Core Biology Practice

What are the main symptoms of Huntington's disease? Please tick each correct answer below.

We have 23 chromosomes in each nucleus of a cell

Huntington's disease and cystic fibrosis are examples of [blank_start]genetic[blank_end] diseases

Genes code for [blank_start]proteins[blank_end]. There are two main types which are structural and functional. Structural is mainly used for cell [blank_start]growth[blank_end] and repair within organisms whereas functional are [blank_start]enzymes[blank_end] which speed up the chemical reactions within the body.

We have genetic variation due to environmental factors. Tick two correct environmental factors below.

A phenotype is the characteristic you show.

The [blank_start]23rd[blank_end] set of chromosomes determine the sex of the human. The person is female if the chromosomes are presented as [blank_start]XX[blank_end] and the person is male if the chromosomes are presented as [blank_start]XY[blank_end]

[blank_start]Alleles[blank_end] are different versions of a gene

When inheriting alleles, there are two main combinations of alleles. Inheriting two of the same alleles is called [blank_start]homozygous[blank_end]. Alternatively inheriting two different alleles is called [blank_start]heterozygous[blank_end].

A [blank_start]dominant[blank_end] allele controls the development of a characteristic even if there is only one of that allele in a chromosome pair. A [blank_start]recessive[blank_end] allele is present on both chromosomes in a pair as an alternative.

Horatio believes that he is at a high risk of heart disease. Which of these factors below could explain the reason for this? Please tick each correct answer.

What is the probability that a child has Huntington's disease if one of the parents is healthy and the other is a parent with the HD gene? You may wish to draw a punnet square to help find your answer.

What are the symptoms of Cystic Fibrosis? Please tick each correct answer below.

The sex of the individual is determined by a gene on the X chromosome.

If the Y chromosome is not present i.e there are two XX chromosomes, the embryo will develop [blank_start]ovaries[blank_end]. Alternatively, if a Y chromosome is present then the embryo will develop [blank_start]testes[blank_end].

[blank_start]Embryonic[blank_end] stem cells are often classified as [blank_start]unspecialised[blank_end] cells as they can develop into any type of cell. Stem cells can become [blank_start]specialised[blank_end] during the developmental process of the embryo/organism.

Clones can be produced by asexual reproduction

Differences between clones are only genetic

For two non-identical twins, their genes are identical to their parents

What is it meant by pre-implantation genetic diagnosis? Please tick two correct answers.

Why might the authorities prevent the use of pre-implantation genetic diagnosis? Tick the BEST answer.

Which two MOST important decisions that parents may have to make after having a genetic test?

Steve is Mary's brother. What sex chromosome did they each receive from their mother?

False negative is when the foetus does not have the disorder as the outcome but does have the disorder in reality

False positives are where the foetus has not got the disorder as the test outcome, but does have the disorder in reality

What is the probability that a conceived child has Cystic Fibrosis if both parents are carriers? You may wish to draw a punnet square to help you in answering this question.

To be a carrier of Cystic Fibrosis, you only need one healthy allele and one allele that has CF