Question

Lecture 7: Cellular Respiration

1. Explain the advantages that occur within populations of sexually reproducing organisms have over asexually reproducing organisms?

2. Describe the two events which occur that are common to all sexually reproducing organisms and how they fit into the different life cycle of those organisms.

3. Explain how the random alignment of the homologous chromosomes during metaphase I contributes to the variation in gametes produced by meiosis.

4. Describe the ways in what ways meiosis II is similar and varies from the mitosis of a diploid cell?

5. What is meiosis, and what makes it important to what sexual reproduction requires for the diploid organisms?

Hello to the amazing universe and help out there can you please help me answer these short essay questions as required with details that our required within Biology 130. The answer should be short essay answer. That just answers the question. These have been challenging and hopefully can get that superhero support.

Thank you in advance to the one who can help me get these answered and submitted! May a center and positive energy your way for helping getting these answered and ready to submit the final episode.

-Bio Student-

Answer 1

1. Sexually reproducing organism produces gametes by a type of cell division called as meiosis. This type of cell division involves crossing over of the homologous chromosomes. The process of crossing over brings number of changes in the gene combinations resulting in recombinanation. Because of the recombination of the genes, variations occur in the population. Offspring produced are not exactly same as the parent organisms. Variations are important in a opulation for adaptations to occur. A population tha has variations and is capable of adapting, can survive any changes in the environment. Because the population is not exactly similar to each other, any disease will not affect the entire population.

Brings variations in population, allows population to adapt, all individuals do not suffer a disease.

So these are the advantages of the population which is reproducing sexually.

2. The events that occur in all sexually reproducing organisms is gamete formation by meiosis and fusion of thee gametes to produce zygote. The process is called fertilization.

Meiosis occurs during the gamete formation with in the gonads. Testis present in male produces gametes called sperms which are capable of movement and they are very small. Ovary present in female produces gamete called the Ovum which is incapable of movement, big in size and has lot of nutrients. The two gametes are either released in to the water if the organism is aquatic form and fertilization occurs in water. Such fertilization is called external fertilization. In all terrestrial forms, the male gamete is released in to the female body during the process of mating, fusion of these gametes occurs in the female body. Such fertilization is called internal fertilization. Animals have a specific season, during which they produce gametes and breed.

3. Every diploid cell has paired chromosomes. The paired chromosomes are similar in all respects except that they differ in the alleles of the genes they have. Such paired chromosomes are called homologous chromosomes. One of these is from mother parent and another is form the father parent. When such homologous chromosomes allign on the equator during meiosis I, they allign randomly. Which means any combination of mother and father chromosomes can move to a pole. Diference in allgnment produces variations in gametes.

4. Meiosis II has chromosomes that have undergone crossing over. That is why they are recombinant chromsomes and differ from the parental chromosomes. The cell in meiosis II also does not have homologous chromsomes because during meiosis I, the homologous chromosomes got separated. These are differences.

Similarities are--

During prophase, metaphase, anaphase and telophase all changes occuring are similar. Durinng metaphase one spindle fiber gets attached to one chromosome. Duting anaphase, chromatids separate to form daughter chromosmes.

5. Meiosis is a reductional division. Which means, the diploid organism is able to produce haploid gametes because of the ability of meiosis to reduce chromosomal number ot half. It is important to reduce chromosomal number, so that the number of chromosomes remains constant in generations. If the chromosmes number is not reduced to half, fertilization will result in doublng of chromosomes in the next generation.