genetics exam 1 lecture questions

Variants of a gene are called?

alleles

The difference between phenotype and genotype is that

genotype refers to the genetic instructions and phenotype to their expression

A group of scientists meet to discuss the legal implications of genome editing in humans. This is an example of

bioethics

Ribosomes are in the cells of

all organisms

The cellular basis of muscular dystrophy is that some of a child’s muscle cells

lack a protein that enables them to withstand the force of contraction

In mitosis, what is the correct order of steps?

prophase, metaphase, anaphase, telophase

Mitosis is _____ while cytokinesis is _____

division of the nucleus; division of the cytoplasm and organelles

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

Gametes produced from one meiotic event

each have the same chromosome number

Crossing over occurs during

prophase I

Cystic fibrosis is autosomal recessive. This means that _____

both sexes can be affected and can “skip” generations through carriers

A person who has identical alleles for a particular gene is _____ for that gene.

homozygous

The wild type eye color for humans is

brown

Some combinations of recessive alleles cause problems so severe that a fetus may cease to develop. Such lethal allele combinations appear to alter mendelian ratios because

homozygotes for the lethal allele do not appear as a progeny class

Different alleles that are both expressed in a heterozygote are

codominant