Genomes and SNPs (7)

Question 1

What are single nucleotide polymorphisms?

Answer 1

Single nucleotide polymorphisms (STP) are genetic variations in a DNA sequence that occur when a single nucleotide is substituted for another nucleotide.

Question 2

SNPS are considered to be ____ mutations that have been evolutionary successful enough to recur in a significant ____ of a population of a species.

Answer 2

point

proportion

Question 3

SNPS occur throughout the human genome-about one in every ____ nucleotide base pairs. This means that there are about 10 million SNPS within the 3- billion-nucleotide human genome.

Answer 3

300

Question 4

What are modern insights helping us in terms of SNPs?

Answer 4

Modern insights into these genetic variations are changing the understanding of inheritance.

Question 5

Where do SNPs act most of the time?

Answer 5

Most commonly, these variations are found in the non-coding DNA between genes.

Question 6

What can SNPs act as?

Answer 6

They can act as biological markers helping scientists locate genes that are associated with the disease.

Question 7

What is a genome?

Answer 7

A genome is the complete set of genetic instructions (genes) necessary to create an organism.

Question 8

Nearly every somatic cell in the body has a ____copy of a genome. Each species has a ____ genome although the genome of individuals of the same species may vary slightly due to mutations.

Answer 8

complete

unique

Question 9

What is The Human Genome Project (HGP)?

Answer 9

The Human Genome Project (HGP) is an international scientific research project set up in 1990.

Question 10

What were the goals of The Human Genome Project (HGP)? (2)

Answer 10

• The primary goal was to: determine the sequence of chemical base pairs which make up human DNA (DNA sequencing)
• To identify and map all the genes of the human genome from both a physical and a functional point of view.

Question 11

What happens as researchers learn more about the function of genes and proteins?

Answer 11

As researchers learn more about the function of genes and proteins, this knowledge will have a major impact in the fields of medicine, biotechnology and life sciences.

Question 12

More than 1800 genes causing diseases have already been discovered, e.g. the:

• ___ gene associated with increased risk of breast cancer.
• ___ gene linked to Alzheimer’s disease.
• ___ receptor gene linked to bad cholesterol and heart disease.

Answer 12

RCA2
Apo-E
LDL

Question 13

Many ___, ___ and ___ issues have arisen since the human genome was sequenced, e.g. patenting of genes or creating designer babies.

Answer 13

ethical
legal
social

Question 14

What are genetic counsellors?

Answer 14

Genetic counselors are health professionals with specialized graduate degrees and experience in the areas of medical genetics and counseling. They usually work as part of a healthcare team and through genetic counseling they provide information and support to families who have members with birth defects or genetic disorders, such as Down syndrome, Huntington’s disease, physical handicaps, deafness, cancers, etc.

Question 15

As the hereditary (or genetic) conditions may be passed on from parent to children, many genetic diseases or disorders tend to run in families. What do counselors do as a result?

Answer 15

Counselors, therefore, study family and medical histories to analyze inheritance patterns and the risks of the problem recurring.

Question 16

Genetic counselling also aims to provide families with options as to the best way to manage the disorder and can refer families or individuals to appropriate ___ ___structures.

Answer 16

social support

Question 17

What sort of issues could be discussed with a genetic counsellor? (4)

Answer 17

• Should a couple have children if both are ‘carriers’ of a faulty gene, or should they adopt a child?
• Is artificial insemination by a donor or embryo a practical alternative to the donation problem?
• Is in vitro fertilization and the testing of embryos prior to implantation a possible option?
• Should cousins ​​contemplate having children?

Question 18

In humans the pattern of inheritance of a particular characteristic researching a ____ ____, if appropriate records of the ancestors exist.

Answer 18

family pedigree

Question 19

What does a family tree show?

Answer 19

A family tree shows both the genotypes and phenotypes of several generations of individuals in a family. Individuals may have a normal phenotype but be carriers of a genetic disorder, with the mutant allele being recessive.

Question 20

How are family trees useful?

Answer 20

Many disorders are caused by genes that are not functioning properly. These genes can be passed on from generation to generation. A family tree can be constructed to predict whether a couple is likely to pass on a genetic disorder. (For example, if a couple gives birth to a child with a disease such as cystic fibrosis, they can arrange to see a genetic counsellor.)

Question 21

In trying to work out the chance of their next child being born with the disease, what must the genetic counsellor know?

Answer 21

The genetic counsellor must know as much as possible about the parents’ genetic make-up. This information is then used to build up a family tree to show how certain features are inherited and whether they may occur in the next generation.