Download Higher Human Biology Chapter 9 Questions

Chapter 9- Chromosomes and DNA Replication

Name the structures that hold genes.

Name the substance that genes are made from.

What term is used to describe a species characteristic number of chromosomes present
in the nucleus of each cell?

What name is given to the appearance and size of the chromosomes?

What name is given to a pair of chromosomes whose genes match one another?

Although the genes may be the same each may possess different forms of the same
gene e.g. brown eye colour and blue eye colour. What name is given to different forms
of the same gene?

How many chromosomes are found in the nucleus of a human body cell?

How many pairs are these chromosomes arranged as?

What name is given to the 22 pairs that that play no part in sex determination?

What name is given to chromosome pair number 23 that decide the sex of an
individual?

Which two letters are used to describe the sex chromosomes in a (i) female (ii) male?

Which sex chromosome is the smaller one?

What name is given to a cell that contains a double set of chromosomes?

What name is given to a cell that contains a single set of chromosomes?

What symbol is used to represent the (i) haploid number (ii) diploid number?

What name is given to the process by which the nucleus of a normal body cell divides
into 2 new daughter nuclei followed by the division of the cytoplasm to form two new
daughter cells?

How many chromosomes end up in the two new daughter nuclei following mitosis?

Name the process by which the nucleus of a diploid gamete mother cell divides into 4
daughter nuclei followed by the division of the cytoplasm to form 4 sex cells?

How many chromosomes end up in the nucleus of each of these 4 sex cells?

Any cell preparing to undergo meiosis or mitosis must double its quantity of genetic
material to supply the new cells with the correct quantity of genetic material. What
name is given to the doubling of genetic material that must take place prior to meiosis
and mitosis?

What four things must the nucleus contain in order for DNA replication to occur?

Name the enzyme involved in DNA replication.

Put the following steps involved in DNA replication in the correct order
Weak hydrogen bonds are forming between
complimentary base pairs
A region of the original DNA molecule is
unwinding
Free DNA nucleotides are finding and aligning
with its complimentary nucleotide on the
open chain
Weak hydrogen bonds break between bases
causing the component strands of DNA to
unzip/separate and expose their bases
The two new daughter molecules of DNA
each wind up into a double helix
Strong chemical bonds form from phosphate of
one nucleotide to the sugar of the next nucleotide

Following DNA replication and just before Mitosis/Meiosis what do the
chromosomes look like?

Following Mitosis/Meiosis, the chromatids get pulled apart, what are they
known as once they are separated?

Why is DNA replication important?