If a little green and extra red = anomalous green vision. Heterozygosity for paracentric inversions does not cause production of inviable zygotes. Multigene family: groups of genes that encode related proteins, that presumably arose by duplication and divergence. Ring will orient with 2 centromeres directed to one pole and 2 to the other.

Related Questions

___1. Nationally, the most common cause of Down Syndrome is
a. nondisjunction of Chromosome 21 during meiosis
b. translocation of Chromosome 21 onto another chromosome
c. inversion of a large section of Chromosome 21
d. deletion of the Down Syndrome gene
___2. In humans, sex is determined by
a. The presence or absence of the Y chromosome
b. The ratio of X chromosomes to sets of autosomes
c. The temperature during fetal development
d. Which parent is stronger at the time of conception
___3. A translocation is
a. a chromosomal abnormality in which a piece of one chromosome breaks off and attaches to a different chromosome
b. an abnormality in which the chromosomes are translocated out of the nucleus
c. a condition in which the chromosome has broken in two places and come back together with the middle segment backward
d. an abnormality in which there is an extra copy of one chromosome
___ 4. In snapdragons, a red-flowered plant crossed with a white-flowered plant produces all pink-flowered offspring. But crossing two pink-flowered plants produces red, pink, and white in a 1:2:1 ratio. This is a good example of
a. Incomplete dominance
b. Dominance of the red allele over the white allele
c. Lethal effects of the pink allele
d. Sex-linkage of the flower-color alleles
___ 5. If a person with type AB blood marries a person with Type O blood, what blood types are possible in their children? (Assume this trait is a single-gene trait, not complicated by interaction with other genes).
a. A, B, AB, or O
b. A or B only
c. AB or O only
d. AB only 2
___6. In what phase of meiosis are haploid nuclei first formed? a. Anaphase I b. Metaphase II c. Telophase II d. Metaphase I e. Telophase I
___7. What is the phenotype of a heterozygous tall pea plant? a. tall b. Tt c. TT d. tt e. dominant
___ 8. If genes A and B are far apart on a chromosome, and A and C are close together, which of the following observations is expected?
a. Crossing over will occur more often between A and C than between A and B
b. Crossing over will occur at equal frequencies between A and C, and between A and B
c. Crossing over will occur more often between A and B than between A and C
___9. Sometimes an organismâs genotype for one gene masks the effect of a different gene. This phenomenon is called
a. Dominance
b. Incomplete dominance
c. Co-dominance
d. Epistasis
e. Variable expressivity
___10. The dominant allele of a gene is
a. The one that is expressed most often in a population
b. The one that is expressed most often in any particular cross
c. The one that is expressed in an individual that has two different alleles
d. The one that is most healthy to have, that gives the greatest fitness
___11. In human cells, DNA replication occurs
a. In S phase of interphase
b. In G1 phase of interphase
c. In G2 phase of interphase
d. In prophase of mitosis
e. Whenever the cell needs to read the DNA to make proteins
___ 12. A process in which recipient cells take up genes from DNA molecules floating free in the surrounding medium is called
a. conjugation
b. specialized transduction
c. generalized transduction
d. transformation 3
___ 13. Most calico cats are female. However, a few rare males are observed. What is the genotype of a male calico cat?
a. X BX 0
b. X OY
c. X BY
d. X BYY
e. X BX OY
___ 14. A type of red-green color-blindness is a sex-linked (X-linked) recessive trait in humans. Can a woman have this type of color-blindness?
a. Yes, a woman could be color-blind if her mother and father were both heterozygous.
b. Yes, a woman could be color-blind but only if she has an abnormal number of sex chromosomes.
c. No, women can't show sex-linked traits because they lack a Y chromosome.
d. No, women can't show sex-linked traits because they have two X chromosomes.
e. Yes, a woman could be color-blind if her father was color-blind and her mother was a carrier (heterozygous).

L41 BIOL 2970 Lecture Notes - Lecture 7: Amniocentesis, Raphanus, Colchicine

Document Summary

Get access

Related Documents

BIOL 1001 Chapter : Chapter 10 Notes

GEN-3000 Study Guide - Midterm Guide: Metaphase, Aneuploidy, Meiosis

BIOL 112 Lecture Notes - Lecture 16: Punnett Square, Color Blindness, Mendelian Inheritance

Related Questions