Chapter 13- Repoduction

Question 1

Asexual reproduction —>

Answer 1

Reproduction from one parent organism by simple cell division, for example done by strawberries, bacteria, black worms. This creates identical offspring, although they will now be susceptible to the same diseases

Question 2

Sexual reproduction —>

Answer 2

The fusion of female and male gametes, for example humans, jellyfish, hydra plants, yeast cells etc. The gametes are specials by haploid cells produced by meiosis.

Question 3

Meiosis —>

Answer 3

Interphase
Prophase 1
Metaphase 1 
Anaphase 1
Telophase 1
Prophase 2- two separate cells  
Metaphase 2 
Anaphase 2
Telophase 2- turned into 4 daughter cells

Question 4

Mitosis —>

Answer 4

Divides for 10% of its time- grows new nucleus and goes through cytokinesis (nuclei going to opposite sides of the cells)
90% of its time is in interphase where they do it’s function and grow and become specialised

Question 5

What organisms can reproduce both asexually and sexually?

Answer 5

Malaria parasites
Strawberries
Fungi

Question 6

Why do fungi reproduce both sexually and asexually?

Answer 6

Because then they can have variation but also they can release spores that can grow their offspring

Question 7

What is the structure of a gene?

Answer 7

They have 4 bases called A and T, G and C
T and C are small ones, and A and G are the bigger ones
The edges of the gene is called a sugar phosphate backbone
They change the order of the bases to create different proteins
The T and A are double bonded, whilst the C and G are triple bonded
The polygon is called the detoxysise sugar, whilst the ball is called a phosphate and the square is the base
The right side of the gene is anti-parallel (the polygons are upside down)

Question 8

What is a dominant allele?

Answer 8

Only need one chromosome plus in the pair. It is written in capital letters

Question 9

What is a recessive allele?

Answer 9

Needs both chromosomes in the pair to be recessive. Written in lower case letters.

Question 10

What is a carrier?

Answer 10

When a disease is recessive and has an upper case and lower case letter, they do not have the disease.
Example is cystic fibrosis which is a disorder of the cell membranes. Lungs produce a thick mucus which causes blockages

Question 11

What is a dominant disease?

Answer 11

Polydactyly, which is where you have an extra digit, finger or toe, and they cannot be a carrier, only have the disease or don’t.