Question

The process of sexual reproduction versus several forms of parthenogenesis sexual reproduction haploid parthenogenesis diploid parthenogenesis meiosis meiosis automixis meiosis apomixis mitosis oocyte (immature female egg cell) spermatocyte (male sperm cell) oocyte oocyte female egg cell diploid zygote chromosome replication fuse with other oocyte haploid zygote (2n 2n diploid egg develops into diploid individual diploid zygote develops into haploid individual haploid (2n) diploid develops into diploid individual develops into diploid individual © Encyclopædia Britannica, Inc. Answer the questions below in your notebook (not on this sheet). Be prepared to put your answers on the board. Use only the diagrams to address the items below. 1. Define haploid and diploid. State the difference between the two. 2. In sexual reproduction, which process leads to a reduction in the number of chromosomes? What process restores the diploid condition? 3. Briefly, in a sentence or two, explain what happens in "haploid parthenogenesis." 4. In one sentence, clearly state the difference between haploid and diploid parthenogenesis. 5. Briefly, in a few sentences, describe the main differences between automixis and apomixis. 6. Describe Mueller's ratchet and why it only applies to asexual populations.

Answer 1

01.

Answer –

Haploid - is the condition of a cell where the cell has half the number of chromosomes or actually the number of chromosomes present after meiosis. Meiosis leads to a reduction in number of chromosomes as a result each daughter has half the number of chromosomes as compared to parent cell before meiosis. In general term, haploid is define as the number of chromosomes present in a a gamete.

For example, after meiosis in case of sexual reproduction or in case of haploid parthenogenesis or in case of diploid parthenogenesis meiosis leads to the formation of a cell (spermatocyte or oocyte respectively) which has half the number of chromosomes i.e. if initial number of chromosomes is 2n then after meiosis these cells have n number of chromosomes.

Diploid state of a cell is basically defined as a cell which has two of sets of chromosomes. A set of chromosomes is basically a group or collection of all the different types of chromosomes present in a cell. For example, a Drosophila cell has 4 different kinds of chromosomes, now these 4 chromosomes form a set of chromosomes.

If we use the above diagram then as n represent a single set of chromosome thus cells which have two sets of chromosomes (n + n = 2n) will be diploid cells as can be seen in case diploid zygotes which are formed in sexual reproduction and/or in diploid parthenogenesis.

The given question is a type of question with multiple questions (question 1-6) and according to HomeworkLib guidelines under the given condition answer only the first question unless the student has specified (which is not in the given case). Thus, I answered only the first question i.e. Question-1.