placenta in human beings is formed by :
amnion
chorion
allantois
chorion and allantois
answer: b
solution: n/a
i&#39;ve read before the baby attaches to the uterus or forms a placenta, it doesn&#39;t get material from the blood directly. instead it gets it from the yolk sack and the uterine lining. some use this as an okay to drink during two week wait. 10/12 circulation – process of pressure driven bulk flow of blood to all parts of the body  pressure relies on cardiovascular components  heart o four chambered pump  blood vessels o tubes heart pumps fluid in to o arteries, arterioles, capillaries, venules, and veins structure of the heart  right atrium o receives deoxygenated blood from body  right ventricle o pumps deoxygenated blood to lungs  left atrium o receives oxygenated blood from the lungs  left ventricle o pumps oxygenated blood from the body  fibrous skeleton o separates atria from ventricles  so atria work as one unit and ventricles work as separate unit o forms t chloroplast is a powerhouse for the synthesis of carbohydrates in plants. it is broadly divided into three parts (fig 3) namely:a) membrane: chloroplast is double walled organelle viz. it contains inner and outer membrane.b) stroma corresponds to the cytoplasm of chloroplast. it also serves as site for dark reaction of photosynthesis to take place.c) thylakoids/ granum: thylakoids contains chlorophyll that absorbs light. stacks of thylakoids are known as granum.fig 3 shows different parts of chloroplast peculiarities of the dna structure: dna is a double helical structure having nucleotides. these nucleotides are made of deoxyribose sugar, phosphoric acid and nitrogenous bases such as adenine, thymine, cytosine and guanine. the nucleotide sequence of the dna molecule is called a gene. genes are present on dna. a type of gene is responsible for the synthesis of a particular protein. changes in the gene can alter the characteristics of the organisms. using the long division method: pure substances are made up of same type of particles or atoms. all the elements and compounds are pure substances because they contain the same kinds of particles. examples: hydrogen, carbon dioxide a)



antipodals side is called chalazal end.

b) becausethe cells get packed with reserve food supplies, used for providing the nutrition to the developing embryo.

c)cells with 16 chromosomes is calledzygote and cells with 24 chromosome is called endosperm the ligamentum venosum are fibrous remnants that travel between the porta hepatis, the liver, and the inferior vena cava. these remnants are usually obliterated when a person reaches adulthood.
the caudet lobe or lobule of information is below. hello,
dear usually first delivery mein aisa ho jata hai ki baby apna head jaldi engage nahi karta and japan start hoti hai tabhi baby apna hai neeche ki taraf se kya hota hai. 
aap daily thodi walk kare usse baby ka hai jaldi neeche aayega.
yeh bahut normal hai and ismai chinta vali koi baat nahi hai.