Chapter 8 Test Flashcards
What are the three main functions of cell division?
Reproduction, repair, and growth
This refers to the primary reasons cells undergo division in biological processes.
How do DNA molecules condense into chromosomes?
By being tightly wrapped around proteins called histones
Histones play a critical role in DNA packaging.
What is a sex chromosome?
A chromosome that determines the sex of an organism
In humans, these are X and Y chromosomes.
What is an autosome?
Any chromosome that is not a sex chromosome
Humans have 22 pairs of autosomes.
What is a zygote?
The fertilized egg that results from the union of sperm and egg
It is the first cell of a new organism.
What is a somatic cell?
Any cell of a living organism that is not a germ cell
These are body cells as opposed to reproductive cells.
What is a gamete?
A reproductive cell that fuses with another gamete during fertilization
In humans, these are sperm and egg cells.
What is the role of repair mechanisms in cell division?
They fix any mutations or mistakes made in other phases
These mechanisms occur at the end of G1, S, and G2 phases.
What is abnormal cell growth?
It can be a tumor
Tumors can be benign or malignant.
What happens during crossing over?
Homologous chromosomes swap bits of DNA in prophase 1 of meiosis
This process increases genetic diversity.
How do homologous chromosomes align during metaphase one?
They line up randomly
This random alignment contributes to genetic diversity.
What is duplication in genetics?
A mutation that results in a segment of DNA being copied
It can lead to gene dosage abnormalities.
What is translocation in genetics?
A mutation where a segment of DNA is moved from one chromosome to another
It can disrupt gene function and lead to diseases.
What is nondisjunction?
When homologous chromosomes or sister chromatids fail to separate
This can lead to chromosome abnormalities.
What are the consequences of nondisjunction?
One chromosome may be missing or have an extra chromosome
This can lead to conditions like Turner syndrome or Klinefelter syndrome.
What is Turner syndrome?
A condition caused by a missing or incomplete X chromosome
It affects females and can cause various developmental issues.
What is Klinefelter syndrome?
A condition caused by an extra X chromosome in males
This can affect physical and cognitive development.
What is Down syndrome?
A genetic disorder caused by the presence of an extra copy of chromosome 21
It is characterized by developmental delays and physical features.
True or False: Male individuals have two X chromosomes.
False
Males typically have one X and one Y chromosome.
Fill in the blank: In humans, a _______ is a fertilized egg.
zygote
It marks the beginning of the development of a new organism.
