Questions

In humans all reproduction is sexual. It involves joining together haploid gamete cells from each parent with half the normal number of chromosomes to make a new cell containing both parents' genetic material. This is a diploid zygote. The cells from each parent that combine to form the zygote are called gametes.

Meiosis produces haploid gametes from a diploid parental cell.

Glycolysis involves the breaking down of a sugar into more manageable compounds in order to produce energy.

The net end products of glycolysis are two Pyruvate, two NADH, and two ATP.

Haemoglobin is a protein what carries oxygen in the blood and contains iron metal in it.

A Subquery or Inner query or a Nested query is a query within another SQL query and embedded within the WHERE clause.

Subqueries are most frequently used with the SELECT statement. The basic syntax is as follows::

SELECT column_name [, column_name ]
FROM table1 [, table2 ]
WHERE column_name OPERATOR
(SELECT column_name [, column_name ]
FROM table1 [, table2 ]
[WHERE])

A subquery is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved.

Subqueries can be used with the SELECT, INSERT, UPDATE, and DELETE statements along with the operators like =, <, >, >=, <=, IN, BETWEEN, etc.

There are a few rules that subqueries must follow −

1. Subqueries must be enclosed within parentheses.

2. A subquery can have only one column in the SELECT clause, unless multiple columns are in the main query for the subquery to compare its selected columns.

3. An ORDER BY command cannot be used in a subquery, although the main query can use an ORDER BY. The GROUP BY command can be used to perform the same function as the ORDER BY in a subquery.

4. Subqueries that return more than one row can only be used with multiple value operators such as the IN operator.

5. The SELECT list cannot include any references to values that evaluate to a BLOB, ARRAY, CLOB, or NCLOB.

6. A subquery cannot be immediately enclosed in a set function.

7. The BETWEEN operator cannot be used with a subquery. However, the BETWEEN operator can be used within the subquery.

Oceania is a geographic region comprising Melanesia, Micronesia, Polynesia and Australasia. In Oceani, most towns began as Colonial Ports.

The geologic time scale is subdivided into 4 units called Eon, Era, Periods and Epochs.