Chapter 7 - Cellular Basis of Inheritance

Prep for Exam 2

The human genome typically has exactly how many chromosomes?

46 chromosomes (23 pairs)

How many copies of each chromosome do diploid cells have?

diploid cells have two copies of each chromosome

What are homologues?

Homologues are the maternal and paternal copies of a chromosome.

What is a sister chromatid?

A sister chromatid is one of two identical copies of a chromosome created during replication.

What occurs during interphase of Meiosis

Each chromosome in a homologous pair replicates to form a sister chromatid.

What occurs during Meiosis I

In the first division of meiosis, the homologous pairs separate.

What occurs during Meiosis II

In the second division of meiosis, the sister chromatids separate. This results in four haploid cells, each containing just one copy of each chromosome.

What is the term for the first chromosomes 1-22

Autosomes

What is the map of chromosomes called?

Karyotype

What are the last two chromosomes (23 and 24) called?

Sex chromosomes (x-mother, y-father)

Determine the syndrome based on the characteristics: short height, underdeveloped ovaries, infertile, and webneck

Turner syndrome (female)

Determine the syndrome based on the characteristics: underdeveloped testes, tall, and infertile

Klinefelter syndrome (male)

Determine the syndrome based on the characteristics: very tall, supermale

XYY Male

Determine the syndrome based on the characteristics: Mental issues and metafemale

XXX Female

Which chromosome is down’s syndrome associated with?

The 21st chromosome

What are some sources of genetic variation

Alleles coming from two parents, crossing over, and the reassortment of homologues

A diploid cell undergoes meiosis. What are the final products of this division?

four haploid cells

Where does crossing over take place?

During meiosis