1. The placenta comprises foetal portion and maternal portion
2. The placenta is highly vascularized to maintain steep diffusion/ concentration gradient for fast exchange/ diffusion of
material between maternal and foetal circulation;
3. Chorionic villi have microvilli on their surfaces to further increase the surface area for exchange of material between
maternal and foetal circulation;
4. Choronic villi are highly branched
johnmulu answered the question on January 18, 2017 at 09:41
- Where in human body are relay neurons found?(Solved)
Where in human body are relay neurons found?
Date posted: January 18, 2017. Answers (1)
- Name the source of progesterone at the following stages(Solved)
Name the source of progesterone
a) Before the fourth month of pregnancy
b) After the fourth month of pregnancy
Date posted: January 18, 2017. Answers (1)
- Distinguish between deoxyribonucleic acid and ribonucleic acid in man in these aspects(Solved)
Distinguish between deoxyribonucleic acid and ribonucleic acid in man in these aspects
a) Chemical composition
b) Function
c) Location in the cell
Date posted: January 18, 2017. Answers (1)
- What is the difference between population and a community?(Solved)
Give the difference between population and a community.
Date posted: January 18, 2017. Answers (1)
- Why doesn't maize plant undergo secondary growth?(Solved)
Explain why a maize plant does not undergo secondary growth.
Date posted: January 18, 2017. Answers (1)
- What is the name of the compound which stores energy that is released during the oxidation of glucose?(Solved)
Name the compound that stores the energy that is released during the oxidation of glucose.
Date posted: January 18, 2017. Answers (1)
- Why is male is referred to as the heterogametic sex?(Solved)
In man, the male is referred to as the heterogametic sex. Explain
Date posted: January 18, 2017. Answers (1)
- Distinguish between transpiration and guttation(Solved)
What is the difference between transpiration and guttation?
Date posted: January 18, 2017. Answers (1)
- Which structural features increase the rate of impulse transmission through a neurone?(Solved)
State two structural features that increase the rate of impulse transmission through a neurone.
Date posted: January 17, 2017. Answers (1)
- A constant supply of oxygen is necessary for plants to efficiently absorb dissplved mineral salts from soil(Solved)
A constant supply of oxygen is necessary for plants to efficiently absorb dissplved mineral salts from soil. Explain
Date posted: January 17, 2017. Answers (1)
- Which feeding structure prevents oxygenated and deoxygenated blood from mixing inside the mamalian heart(Solved)
Name the structure which prevents oxygenated and deoxygenated blood from mixing inside the mammalian heart.
Date posted: January 17, 2017. Answers (1)
- Name one factor that is maintained at a relatively constant level in the body by the following organs(Solved)
Name one factor that is maintained at a relatively constant level in the body by the following organs
i) Liver
ii) Skin
iii) Kidneys
Date posted: January 17, 2017. Answers (1)
- Homeostasis is defined as "the maintenance of a stable internal environment" in the body.(Solved)
Homeostasis is defined as "the maintenance of a stable internal environment" in the body. What is meant by the expression "internal environment"?
Date posted: January 17, 2017. Answers (1)
- Explain why when using an electron microscope to study specimens(Solved)
Explain why when using an electron microscope to study specimens
(a) The images formed are viewed either on a fluorescent screen or photographic plates.
(b) It is not possible to observe living materials
Date posted: January 17, 2017. Answers (1)
- Name two strengthening tissues in plants other than xylem(Solved)
Other than xylem tissue, name two strengthening tissues in plants.
Date posted: January 17, 2017. Answers (1)
- Name the main mineral elements obtained from insects by insectivorous plants(Solved)
Name the main mineral elements obtained from insects by insectivoros plants
Date posted: January 16, 2017. Answers (1)
- State two factors within the seed that cause seed dormancy(Solved)
Which factors within the seed that cause seed dormancy?
Date posted: January 16, 2017. Answers (1)
- Name the ground material of each of the following organelles(Solved)
Name the ground material of each of the following organelles:
a) Chloroplast
b) Nucleus
c) Mitochondrion
d) Plant cell vacuole
Date posted: January 16, 2017. Answers (1)
- Explain why only mutations in the genes of gametes can influence evolution(Solved)
Explain why only mutations in the genes of gametes can influence evolution.
Date posted: January 16, 2017. Answers (1)
- What type of evolution produces analogous structures?(Solved)
Name the type of evolution that produces analogous structures
Date posted: January 16, 2017. Answers (1)