Implantation is the major sign of pregnancy for various women, it is a stage in which a zygote of fertilized egg limplants into the wall of the uterus. 
Implantation usually takes place 6 to 10 days post ovulation, or day 20 to 24 of a menstrual cycle. However, it can take place a few days later or earlier. Once fertilization takes place, the egg remains the fallopian tuve for three days prior of getting inside the uterus and starts to implant itself to the walls of the uterus. 
 
        
             
        
        
        
Answer:
D
Explanation:
Prokaryotic cells have no nucleus, eukaryotic cells do. A squirrel is eukaryotic, therefore it’s genetic material will be stored in the nucleus.
 
        
             
        
        
        
Thin Skin. The epidermis differs from that of thick skin in having thinner stratum spinosum, granulosum, and corneum, and lacks the stratum lucidum (Thin Skin 1). The dermis is not arranged in ridges, but does project into the epidermis as true papillae. However, no epidermal ridges are produced
        
             
        
        
        
Answer:
5. The correct answer would be an option A. ova
Note: I assume that all the samples are of human origin.
DNA (deoxyribonucleic acid) content of somatic cells of humans consists of 46 chromosomes or 23 pairs of chromosomes. Gametes (sperm or ova) are haploid cells produced by the process of meiosis and contain half the number of chromosomes found in parent cell. Hence, they contain 23 chromosomes.
6. The correct answer would be an option J.
Sperm formation or spermatogenesis is the process by which spermatozoa (haploid gamete) is produced from germ cell with the help of meiotic division.
Meiosis results in the formation of four haploid (n) cells from single diploid (2n) parent cell. Here, 2n is given as 8 so, n would be equal to 4.
Meiosis I results in the formation of two secondary spermatocyte cells (both haploid or 4 chromosomes in this case) from single primary spermatocyte (diploid or 8 chromosome in this case).
Both the secondary spermatocytes undergo meiosis II to produce 4 spermatids (each haploid or 4 chromosome in this case). Spermatids differentiate and mature into spermatozoa.
 
        
             
        
        
        
Answer: nervous system
Explanation:
The nerves send impulses either from the brain or spinal chord for the body organs to coordinate