Unit 1 Section 3: Reproduction and Meiosis

Question 1

Budding

Answer 1

yeast can reproduce via budding.

1. the yeast swells on one side forming a bud on it’s surface
2. the cell indergoes interphase (DNA & organelle replicated)
3. Begins mitosis (replicated DNA & organelle move into the bud)
4. nuclear division is complete, the budding cell has a nucleus with identical DNA to the parent cell
5. Cytokinesis - the bud pinches off producing a yeast cell genetically identical to the Parent cell

Question 2

sexual reproduction

Answer 2

two gametes join together at fertilisation to form a zygote, which divides and develops into a new organism.

Question 3

-loid chromosomes

Answer 3

diploid number - 23 pairs 46 chromosomes

Haploid number - 23 chromosomes

Question 4

homologous pair

Answer 4

pair of chromosomes that:

• Same size
• Same Genes
• Same position of gene
• may have different alleles

Question 5

Meiosis

Answer 5

happens in the reproductive organs to produce gametes
cells that divide by meiosis are originally diploid, the gametes formed are haploid,
cells formed are all genetically different
it’s broken into 5 main steps.

Question 6

step 1:

Answer 6

The DNA Replicates and coils to form chromosomes. they arrange themselves into homologous pairs

Question 7

step 2:

Answer 7

the chromosomepairs swap pieces wth each other so they have a new combination of alleles

Question 8

step 3:

Answer 8

the cell divides splitting up the homologous pairs, any chromosome from each pair can go into each pair as long as each cell gets one number 1 and one number 2 etc.

Question 9

step 4:

Answer 9

the new cells divide again, splitting each chromosome in half. any half can go into any cell

Question 10

step 5:

Answer 10

four genetically different haploid cells are produced.