Biology 1 Chapter 13 (Lecture) Flashcards
Heredity
The transmission of traits from one generation to the next.
Genetics
The scientific study of heredity and hereditary variation.
Genes
Discrete units of hereditary info consisting of a specific nucleotide sequences in DNA.
What are Gametes?
Sperm & Eggs
DNA is packaged into…
…Chromosomes. Each chromosomes consists of a single long DNA molecule coiled in association with various protein.
Locus
A gene’s specific location along the length of a chromosome.
Asexual Reproduction
- Genetical identical offspring
- Produced by mitosis
- clone
- 1 parent
Sexual Reproduction
- 2 parents
- Offsprings are identical
Life Cycle
The generation to generation sequence of stages in the reproductive history of an organism from conception to production of its own offspring.
Karyotype
A display of condensed chromosomes arranged in pairs.
A pair of chromosomes have:
- Same length
- Same centromere position
- Same staining pattern
- Are called homologous chromosomes or homologs
Sex Chromosomes: Female
XX
Sex Chromosomes: Male
XY
Non sex chromosomes are called:
Autosomes
The “n” number
The number of chromsomes in a single set (A set is always haploid)
Diploid Cell
Any cell with 2 chromosome sets and is referred to as 2n.
Human diploid number
46
2n=46
Human haploid number
23
(22 autosomes + single sex chromosome)
Fertilization
The union of gametes
Zygote
The fertilized egg and is 2n
The only cells not produced by mitosis are…
… The gametes and they are formed by meiosis
Preceded by replication of chromosomes. (Mitosis)
Yes
Preceded by replication of chromosomes. (Meiosis)
Yes for Meiosis I
No for Meiosis II
Number of cell divisions. (Mitosis)
1
Number of cell divisions. (Meiosis)
2
Results in. (Mitosis)
2 daughter cells (Identical)
Results in. (Meiosis)
4 daughter cells (Not identical)
Number of chromosomes in daughter cells as compared to parent cell. (Mitosis)
Same