Midterm Flashcards
Genetics is the study of _____.
Inherited traits
Humans have _____ pairs of chromosomes.
23
A change in a gene’s DNA sequence is a _____.
Mutation
A chart that displays paired chromosomes in order of size is a ______.
Karyotype
The Y chromosome ______.
Is a sex chromosome
A human body has about ______ cells.
30 trillion
Shawn’s mother and Heather’s mother are sisters. Shawn and Heather have _____ of their genes in common.
1/8
Body weight must be a complex trait because ______.
It is inherited to an extent, but can be altered by diet and/or exercise
Identifying individual drug reactions based on genetics is a growing field called _____.
Pharmacogenetics
Select the example of genetics.
Studying how a disease gene is transmitted within a royal family
Sickle-cell anemia results from a beta-globin protein containing the amino acid valine in the place of the amino acid glutamic acid. This is an example of a _____ causing a disease.
Mutation
Select the example of traditional breeding.
Mating dogs with other dogs based on traits such as size, fur color, and temperament
Select the true statement regarding types of cells.
Somatic cells are diploid, meaning that they have two copies of the human genome
Which of the following acts as a quality control center for cells?
Endoplasmic reticulum
The organelle that is the equivalent of a cellular garbage disposal system is the _____.
Lysosome
At the point in the cell cycle when mitosis begins _____.
Each chromosome consists of two identical chromatids joined at the centromere
The two major stages of the cell cycle are _____.
Interphase and mitosis
The order of events in the cell cycle is _____.
G1 to S to G2 to mitosis
Chromosomes coil tightly around chromosomal proteins and condense during _____.
Prophase
During S phase, replicated chromosomes are joined at their _____.
Centromeres
The part of a chromosome that shortens with each cell division, functioning as a “clock,” is the _____.
Telomere
Factors that control how often a cell divides include _____.
Telomere lengths, hormonal signals, crowding, and growth factors
Egg cells are _____.
Haploid germ cells
The first cell that leads to development of a new individual forms when _____.
A sperm and an ovum join
Sperm cells and egg cells (oocytes) are called _____.
Gametes
During the first meiotic division _____.
Homologous chromosome pairs separate
Meiosis is necessary because otherwise _____.
The fertilized ovum will have too much genetic material
The correct sequence for the steps of meiosis I is _____.
prophase-metaphase-anaphase-telophase
Synapsis occurs during
Prophase I
The number of possible chromosome combinations in a human gamete, considering independent assortment but not crossing over, is about _____.
8 million
Secondary spermatocytes and secondary oocytes are _____.
Haploid
At the end of meiosis, the number of chromosomes in each daughter cell is halved because meiosis has _____.
Two cell divisions after one DNA replication
After the second meiotic division, the number of chromosomes in each daughter cell is _____ that of the original parental cell.
Half
The number of sperm cells that form from a primary spermatocyte is _____.
4
By the end of meiosis I of oogenesis, an oogonium becomes _____.
A secondary oocyte and a polar body
Meiosis in females _____.
Is completed only if an oocyte is fertilized
After a sperm penetrates the oocyte, the ovum’s nuclear membrane disassembles and the two sets of chromosomes approach each other. At this point, the sets of chromosomes are called _____.
Pronuclei
Fertilization usually occurs in the _____.
Uterine tube
A cell from an organism that has a diploid number of 6 chromosomes has 3 chromosomes lined up in the center of the cell, each chromosome containing two joined sister chromatids. What phase of the cell cycle is this cell in?
Metaphase II of meiosis
The difference in mode of inheritance between Huntington disease and cystic fibrosis is that _____.
Huntington disease does not skip generations, but cystic fibrosis can