Sexual Reproduction and Cloning

What is sexual reproduction?

The process involving the fusion of two gametes (egg and sperm) to form a zygote, producing offspring genetically different from both parents.

Why does sexual reproduction result in genetic variation?

Because offspring inherit half their genetic material from each parent, allowing for new combinations of genes.

What are the two types of fertilisation?

Internal fertilisation and external fertilisation.

What is internal fertilisation?

When sperm fertilises the egg inside the female’s body, common in mammals, reptiles, and birds.

What is external fertilisation?

When sperm and egg combine outside the body, often in aquatic environments like fish or amphibians.

List advantages of sexual reproduction.

High genetic variation, increased adaptability, and higher chance of survival under changing environmental conditions.

List disadvantages of sexual reproduction.

Requires two parents, slower process, and uses more energy to find mates and produce offspring.

What is cloning?

The process of creating an identical copy of an organism or cell from a single parent cell.

What are the two main types of cloning?

Natural cloning and artificial cloning.

What is natural cloning?

Occurs when organisms reproduce asexually or when identical twins form naturally.

What is artificial cloning?

A human-controlled process that produces genetically identical copies of organisms using scientific techniques.

Describe the process of somatic cell nuclear transfer (SCNT).

1 a nucleus is obtained from a somatic cell(donor nucleus)

2 the nucleus is removed from the unfertilised egg

3 the donor nucleus is transferred into the unfertilised egg

4 the embryo is cultured until it forms into a embryo which can be implanted into a surrogate mother where it completes development

What are the advantages for SCNT?

Selects advantageous traits

Allows medicine and research

What are the disadvantages for SCNT?

Low genetic diversity

Animal rights concerns

List advantages of cloning.

Can preserve desirable traits, assist in conservation, and reproduce genetically identical organisms.

What is embryo splitting?

Where an embryo is spilt into multiple smaller embryos which are then implanted into surrogate mothers

The surrogate mothers do not share any genetic material with the offspring

List disadvantages of cloning.

Reduced genetic diversity, potential health problems, and ethical concerns regarding human intervention.