Answer:
Cell of and integument
Explanation:
When flowering plants reproduce by sexual reproduction, they form seeds contained into fruits. The fruit is derived from the maturation of the flower's ovary (female part) after fertilization.
A mature seed contains three generations:
- a diploid embryo (the new sporophyte),
- The embryo is surrounded by haploid female gametophyte tissue that supplies nutrition
- All the above structure is in turn surrounded by the seed coat (diploid parental sporophyte tissue). The seed coat is produced by integument cells to protect the embryo during its development and before its can germinate. As it is produce by it parental plant, its ploidy level diploid.
In contrast, the generative nucleus and sperm cell are part of male gametophyte (pollen grain) and therefore haploids. Synergid cell is part of embryo sac, therefore belongs to female gametophyte and thus being haploid. Finally, cell of endosperm is usually derived from the fusion between a sperm cell and one of the two female gametes present within the embryo sac, thus being triploid.
The main difference is that organisms that have similar characteristics could be in the same species or have common ancestors
Answer:
Renewable Energy Resources.
Explanation:
Unlike fossil fuels which cannot be recovered when destroyed, these sources of energy can be recovered by a means of recycling . Recycling here reduces solid wastes which is one of the causes of land pollution.
Hydroelectric schemes can only be built in mountain regions where rainfall and rivers are plentiful which involves upset of aquatic ecosystem. This poses a dangerous pollution problem though.
Wind generators and solar panels are not very efficient energy producers. However, future schemes for producing solar energy via solar satellites are promising.
The gene which is produced once or twice in a lifetime is the milk producing hormone after childbirth. This is because it is produced only after the birth of the child. The growth of the mammary glands takes place during pregnancy. The breast continue to increase in size after giving birth to a child. After delivery only copious milk is produced which is generally done with the help of milk hormone. During pregnancy the secretion of the milk is inhibited by the estrogen and progesterone which circulates in the blood stream which in turn inhibits the release of prolactin from the pituitary gland thus making the mammary glands unresponsive. Where as insulin is a hormone which helps the body to utilise the sugar or glucose from different sources like carbohydrates that we get while we eat food and adrenaline is secreted when we are scared or when we feel that we are in danger. Therefore, milk producing hormone is the gene that are turned once or twice in a lifetime.
