Questions

The principal hormone secreted by the corpus luteum is progesterone. Menstruation is triggered by a drop in the levels of progesterone.

The statement "A communist government is led by one political party" is what best defiines a communist government. Here in this type of government, the power is in the hands of the one political party and it only controls the political and economic systems of the country/state.

Matching blood group before marriage is important. This is to prevent Rh incompatibility. Rh incompatibility can lead to erythroblastosis fetalis (Hemolytic disease of the newborn-HDN). Fetal RBC gets destroyed & newborn may get severe anaemia, jaundice. This jaundice is more severe than Physiological jaundice ( which is the most common and will usually resolve on its own).

In very severe form, a fetus may die due to heart failure. This is mediated by the antigen-antibodies reaction. Transfer of maternal antibodies across the placenta occurs. This happens when Rh +ve man marries Rh-ve lady.

So Rh +ve man should try to avoid marrying Rh-ve lady.

Matching blood groups for marriage ::

Boy : A = Girl : A & AB 

Boy : B = Girl : B & AB 

Boy : O = Girl : O, A, B & AB 

Boy : AB = Girl : AB 

Boy : Rh+ve = Girl : Rh+ve 

Boy : Rh-ve = Girl : Rh+ve & Rh-ve.

Blood groups that do not match for marriage ::

Boy : A = Girl : O & B 

Boy : B = Girl : O & A 

Boy : AB = Girl : O, A & B 

Boy : Rh+ve = Girl : Rh-ve.

Kingdom is the smallest level of classification.

The level of classification from largest to smallest is :

* Domain

* Kingdom

* Phylum

* Class

* Order

* Family

* Genus

* Species

The process accounts for species diversity is Meiosis. Meiosis is termed as a specialized cell division which reduces chromosomes number by half and then creates for haploid cells.

An atom is the smallest particle of a substance. Chemical substances are divided into two major groups. They are

1. Pure Substances (and)

2. Mixtures.

There are two types of pure substances that are Elements and Compounds.

Elements : An element is a substance that is made up of only one kind of atoms and cannot be broken down into simpler substances by chemical means. Metals and Non- metals come under elements.

Examples of elements are Iron, Silver, Gold, Mercury etc.

Compounds : A Compound is a substance that is formed when two or more elements combine chemically.

Examples of compounds are Water, Carbon dioxide, methane, vinegar etc.

Mixtures : A Mixture is formed when two or more substances mixed together but not chemically combined.

Example: Air.

The currency of Japan is Japanese yen.