BIO - MEIOSIS

If there are two questions in one, separate answers with a SEMICOLON and a SPACE. ex: apple; pear

Meiosis, in animals, is only used to make what cells? Where are these cells produced?

Sex cells, or gametes; testes or ovaries

What are two examples of gametes?

Sperm and eggs

How many cells does meiosis produce? How many sets of chromosomes does each cell have?

4; 1 set each

How many chromosomes do human body cells have? How many do gametes have?

46; 23

What processes does meiosis involve?

Synapsis, crossing over, and two disjunctions

What happens during SYNAPSIS?

Formation of tetrads from homologous chromosomes

What is CROSSING OVER?

Occurs between homologous chromosomes to create new recombinations of genes

What are HOMOLOGOUS chromosome pairs?

Chromosomes that have the same kind of genes in the same place on each chromosome, and the same size.

What body cells contain homologous chromosome pairs? Which never contain homologous pairs?

Normal body cells; normal gametes

What occurs during GAMETOGENISIS

The cells that do meiosis develop into sperm or an egg and 3 polar bodies

What is true about the number of chromosomes in all 4 cells, the egg, and the 3 polar bodies?

They all have the same number of chromosomes

What is true about genetic material?

It always divides equally

What is the purpose of meiosis?

To create new genetic combinations that lead to greater variation in offspring

Why is meiosis neccesary?

It makes it more likely that some of the offspring have the necessary characteristics to survive environmental changes