Meiosis

Meiosis

Meiosis

• •The form of cell division by which gametes, with half the number of chromosomes, are produced.

• •Meiosis is sexual reproduction.

• •Diploid (2n)    ® haploid (n)

Fertilization

• The fusion of a sperm and egg to form a zygote

• •A zygote is a fertilized egg

• 
  

Multiple Choice

Humans have how may chromosomes ?

• 112
• 46
• 8
• 67

Multiple Choice

The male sex cell is called

• egg
• zygote
• sperm
• mitosis

Multiple Choice

The type of reproduction in which the genetic material from two different cells combine

• budding
• chromosomes
• diploid
• sexual reproduction

Multiple Choice

What is it called when a sperm and egg meet?

• meiosis
• fertilization
• cell division
• mitosis

Meiosis

• •Sex cells divide to produce gametes (sperm or egg).

• Gametes have half the # of chromosomes

Meiosis I (four phases)

• •four phases:

   a. prophase I

   b. metaphase I

   c. anaphase I

   d. telophase I

• 
  

Prophase I

• Longest and most complex phase 

• Synapsis occurs: homologous chromosomes come together 

Homologous Chromosomes

• Humans have 23 pairs of homologous chromosomes

• •Homologous pairs (tetrads) carry genes controlling the same inherited traits.

Karyotype

• •A method of organizing the chromosomes of a cell in relation to number, size, and type.

• 
  

Multiple Choice

A human being has a somatic cell that has 46 chromosomes.  What is the haploid number found in a gamete?

• 23
• 46
• 69
• 92

Metaphase I

• •Shortest phase

• Orientation of homologous pair to poles 

Telophase I

Multiple Choice

Human eggs and sperm are _____, and each has ____ chromosomes.

• diploid, 23
• diploid, 46
• haploid, 23
• haploid, 46

Multiple Choice

How many daughter cells are produced from meiosis ?

• 10
• 6
• 4
• 2

Multiple Choice

Meiosis makes sperm and egg cells. In humans, sperm and egg cells each have _____ chromosomes. Therefore a fertilized human egg cell (sperm and egg cell combined) would create a cell with _____ chromosomes.

• 23, 46
• 46, 23
• 2, 4
• 50, 100

Multiple Choice

If the diploid number of carrots is 18, the haploid number is

• 18

• 9

• 27

• 36

Multiple Choice

The chromosomes that pair up during meiosis, are called __________ chromosomes.  

• homozygous 
• asexual
• homologous
• genes