The Heritability of Mutations in Sex Cells Flashcards
changes in DNA sequence that can affect genetic traits
can occur in any cell, but only those in sex cells can be passed to offspring
Genetic Mutations
types of mutation (3)
point
insertion
deletion
single nucleotide change
point
Addition of 1+ nucleotides
insertion
Loss of 1+ nucleotides
deletion
leads to frameshift mutation is more damaging
causes changes in the subsequent amino acid sequences in a polypeptide chain
insertion / deletion of sequence of nucleotides
alter reading frame of the genetic code, have a significant effect on the gene product.
frameshift mutation
include sperm & eggs.
sex cells
other term for sex cells
gametes
Each carries half the genetic information of an organism.
Mutations in these cells can be passed to the next generation.
sex cells
changes to your DNA that you inherit from egg & sperm cells during conception
germline mutation
changes to your DNA that happen after conception to cells other than the egg and sperm
passed to daughter cells during mitosis but not to offspring during sexual reproduction.
somatic mutation
occur in sex cells
heritable
germline mutations
occur in body cells
NOT passed to offspring
somatic mutations
less significant than germ mutations
somatic mutation
cell division process that creates sex cells
meiosis
involves 2 rounds of division 🟰in 4 unique cells.
meiosis
most important cells in the body for generation of an organism as they transmit necessary genetic information to form a new human being.
germ cells
only have one half of the total amount of human genetic information.
germ cells
passed from parent ▶️ offspring
these must occur in sex cells BEFORE fertilization
heritable mutation
Not all mutations are harmful; some can be (1) ____ or (2) ______.
1 beneficial
2 neutral
Carriers of genetic information in form of DNA.
chromosomes
humans cells have: ___ chromosomes and __ pairs?
46
23
centromere of each chromosome
short (p) arm
long (q) arm
MOST COMMON TYPE of chromosomal abnormality
aneuploidy
caused by an extra or missing chromosome
aneuploidy
Changes in chromosome number, such as trisomy or monosomy.
numerical aberration
Changes in chromosome structure
structural aberration
types of chromosomal aberrations
numerical
structural
types of structural aberrations
translocation
inversion
duplication
ring chromosomes
Segments of chromosomes break off and attach to different chromosomes.
translocation
Segments of a chromosome are reversed end to end
inversions
Segments of a chromosome are copied, repeated.
duplications
Ends of a chromosome join to form a ring
ring chromosomes
Visualizing chromosomes under a microscope to identify structural and numerical changes
karyotyping
Using fluorescent probes to detect specific chromosome abnormalities
Fluorescence in situ hybridization (FISH)
Comparing patient DNA with reference DNA to find variations
Comparative Genomic Hybridization (CGH)
Causes of Mutations in Sex Cells
Environmental factors: Radiation, chemicals, viruses
Errors during DNA replication
Random chance during cell division
environmental factors that might increase mutation rates
tobacco smoke
UV light
aristolochic acid
Some heritable mutations can lead to: ___ ?
genetic disorders
often caused by specific mutations in sex cells
Cystic fibrosis, sickle cell anemia, hemophilia
show effects even if only one copy is present.
dominant mutation
require two copies to show effects.
recessive mutation
can identify mutations in sex cells
can inform individuals about potential risks for children
can also guide family planning decisions
genetic testing
Changes in structure/number of chromosomes
Chromosomal Mutations in Sex Cells
lead to rapid evolution but also 🔼 genetic disorders
high mutation rates
lead to stagnation, reduced adaptability
low mutation rates
risks of high mutation rates in a population
genetic disorders, reduced fitness & survival chances, evolutionary instability
benefits of high mutation rate in a population
genetic diversity, evolutionary innovation, adaptive evolution
Chromosomal Mutations in Sex Cells examples
Down syndrome, Klinefelter syndrome, Turner syndrome
