MEIOSIS

Question 1

WHICH OF THE FOLLOWING STATEMENTS IS TRUE?

Answer 1

HUMANS HAVE 2 DIFFERENT COPIES OF ONE GENE.

• ONE FROM THE MOTHER AND ONE FROM THE FATHER EACH VARIATION OF A GENE IS REFERRED TO AS AN ALLELE.

THEREFORE, OFFSPRING WILL HAVE 2 ALLELES FOR EACH GENE.

Question 2

WHICH OF THE FOLLOWING IS TRUE REGARDING CROSSING OVER / RECOMBINATION?

Answer 2

CROSSING OVER OR RECOMBINATION CREATES GENETIC DIVERSITY. CROSSING OVER CONTRIBUTES TO THE FACT THAT ALL 4 GAMETES (AT THE END OF MEIOSIS II) WILL BE DIFFERENT FROM EACH OTHER + DIFFERENT FROM THEIR PARENT CELL.

*THE PURPOSE OF CROSSING OVER/RECOMBINATION IS THAT IT CREATES GENETIC DIVERSITY. THIS PROCESS BASICALLY CREATES RANDOM VARIATION OF GENES/ALLELES + CHROMOSOMES WITHIN EACH CELL. THIS IS WHY AT THE END OF MEIOSIS II THERE ARE 4 DIFFERENT GAMETE CELLS

GENETIC VARIATION IS WHAT MAKES EVERYONE UNIQUE.

Question 3

TRUE OR FALSE
THE PURPOSE OF MEIOSIS IS TO CREATE SOMATIC CELLS

Answer 3

FALSE

• THE PURPOSE OF MEIOSIS IS TO CREATE SEX CELLS OR “GAMETES”. WHEN MEIOSIS HAPPENS IN FEMALES IT PRODUCES EGGS

WHEN MEIOSIS HAPPENS IN MALES IT PRODUCES SPERM

SOMATIC IS REFFERING TO BODY CELLS THAT ARE PRODUCED IN MITOSIS.

Question 3

HOMOLOGOUS CHROMOSOMES __________________________

Answer 3

-ARE A PAIR OF CHROMOSOMES THAT ARE RELATIVELY THE SAME IN APPEARANCE + SHAPE

• THE ALLELES ON THESE CHROMOSOMES CODE FOR THE SAME GENE HOWEVER, THE VARIATION OF THESE GENES ARE DIFFERENT

EX: WILL BOTH CODE FOR SAME GENE (EYE COLOR) BIT 2 DIFFERENT COLORS

Question 3

AT WHICH STAGE DOES RECOMBINATION HAPPEN?

Answer 3

PROPHASE.

THE PROCESS OF RECOMBINATION ONLY HAPPENS IN PROPHASE I. RECOMBINATION IS REFERRING TO WHEN HOMOLOGOUS CHROMOSOMES UNDERGO SYNAPSIS + CROSSING OVER. RECOMBINATION IN SHORT IS THE EXCHANGE OF DNA INFO BETWEEN 2 HOMOLOGOUS CHROMOSOMES.

Question 4

TRUE OR FALSE.
MEIOSIS I IS THE DIVISION OF ONE DIPLOID PARENT CELL INTO TWO HAPLOID DAUGHTER CELLS.

Answer 4

TRUE.

MEIOSIS IS BROKEN DOWN INTO MEIOSIS I + MEIOSIS II.

MEIOSIS I END WITH 2 HAPLOID CELLS, THEY EACH HAVE ONLY ONE CHROMOSOME FROM EACH HOMOLOGOUS PAIR.

DURING MEIOSIS II, THESE 2 HAPLOID CELLS ARE DIVIDED EVEN FURTHER MAKING 4 TOTAL HAPOLOID DAUGHTER CELLS THAT ARE CALLED “GAMETES” OR SEX CELLS