He was a Belgain cytologist who was observing cells in different roundworms.
What did Van Beneden propose in 1887?
That an egg and a sperm each containing half the complement of chromosomes found in other cells, fuse to produce a single cell called a zygote
What is fertilization? Or syngamy?
The fusion of gametes to form a new cell
is a form of cell division in which the number of chromosomes is halved during gamete formation.
Having two sets of chromosomes
Has one set of chromosomes.
reproduction that involves the alternation of meiosis and fertizilation.
reproduce by mitotic division and does not involve the fusion of gametes.
True or False- Some organisms are able to reproduce both sexually and asexually
(fill in) When haploid cells encounter environmental stress haploid cells sometimes fuse with other haploid cells to form diploid cells but the cell will later undergo ------- to reform into the haploid phase
All the diploid body cells of an animal that are not involved in gamete formation
gamete-producing, diploid. and undergo meiosis producing haploid gametes
serves to seperate the homologous chromosomes.
Serves to seperate the sister chromatids
At the end of meiosis you end up with --- haploid cells
Because there was --- replication of DNA but --- cell divisions the process reduces the number of chromosomes by half.
Meosis I and meosis II have how many stages
They each have 4 stages
Stages of meiosis I are...
The final result of meiosis II is
4 cells containing haploid sets of chromosomes
A junction between a neuron and another neuron or muscle cell. The 2 cells do not touch. Neurotransmitters cross the narrow space between them.
the chromosome homologues do not replicate between the 2 nuclear divisions.
the differences between meiosis and mitosis
In animals the majority of their life cycle is devoted to the_____stage
Protists spend most of their life cycle in the ____ stage
Plants spend time equally between ______ and _____ stage
haploid and diploid stage
When male gamete meets female gamete they combine to make a