During mitosis division two daughter cells are produced having same number of chromosome. In meiosis division four daughter cells having half the number of chromosomes are produced. So, haploid organisms follow mitosis division.

Apomixis is modified form of reproduction in plants in which seeds are formed without fusion of gametes. The diploid cell of nucellus develops into an embryo giving a diploid seeds.

• Parthenocarpy is the method of fertilizing fruit without development.
• In botany and horticulture, parthenocarpy(literally meaning "virgin fruit") is the natural or artificially induced production of fruit without fertilization of ovules, which makes the fruit seedless.
• Stenospermocarpy may also produce apparently seedless fruit, but the seeds are actually aborted while they are still small.
• Parthenocarpy (or stenospermocarpy) occasionally occurs as a mutation in nature; if it affects every flower the plant can no longer sexually reproduce but might be able to propagate by apomixis or by vegetative means.

Bryophyllum plants grow in marshy areas where seeds are not able to germinate. The leaf margin of Bryophyllum contains numerous plantlets before falling on muddy land.

Life cycle of organism’s starts from growth and development followed by reproductive phase. After that senescence phase starts in which degenerative changes starts which is generally irreversible and leads to death of organisms.

Since drones are developed without fertilization of egg, they are developed by parthenogenesis. Queen and worker honey bees are developed by fertilization of egg.

Senescence is a natural process followed by maturity of organism. The metabolic processes of organisms start slowing down in this process leading to wear and tear of vital body organ. Nutrition does not affect the process of senescence.

The period from birth to natural death of an organism is known as its life span. It varies from few years to thousand years, depending on the organism.

During vegetative propagation, new organisms are formed by single plant parts. So, new individuals are genetically similar to each other and there is no genetic variation.

Asexual mode of reproduction in yeast takes place by budding process in which small outgrowth develops on tips followed by karyokinesis. Same process is repeated several times to form chain of yeast cells.

The male and female reproductive parts of flower are stamen and carpel. If both stamen and pistil are present in same flower, the flower is called monoecious.

The menstrual cycle in human being is repeated at the interval of 28/29 days. It starts with raptures of inner lining of uterus. In the middle of menstrual cycle ovulation takes place.

In Viviparous, well developed young one is produced by female at the end of gestation period. There is no fear of predator of outer environment as in case of oviparous in which young one comes out of egg. Viviparous mode of development is not influenced by adverse environmental conditions.

In angiosperms, female gametophyte is called embryo sac which is 7-celled but 8-nucleated structure. Embryo sac is formed inside the ovary that changes into seeds after fertilisation.

Meristematic tissue change into permanent tissue by the process of differentiation. The permanent tissue becomes meristematic due to de-differentiation.

Sexual reproduction in mammals involves cyclic changes during which ovum is released. In primitive animals it is called oestrus cycle and in in primates including human being it is called menstrual cycle.

Sporopollenin is present in exine of pollen grains in plants. It is one of the most resistant organic substances and can withstand high temperature, strong acids and alkali. No enzyme that degrades sporopollenin is so far known. This sporopollenin helps the pollen grain to be well preserved. 

The exine is composed of sporopollenin which is the polymer that is resistant to oxidation and leaching.

During sexual reproduction male and female gametes are fused together to form zygote. The gene from two different sources mix together and develops some new features in new progeny. The new traits help the organisms to survive in adverse condition also.

Ovulation is the process of release of ovum from ovary. Menstrual cycle begin with menstrual bleeding. Increase in FSH and LH hormone leads to release of ovum from ovary in the middle of menstrual cycle. In human female ovulation occurs on the 14-15th day of beginning of menstrual cycle.

Unisexuality promotes or favours the cross pollination (xenogamy) and prevent self pollination (Autogamy). Geitnogamy involve transfer of pollen grain between two flowers of the same plant so unisexuality will not prevent geitonogamy.

Egg and antipodal cells are haploid structure as they are formed by meiosis cell divisions in which number of chromosome reduce to half. This kinds of division occurs only during gamete formation.

Wind is the most common means of pollination in flowering plants. The pollen grain must be light and dry and in large number to facilitate pollination. Flower with one or few ovules are pollinated by wind to ensure fertilisation.

Sequence of events in reproduction in flowers:

1. Pollination - It is the process by which pollen is transferred from anther and stigma.
2. Fertilization -It is the process of fusion of male and female gamete. Once the pollen tube enters into synergid male gametes are released. One of male gamete fuses with the egg and forms diploid cell zygote and this is called syngamy. Other male gamete fuses with two polar nuclei to form endosperm and this is called triple fusion  because of fusion of three haploid nuclei. The whole process is called double fertilization.
3. Embryo formation - Development of embryo from zygote.
4. Seedling - Seed enclose embryo and covered by seed coat.

Therefore, the correct answer is option C.

• Cleavage is a series of rapid mitotic divisions of the zygote which converts the single celled zygote into a multicellular structure called blastula
• All cleavage divisions are mitotic. The number of resultant blastomeres increases following an arithmetic progression.
• Cleavage results in a solid ball of cells, Morula having 8-16 cells, then it descends towards the uterus.
• Outer peripheral cells enlarge and flattens further to form trophoblast which interiorly creates a cavity called blastocoel.
• With the formation of blastocoel, morula is converted into blastula which is the hollow spherical structure also called as blastocyst in mammals.