Meiosis

Question 1

difference between “bacterial sex” to “true” sex

Answer 1

Bacterial Cells go through conjugation resulting in the exchange of plasmids.

True sex is the combination of haploid ova and sperm cells resulting in a diploid zygote

Question 2

Process of Gametogenesis for males and females

Answer 2

Males in gametogenesis/spermagenesis undergo meiosis normally giving each 4 cells equal amounts of cytoplasm.
-Females undergo meiosis like males except one reproductive cell receives the majority of cytoplasm resulting in one egg and 3 polar bodies

Question 3

How does independent assortment result in genetic diversity of gametes by shuffling alleles of two or more genes located on DIFFERENT chromosome types

Answer 3

There is no dictated order for what chromosome goes where, so mom and dad chromosomes are randomly assigned to a cell

Question 4

Use concepts of independent assortment and crossing over to explain how it is possible for the offspring of a single self-fertilizing parent to have different combinations of alleles that are not present in that parent

Answer 4

Crossing over and the independent assortment of maternal and paternal chromosomes ensures that each gamete is genetically unique. This is because if the genes are unlinked then crossing over can occur and that will mix alleles and create a different combination then was present in the parent

Question 5

Relate recombination of alleles of linked genes to crossing-over during meiosis

Answer 5

Crossing over CAN create new combinations of alleles of linked genes (if genes are unlinked crossing over will not occur) it is expected that we will see a 50-50 ratio of parental and recombinant after crossing over of linked genes.

Question 6

Define these terms: plasmid, gamete, gametophyte, sporophyte, diploid versus haploid-dominated life cycle and alternation of generations, ploidy,

Answer 6

Plasmid: A plasmid is a small circular DNA molecule found in bacteria and some other microscopic organisms. Plasmids are physically separate from chromosomal DNA and replicate independently. They are very important for bacterial evolution and adaptation to the changing environment, as they carry genes that carry beneficial traits for the bacterial cell. Different types of plasmids can coexist in one bacterial cell

Gamete and gametophyte: Gametes are sex cells (sperm, eggs), when plants reproduce they produce spores that are like gametes in humans. the spores are created and they undergo mitotic cell division and end up producing 2 identical daughter cells that grow up into multicellular bodies that look nothing like the parents, these are called Gametophytes. they are able to create a diploid organisms.

diploid versus haploid-dominated life cycle and alternation of generations: Nearly all animals have a diploid-dominant life cycle in which the only haploid cells are the gametes. Early in the development of an animal embryo, special diploid cells, called germ cells, are made in the gonads (testes and ovaries).
In the haploid-dominant life cycle, the multicellular stage is haploid. The diploid stage is a spore that undergoes meiosis to produce cells that will divide mitotically to produce new multicellular organisms. Fungi have a haploid-dominant life cycle.

Ploidy: The number of sets of chromosomes in a cell or an organism. For example, Humans are diploid, and most of the body’s cells contain 23 chromosome pairs so that would be a ploidy of 2n (n representing a number of chromosome pairs).