Chaptre 6 Flashcards
Genetic diversity?
Inherited genetic differences in a species that give many organisms a survival advantage.
Sexual reproduction?
Reproduction that require two parents and produces off springs that are genetically different from each other, from either parent and from any other member of their species.
Diploid number?
Two sets of chromosomes, the diploid numbers for a human cell is 46
Haploid number?
Each set of inherited chromosomes, half the diploid number (n); humans inherit of 23 chromosomes and one set of 23 chromosomes from their male parents.
Gametes?
Specialized cells necessary for reproduction in a animal, male gametes are sperms and in females they are eggs.
Fertilization?
The process during which an egg cell is penetrated by a sperm cell and the haploid genetic information of both males and females gametes combines.
Embryo?
The stage of a multicellular organism that developed from a zygote.
Meiosis?
The process that produces gametes with half the number of chromosomes as body cells.
Homologous chromosomes?
A pair of matching chromosomes.
Crossing over?
An event in meiosis 1 in which sister chromatids exchange DNA results in variations in gametes.
Independent assortment?
An event in meiosis 1 in which homologous pairs of chromosomes separates and sort themselves into a daughter cells a shuffling of genes that contributes to variations and genetic diversity.
Karyotype?
A photo micrograph that shows the number of chromosomes a person has, as well as their size and shape, prepared by cutting and pasting chromosomes taken from body cells during mitosis; used to diagnose genetic disorders.
Syndromes?
A particular disease or disorder with a specific group of symptoms that occur together.
Mating?
The process by which gametes arrive in the same place at the same time.
External fertilization?
Fertilization in which a sperm cell and an egg cell unite outside the bodies of the parents.
Internal fertilization?
Fertilization in which sperm cells are deposited inside the females body where they meet egg cells.
Pollination?
The transfer of males gametes in pollen from the male reproductive part of a plant to the female reproductive part of a plant.
Ovules?
The female plant structures that contains eggs cells.
Pollen tube?
A structure that delivers sperm cells to egg cells in plants formed after pollen lands on the female part of a plant.
Crossing over?
Crossing over is when a chromosomes pair in meiosis exchange DNA. as a result the chromosomes pick up new genetic DNA. multiple cross overs can occur.
Independent assortment?
It occurs in meiosis 1
Homologous chromosomes separate at the equator and move towards opposite poles of the cell.
For each 23 pairs there are two possibilities for how chromosome will eventually sort itself into daughter cells.
Gamete formation?
Although the process of meiosis is the same for males and females gamete formation is different. In males meiosis 1 occurs and produces 2 cells. Followed by meiosis 2 where those two cells slit equally. In females 2 eggs are produced in meiosis 1 but the division is unequal. One of them has more cytoplasm and organelles. When those eggs go and slit agin they end up with three smaller eggs and 1 super one.
What the function of meiosis?
The process where cells are produced with half as many chromosomes as normal.
Haploid number in humans?
23
Diploid number in humans.
46
What are zygotes?
A fertilized egg.
What are homologous chromosomes?
Chromosomes that cross over and exchange DNA