Chapter 13 (Inheritance/Meiosis) Flashcards
What is heredity?
transmission of traits from one generation to the next
What is variation?
demonstrated by differences in appearance that offspring show from parents and springs (each offspring has different combo)
What is genetics?
the scientific study of heredity and variation
What are genes?
units of heredity
What are genes made of?
segments of DNA
How are genes passed to the next generation?
gametes (reproductive cells)
How many chromosomes do humans have in the somatic cells?
46 chromosomes (46 of these X)
What cells of the body have 46 chromosomes?
somatic cells
What is a locus?
a gene’s specific position along a chromosome
What happens to genes in asexual reproduction?
single individual passed all genes to offspring without fusion of gametes
What is the offspring of an asexual reproductive organism called?
clones
What happens to genes in sexual reproduction?
two parents give rise to offspring that have a unique combo of genes inherited from parents of the parents
What is a life cycle?
generation sequence of stages in the reproductive history of an organism
How many pairs of chromosomes do humans have?
23 pairs
What is a karyotype?
ordered display of pairs of chromosomes from a cell
What are homologous chromosomes?
one of a pair of chromosomes with the same gene sequence, loci, chromosomal length, and centromere location (X)
What are homologous pairs?
consists of one paternal and one maternal chromosome (X X) consisting of the genes controlling the same inherited characters
What are sex chromosomes?
23rd pair of chromosomes that determines gender (X and Y)
What is the homologous pair of females?
XX (FEMALES ONLY HAVE THE HOMOLGOUS SEX CHROMOSOME)
What is the chromosomal pair of males?
XY
What are the remaining 22 pairs of chromosomes called?
autosomal chromosomes
What is a diploid cell?
represented by 2n, has two sets of chromosomes
What is the diploid number for humans?
46
What is a haploid cell?
gametes, represented by n (n=23)
What is the sex chromosome in an ovum?
X
What is the sex chromosome in a sperm?
can be either X or Y
What is fertilization?
union of gametes (sperm and egg)
What is a fertilized egg called?
zygote