Science

Crossing-over occurs in Prophase I of meiosis.
During crossing-over, homologous chromosomes line up along their length, intersect a section of their chromatids, and exchange corresponding parts of that chromatid with each other. So in the end, one of the homologous chromosomes has a segment of the other homologous chromosome's DNA, and vice versa.
Keep in mind that the DNA they exchange codes for the same thing; the genes that are on the DNA code for the same traits as well.
Genetic recombination occurs in Anaphase I of meiosis. The homologous chromosomes are separated, and each resulting daughter cell has one of each pair of homologous chromosomes. However, the combination of what cell gets what chromosomes is completely random- for instance, pretend a parent cell has two pairs of homologous chromosomes; in the first pair, both are large, and one is green and one is blue. In the second pair, both are small and one is green and one is blue.
During Anaphase I, the pairs separate- each daughter cell gets one big and one small chromosome. The "recombination" is that which chromosome the cells get is completely random. It could be that one cell gets the big green, small blue- or the big green, small green- or the big blue, small green- or the big blue, small blue. There are so many combinations. which makes for much genetic variation!

Application and admissions
Applications for PhD study in India should be made well in advance of the start date for your proposed programme of study. This is because the process of gaining admission to an Indian university can involve various stages and you will need to have confirmed your place on a PhD programme before you can apply for a student visa.
Admissions requirements
Indian universities are free to set their own standards for admission to PhD programmes, but most will require a similar set of application materials. These should include a research proposal, detailing the proposed outline of your PhD project, and explaining the methodology you plan to employ.
Most Indian PhD programmes will expect you to have completed a postgraduate Masters, but you may be able to apply with a good undergraduate degree if you can demonstrate sufficient experience and expertise in your proposed field. Most common international qualifications will be recognised by Indian universities. If in doubt, you can contact the Association of Indian Universities or ask for advice from your specific institution.
Examinations and interviews
India is relatively unique in requiring all prospective PhD students to sit an entrance examination before being admitted to undertake doctoral research. This is referred to as the National Eligibility Test (NET) and is administered by the University Grants Commission (UGC) for most subjects, with the exception of Science and Engineering which are covered by the Council of Scientific and Industrial Research (CSIR). As you may have noticed, Indian Higher Education is quite fond of acronyms!
In some cases, you may also be required to attend an interview at your university (this is more likely if you are applying to an Institute of National Importance). Interview procedure varies among institutions, but may involve giving a presentation on your proposed research topic. Universities may not be able to assist with travel and accommodation costs for international students attending an interview and you are advised to check in advance if this is part of the admissions process at your proposed institution.
Indian universities will usually charge an application fee, but this is nominal - often no more than ?100 ($1.5).

No, you can not get into NASA after D Pharma.
You can get into NASA as a Geologist!
I would like to quote legendary astronaut Dr. Sally K. Ride :
"The most important steps that I followed were studying math and Science in school. I was always interested in physics and astronomy and chemistry, and I continued to study those subjects through high school and college on into graduate school. That's what prepared me for being an astronaut; it actually gave me the qualifications to be selected to be an astronaut. I think the advice that I would give to any kids who want to be astronauts is to make sure that they realize that NASA is looking for people with a whole variety of backgrounds: they are looking for medical doctors, microbiologists, geologists, physicists, electrical engineers. So find something that you really like and then pursue it as far as you can and NASA is apt to be interested in that profession."
So yes if you are very much into Geology, you can definitely make your way to NASA.
But before that you should know that,
You need to have an American citizenship.
NASA gives preference to Educators.
So you'll need to plan accordingly.
Now coming to our Indian Space Research Organisation (ISRO)
Oh yes! They too recruit Geologist.
Indian Institute of Remote Sensing (IIRS), a unit of Indian Space Research Organisation (ISRO), is a premier institute for capacity building and research in the field of remote sensing and geoinformatics. The Institute has a multi-disciplinary and problem oriented research agenda focusing on developing land-ocean-atmosphere applications and understanding Earth's surface and subsurface processes using primarily the space-based technologies. The research programmes are intricately linked to overall goal of ISRO towards operationalisation of space-based services for national development.
You should definitely go through this link: Indian Space Research Organisation Recruitment 2015 - 39,100 Salary
It will for sure give you an idea about the requirements for getting into ISRO as a Geologist.
On a lighter note :)

Biochemists generally pursue research related work in the following fields.
Medicine :Biochemists, in this field carry out diagnostic tests and investigations for finding out causes of diseases. Their major concern is to study the role of genetic transmission of diseases from one generation to another.
They also try to figure out the chemical changes that take place in the cells of the body parts which signal the onset of various diseases such as tuberculosis, cancer, diabetes, mental disorders like epilepsy etc. Research related to identification and analysis of chemical processes like muscular contraction, reproduction, metabolism etc also relates to their job.
Agriculture :Biochemists develop and innovate new improved techniques for crop cultivation, pest control management and crop storage management. Contributions made in this field by biochemists has helped to better the output and quality of agricultural produce.
Nutrition : In this field, biochemists have researched and studied the effects of certain food stuff, minerals, proteins, carbohydrates, fats and vitamins, when consumed in excess or in deficient quantities, on the human body. The mechanism of fermentation process which has been practised for the past many years was discovered by biochemists only.