Heredity and Genetics

Question 1

What are the 2 types of pairs of genes?

Answer 1

Homozygous: both alleles are the same
Heterozygous: alleles are different

Question 2

What is a genotype vs a phenotype?

Answer 2

Genotype is the gene posessed, can be XX, Xx or xx, can have dominant and recessive alleles
Phenotype is the characteristic displayed based on the genotype

Question 3

What is sex-linked inheritance?

Answer 3

The 23rd pair of chromosomes codes for sex, either XX (female) or XY (male)
The 23rd chromosome also codes for other genes which are not related to sex, but are contained within the 23rd
Ex. red-green colourblindness, hemophilia (not able to form blood clots) etc.

Question 4

What are Autosomal heredity disorders?

Answer 4

Carried by the other 22 chromosomes, not sex-linked

CF, Huntingtons, sicle cell anemia etc.

Question 5

What is polygenic inheritance?

Answer 5

Traits are determined by many genes throughout the chromosomes

Question 6

What is point mutation?

Answer 6

When a single nucleotide is affected by a mutation

This can affect the entire structure of a protein

Question 7

What is spontaneous mutation?

Answer 7

Mutation that arises naturally through mistakes in replication or meiosis

Question 8

What is induced mutation?

Answer 8

Mutation arises from external conditions known as mutagenic agents

Question 9

How is infertility defined?

Answer 9

The inability to get pregnant after 12 months of regular, unprotected sex
40% male, 50% female and 10% unknown
About 1 in 7 couples experience difficulty

Question 10

Describe intrauterine insemination.

Answer 10

Involves injecting the sperm into the uterus within 6 hours of ovulation
Sperm is seperated from semen
Causes little or no pain
Success rate is low, 6-20%

Question 11

Explain assisted reproductive technology

Answer 11

A category of reproductive technology Involves removing eggs, mixing them with perm, then returning them to the woman’s body
28% success rate
Includes IVF, GIFT, ZIFT and ICSI

Question 12

Describe in vitro fertilization.

Answer 12

Most commonly used
Woman takes fertility drugs to assist egg production
Eggs are retrieved
Eggs are combined with sperm from male
Fertilized egg develops in a lab for a few days
Healthy embryos returned to the woman’s body

Question 13

Describe gamete intrafallopian transfer.

Answer 13

Ovulation induction, egg retrieval and sperm collection the same as IVF
Eggs mixed with sperm and immediately returned to the woman’s body
Fertilization occurs in the fallopian tube

Question 14

What are some controversies surrounding reproductive technologies

Answer 14

Criteria for treatment of infertility being debated
Age can affect fertility and whether someone can qualify
IVF increases chance for multiple pregnancies and premature births (can affect development)

Question 15

Explain the advantages of preimplantation genetic diagnosis

Answer 15

Involves removing a single cell and testing for genetic defects
Can reduce the chance of issues
Not always accurate
Can lead to issues
Expensive

Question 16

Explain the concept of ‘Designer Babies’.

Answer 16

PGD (testing for certain genes) can lead to individuals wanting to choose characteristics of their children
Ethical issue with deciding on characteristics

Question 17

Explain the difference between Embryonic stem cells and Somatic stem cells.

Answer 17

Embryonic come from embryos, usually unused embryos (leads to potential ethical issues)
Somatic come from the body of a developed person (Heart, brain, bone marrow etc.)

Question 18

Explain the process of cloning.

Answer 18

Insert DNA to be cloned into a bacterial plasmid. The plasmid will serve as a carrier.
Expose bacterial cells to the plasmid. some cells will pick up the plasmid by transformation (antibiotic gene is added too so the affected bacteria will survive and unaffected bacteria dies)
As the bacterial cell replicates, it makes many copies of the DNA