Week 8 - Genetics

Question 1

What are some relevant nursing actions?

Answer 1

• Standard (social) and aseptic (procedural) hand washing.
• Personal protective equipment (protection against DNA or RNA viral infections).
• Genetic counselling
• Pharmacogenetics
• Administration of prescribed antibiotics.

Question 2

What is Sex Chromosomes?

Answer 2

Determine maleness /femaleness

Question 3

What is Genotype?

Answer 3

Genetic makeup (DNA sequence)

Question 4

What is Phenotype?

Answer 4

Expression of a genetic trait / characteristic (showing)

Question 5

What is Alleles?

Answer 5

Genes for the same trait that may have different expressions

Question 6

What is Homozygote?

Answer 6

Individual who has identical alleles for a trait

Question 7

What is Heterozygote?

Answer 7

Individual who has different alleles for a trait

Question 8

What is Dominant?

Answer 8

Allele that masks the expression of a less potent allele

Question 9

What is Recessive?

Answer 9

Less potent allele; expressed only in homozygote

Question 10

What is Centromere?

Answer 10

Narrowest region of a chromosome

Question 11

What is Telomere?

Answer 11

Found on both ends of a chromosome

Question 12

State the number of chromosomes in the nucleus of most human cells

Answer 12

46 (23 pairs, one set from each parent)

Question 13

Identify in which phase of meiosis I and II could a chromosome separation error occur

Answer 13

• Anaphase 1 or 2
• Chromosomal non-dysfunction, where chromosome pair or chromatid pair not separated
• Results in wrong number of chromosomes (or chromatids) in sex cells (eggs, sperm)

Question 13

Once meiosis has been completed, the genetic information in the FOUR new cells is not the same. Describe the three sexual processes that facilitate this genetic diversity

Answer 13

• Genetic recombination (Prophase 1)
• Independent assortment (Metaphase 1)
• Random fertilisation

Question 14

Name the phase of meiosis in which the DNA is replicated so that each chromosome becomes composed of two chromatids

Answer 14

Interphase

Question 15

Explain why men are more likely to have red-green colour blindness and haemophilia

Answer 15

• Women have two X chromosomes, men have one
• Men have no second chance of inheriting a normal allele if they have one abnormal allele on their X chromosome.

Question 16

Name the phase of meiosis in which the DNA is exchanged between the paternal and maternal chromosomes

Answer 16

Prophase

Question 17

Identify the major role(s) of meiosis II

Answer 17

Split each chromosome (of two chromatids) into two separate chromatids (=chromosomes)

Question 17

Name the phase of meiosis in which the independent assortment of paternal and maternal chromosomes take place

Answer 17

Metaphase

Question 18

State five statements about genetics

Answer 18

• Chromatids, telomeres and centromeres are terms associated with chromosomes
• Sequence of nitrogenous bases in DNA codes for the sequence of amino acids in proteins
• Meiosis introduces genetic variability and halves the chromosome number
• Most traits are determined by the interaction of multiple genes
• A genotype does not always produce the expected phenotype

Question 19

State five statements about inheritance

Answer 19

• Dominant alleles mask the expression (protein production) of recessive alleles
• A heterozygote has a different allele for a certain trait (characteristic)
• Mitochondria possess multiple copies of a circular chromosome
• Epigenetics markers are chemical tags on DNA that influence gene expression
• The number of microbiota genes far exceeds the number of human genes

Question 20

DNA in the human body includes that of the nucleus, mitochondria and microbiota. The ratio of microbial to human genes is _____ to one.

Answer 20

100

Question 21

A disruption to the microbiota is known as _____.

Answer 21

Dysbiosis