The paramecium has two nuclei, a big and small one. The big one operates as the director of the cell's activities, rather like a little brain. The smaller one is used for reproduction. The paramecium splits in half (fission) just as the ameba does. First the smaller nucleus splits in half and each half goes to either end of the paramecium. Then the bigger nucleus splits and the whole paramecium splits. Occasionally two paramecium exchange material and form a new paramecium. This is called conjugation.
<span>Conjugation in Paramecia occurs in the following way: </span>
<span>a). The formation of ciliary contacts. </span>
<span>b). Local loss of cilia and formation of narrow contacts between anterioventral somatic cell membranes </span>
<span>c). Formation of small cytoplasmic bridges (which allow for the exchange of molecular components only). </span>
<span>d). Their enlargement enables the cells to exchange micronuclei. </span>
<span>Bacteria exchange plasmid material and the Paramecia exchange micronuclei.
Good luck to Steve! How is it in Neptune? XD</span>
<span>Genetic variation can be caused by mutation (which can
create entirely new alleles in a population), random mating, random
fertilization, and recombination between homologous chromosomes during
meiosis (which reshuffles alleles within an organism's offspring)</span>
The male
human has a sperm cell and the female has an egg cell. The cells from the male
and female that combine to form a zygote are called gametes. The human sperm
and egg cells each contain 23 chromosomes. . A combination of gametes forms a
zygote with 46 chromosomes. The type of cell division that produces gametes
with half the normal chromosome number is the meiosis. Meiosis is the type of
cell division used in sexual reproduction. It will occur in the testes and
ovaries.<span>Chromosomes get
shuffled when eggs and sperm are made. Though most adult cells contain two sets
of chromosomes, sperm and egg cells are different. These special cells have
just one chromosome from each pair. Which chromosome they get from each pair is
random, making each sperm or egg cell unique. There is also a bit of mixing
before the chromosomes are sorted into individual sperm or egg cells.
Chromosomes from each pair in a mother or father, respectively, make contact
and exchange pieces of DNA, creating hybrid chromosomes. </span>
1 - A ground level plant develops curling tendrils that wrap around other objects so it can "climb".
This is a species changing over time as it was originally a ground level plant but began to climb higher.
2 - Over many generations.
This is because diversity takes time and has to be integrated through generations; for instance, marriage. In a family, it becomes more diverse after the next generation as each generation is likely to marry someone of another ethnicity and allow the family tree to become more diverse.
3 - Mutate or Survive
It depends on what it means by mutate - develop a mutation to make it adaptable? If that's the case, then mutations within the DNA would be a result of adaptation and increase survival. Otherwise, survive is the obvious answer as adaption allows for species to move around and live longer.
Hope this helps!
