c17/18 chromosomal basis of inheritance Flashcards
The genetic material that resides within chromosomes is Blank______
DNA
After DNA replication in a heterozygote, the two sister chromatids on a single chromosome contain Blank______
identical alleles
The Blank______ alignment of chromosomes in meiosis I leads to the independent assortment of alleles on different chromosomes
random
The chromosomes that are different in males and females, and which come in a pair, are termed _______
sex chromosomes
Correct factor that determines the sex of an individual: x-y system
presence or absence of the y chromosome
Correct factor that determines the sex of an individual: x-o system
ratio between x chromosomes and autosome sets
Correct factor that determines the sex of an individual: haploidiploid system
haploid or diploid set of chromosomes
Correct factor that determines the sex of an individual: z-w system
presence or absence of the w chromosome
The genetic material of a cell is the ______ within chromosomes
DNA
A gene found on the X chromosome and not on the Y chromosome is designated as an X-______ gene
linked
In meiosis, when a cell prepares to divide, the homologs replicate so that each homolog consists of a pair of
sister chromatids
Independent assortment of alleles of different genes can be explained by the random alignment of _____ ______ of chromosomes during meiosis 1
homologous pairs
The sex chromosomes refer to a distinctive pair of chromosomes that vary between _____ and ______ individuals
male and female
What are the three general rules for genes that follow a Mendelian pattern of inheritance?
- the genes obey Mendel’s law of segregation
- for crosses involving 2 or more genes, the genes obey Mendel’s law of independent assortment
- genes are generally passed unaltered from cell to cell, and from generation to generation
Match each sex determination system with a representative species.: x-y
human
Match each sex determination system with a representative species.: x-o
fruit fly
Match each sex determination system with a representative species.: z-w
bird
Match each sex determination system with a representative species.: haplodiploid
bee
Which of the following statements are true regarding epigenetics?
- variations are reversible from one generation to the next
- variations of gene expression that are unrelated to DNA sequence variants
- Epigenetic changes may be transmitted to offspring
- epigenetic changes are transmissible from cell to cell
What are genes exclusively located on the X chromosome called?
x-linked
Genomic imprinting is an example of a phenomenon called ____ inheritance
epigenetic
One of the first imprinted genes to be identified was a gene in mice called Igf2. This gene encodes a growth hormone called ____-like growth _____ 2 (lgf2)
- insulin
- factor
In genomic imprinting, the transcription of the imprinted gene is inhibited because Blank______.
the DNA is methylated
Mendelian inheritance is characterized by three general rules: 1. Except in the case of rare _________, genes are passed unaltered from generation to generation; 2. Each gene obeys Mendel’s law of _________; and 3. During crosses, two or more genes obey Mendel’s law of independent ________
.
- mutations
- segregation
- assortment
What type of inheritance describes X-chromosome inactivation
epigenetic
The term which describes changes in gene expression that are not related to variations of the DNA sequence, yet are transmissible and are reversible, is _____
epigenetic
What type of inheritance describes genomic imprinting?
epigenetic
What is a Barr body?
a highly condensed x chromosome
The gene Igf2 encodes a(n) Blank_____
growth hormone
The cells of humans and other mammals are able to inactivate all but one of the X chromosomes, because these cells have the ability to _____ their x chromosomes
count
The marking process that occurs during genomic imprinting is the addition of ____ groups to DNA
methyl
Adult, wild-type mice with genotype AA for the Agouti gene will have what color coat hairs?
brown with black tips
The process of X-chromosome inactivation occurs during embryonic development in female mammals and leads to the silencing of one of the two X chromosomes found in somatic cells. This is an example of a(n) _______ change
epigenetic
A true association occurs when Blank______.
two variables follow a pattern
In eukaryotes, where are genes found?
- mitochondria
- chloroplasts
- the nucleus
A highly condensed X chromosome is known as a(n) ______ body
barr
What is the phenomenon called in which a trait of the offspring is solely determined by the value of the trait in the female parent because it is passed on via the organelles in the egg cell?
maternal inheritance
In humans and other mammals, X chromosomes are counted. This process ensures that any normal somatic cell contains ______ active x chromosome(s)
one
In humans, mitochondria are inherited through a type of uniparental inheritance called ____ inheritance
maternal
In mice, the Agouti gene regulates Blank______.
the deposition of yellow pigment in hair
Which phenomenon describes the presence of two genes very close to each other on the same chromosome, and which are transmitted together as a unit?
linkage
In statistics, changes in two variables that follow a pattern is termed a(n) Blank______.
association
Which of the following hypotheses did Thomas Hunt Morgan propose for the unexpected results he obtained when studying transmission of genes in Drosophila?
- genes located on the same chromosome are more likely to be inherited together, violating Mendel’s law of independent assortment
- crossing over occurs during meiosis, allowing chromosomes to create new allele combinations
- the likelihood of a crossover between genes is related to how far apart they are on the chromosome
Which of the following statements about eukaryotic genes is TRUE?
most, but not all genes, are found in the nucleus
The determination of the arrangement of genes in a species’ genome is called Blank______
genetic mapping
In a particular plant, the pigmentation of the offspring depends exclusively on the pigmentation of the female parent. This phenomenon is known as ____ inheritance
maternal
How are mitochondria inherited in humans?
maternal inheritance
When two genes are located close to one another on a chromosome, they tend to be transmitted together. This phenomenon is known as
linkage
Thomas Hunt Morgan recognized that some genes in Drosophila violated the law of independent assortment. He proposed that such genes were located on the same chromosome and that new combinations of alleles could be created only if ____ ______ occurred during meiosis
crossing over
Determining the linear order and the distance between genes on the same chromosome is the purpose of genetic _____
mapping
