Meiosis and Sexual Reproduction
Meiosis and Sexual Reproduction
Guided Notes
To be used with Meiosis & Sexual Reproduction PPt
Genes and Heredity
______- the passing of traits from parents to offspring.
______- the study of heredity (the passing of traits)
Each human cell contains ____ thousand different genes
Karyotype is a chart of an
organism’s ______.
All ______genes are located
on _____ pairs of chromosomes.
Genes: factors that control organism ______or ______.
Genes are part of a chromosome containing the ______.
Genes are passed on from ______to ______.
Alleles: part of a ______that is located on a chromosome.
Example: Height(______)Tallness or shortness(______)
The alleles determine how each gene is ______.
There areat least ______alleles for one gene.
Locus: Location of a ______on a chromosome
Meiosis:
A type of cell division where the chromosome number is ______to half.
The process in which cells undergo ______dividing phases to form ______.
Meiosis only produces ______cells (______).
______are your sex cells. Your egg and sperm cells.
Gametes are your ______cells. Your ______and ______
Sexual reproduction (sperm + egg) produces a ______.
Diploid vs. Haploid:
Define Diploid:
What is the abbreviation for diploid? ______
Where are diploid cells found? ______The diploid # for humans is _____.
Define Haploid:
What is the abbreviation for haploid? _____ The haploid # for humans is _____.
Where are haploid cells found? ______and ______cells
OrganismDiploid #____Haploid #__
Human 46______
Chimpanzee 48______
Dog 78______
Fruit fly 8______
Garden pea 14______
Adder’s fern 1260______
Terms
•Gametes:
______or ______
•Gonads:
specialized organs in higher animals
where the______are made
•Ovaries:
______gonads
•Testes:
______gonads
Meiosis - Interphase
______phase.
______& ______grow
Chromatin ______
Non dividing phase
Chromatin Chromosome Homologous Chromosome
Homologous Chromosomes:
-a ______of chromosomes that contain genes for the same traits.
-one chromosome is from ______the other from ______.
-same ______& ______are in same location.
Meiosis I
Prophase 1
______become visible & pair up.
The nuclear membrane starts to ______.
______are present.
Meiosis I - continue
Prophase 1
______: the meeting of homologous chromosomes
Tetrads: the two pairs of homologous chromosomes.
______over: the exchange of chromosome pieces.
-Crossing over increases the ______of the offspring
-This is why the offspring of sexual reproduction show many variations
- Crossing over occurs only during ______
Metaphase 1:
Centrioles move to poles extending ______.
______attach to spindle fibers
in middle of cell.
Anaphase 1:
Cell is ______shaped
______chromosomes pull apart.
Telophase I/Cytokenesis:
Complete ______.
Cell is figure eight in shape
End of Meiosis I
______-cytoplasmic division of the cell occurs.
-ends the first stage of ______.
-at the end of meiosis I there are ______cells.
-ends the first stage of meiosis
-each ______cell contains the diploid number of chromosomes.
Meiosis II
Similar to mitosis but no ______& chromosome replication.
No pairing of ______chromosomes. Single chromosomes line up during metaphase II.
Diploid (2n) is reduced to ______(n)
Normally, homologous pairs of chromosomes separate and move toward opposite poles of the cell
What is this disorder called? ______
Define Nondisjunction: the failure of ______
______to ______.
Name of the disorder caused by the nondisjunction of the 21st chromosome:
What could the number of chromosomes be with someone with this condition? ______
According to the graph on the right that describes
mother’s age versus number of Down’s Syndrome
births/1000, explain the trend that is depicted.
______
Does Meiosis I or II have a greater rate of Down’s
Syndrome babies? ______
Mistakes in Mitosis can be Good
Polyploidy:
having an entire ______set of ______
-Will result in the ____ or ____ number of chromosomes
-Many plants are a result of polyploidy; ______& ______.
-
Summary
______is very similar to _____ divisions of mitosis.
The ______number (2n) of chromosomes is reduced by ______
to the ______number (n).
What is formed? ______and ______
What is the name of the process that occurs that causes variation?
______
Do variations occur in Mitosis? ______
Do variations occur in Meiosis? ______
Mitosis is associated with this type of reproduction: ______
Meiosis is associated with this type of reproduction: ______
What is the name of the process that produces sperm? ______
How many are produced? ______
What is the name of the process that produces eggs? ______
What is produced along with one egg? ______
