🍐 2025 (8A) Meiosis

Meiosis

A type of cell division that produces four haploid cells from a single diploid cell through two rounds of division.

Open Ended

Discuss what the children in the photos have in common. Why do you think they have these similarities or differences?

Multiple Choice

Which statement best describes asexual reproduction?

• It requires two parents and produces genetically unique offspring.

• It occurs when a single organism produces offspring on its own, resulting in genetically identical offspring.

• It involves the fusion of gametes from two parents.

• It always results in offspring that are different from the parent.

Multiple Select

Select all statements that are true about sexual reproduction.

• It requires two organisms to share genetic material.

• It produces offspring that are genetically identical to the parents.

• It creates offspring that are genetically unique.

• It occurs without the involvement of gametes.

​Chromosome- Thread like structures that contain tightly coiled DNA

​Allele

Multiple Choice

Which structure connects two sister chromatids in a chromosome?

• Centromere

• Histone

• Gene

• Nucleus

Multiple Select

Which of the following statements about chromatids and chromosomes is/are correct?

• Chromatin condenses to form chromosomes during mitosis.

• A chromosome can consist of either one or two chromatids.

• Sister chromatids are identical copies joined at the centromere.

• Chromatids are only found in prokaryotic cells.

Multiple Choice

Which of the following statements correctly describes a diploid cell?

• Contains two sets of chromosomes, one from each parent

• Contains only one set of chromosomes

• Is always a gamete

• Has 23 chromosomes in humans

Multiple Choice

Which of the following statements about gamete cells is correct?

• Gamete cells are diploid and found in all body tissues.

• Gamete cells are haploid and only produced in reproductive organs.

• Gamete cells are diploid and produced during mitosis.

• Gamete cells are haploid and produced during mitosis.

Multiple Choice

Which of the following is NOT a characteristic of meiosis?

• Produces gametes (sex cells)

• Results in cells with half the number of chromosomes

• Results in 2 identical daughter cells

• Increases genetic diversity

Multiple Choice

During which phase of meiosis does Crossing over take place?

• Prophase I

• Metaphase I

• Anaphase I

• Telophase I

​Mendel’s Laws of Inheritance

1. Law of Segregation

• Each individual has two alleles for each gene.

• These two alleles separate during gamete (sperm or egg) formation, so that each gamete receives only one allele.

• When the gametes combine during fertilization, the offspring inherits one allele from each parent. 

• 2. Law of Independent Assortment

• Alleles for different traits are sorted into gametes independently of one another.

• For example, the inheritance of the gene for pea color does not affect the inheritance of the gene for pea shape.

• This law applies to genes that are not on the same chromosome; genes that are located close together on the same chromosome may not assort independently. 

Mendel's Laws of Inheritence

• 3. Law of Dominance

• Some alleles are dominant, while others are recessive.

• A dominant allele will always be expressed if it is present.

• A recessive trait is only expressed if an individual inherits two copies of the recessive allele (one from each parent).

​Monosomy

​Trisomy

Nondisjunction

​Down Syndrome Turner's Syndrome

DOL

Multiple Choice

Gametes produced by an organism contain a combination of genes from that organism. In every gamete, this combination is —

• the same because it is created from the same DNA

• the same because chromosomes are copied prior to meiosis

• different due to DNA replication prior to mitosis

• different due to independent assortment during meiosis

Multiple Choice

A cellular process is shown. Which statement best describes the significance of this process?

• The process allows organisms to grow and heal.

• The process produces clones of the parent organism.

• The process copies DNA before cell division.

• The process creates genetic variation in the resulting cells.

Multiple Choice

A cellular process is shown. Which of these is the most likely result of the process shown in the diagram?

• Chromosome replication will cease to avoid errors that result in mutations.

• Offspring will no longer express traits from previous generations.

• Gametes will contain new allele combinations.

• Chromatids will have less genetic variety.

Multiple Choice

Which process occurs between Step 2 and Step 3 and creates more genetic diversity in the resulting cells?

• Chromosome nondisjunction

• Genome replication

• Crossing over

• Chromosomal deletion

Multiple Choice

Giraffes (Giraffa camelopardalis) have 30 chromosomes in their somatic cells. How many chromosomes will each daughter cell have after the final step of meiosis?

• 15

• 30

• 10

• 20

Multiple Choice

Three processes that are required for sexual reproduction to occur are shown. Which table most accurately describes the importance of each process to sexual reproduction?

Multiple Choice

How does meiosis contribute to genetic diversity?

• By duplicating chromosomes

• By ensuring daughter cells are identical

• Through crossing over and independent assortment

• By producing cells with the same number of chromosomes as the parent cell