Meiosis

Question 1

Heredity

Answer 1

The passing of genes from one generation to the next

Question 2

Trait

Answer 2

A genetically determined characteristics

Question 3

Genetics

Answer 3

The study of heredity and heredity variation

Question 4

Locus

Answer 4

A gene’s specific location on a chromosome

Question 5

Somatic cells and how many chromosomes humans have?

Answer 5

Normal cells in an organism
Have 46 chromosome

Question 6

Gametes

Answer 6

Reproductive cells that pass genes(DNA) from generation to another

Question 7

Gene

Answer 7

If it inherited and causes a trait (phenotype), it’s a gene

Question 8

Asexual Reproduction

Answer 8

Parent is a single individual
**All cells are made by mitosis - all cells are genetically identical
The descendants (progeny) are genetically identical to the parents(clone)

Question 9

Pros and Cons of Asexual reproduction

Answer 9

Pros: Fast
less genetic expensive
Cons: Less genetic diversity in the population

Question 10

Sexual Reproduction

Answer 10

Two parents
**Gametes are made meiosis - gametes are not genetically identical to parent
Descendants are NOT genetical to parent

Question 11

Pros and Cons of Sexual Reproduction

Answer 11

Pros: More genetic diversity in population which can withstand environmental changes
much wider variety of phenotypes
Cons: Need to find a mate(energetically more expensive)

Question 12

Life Cycle

Answer 12

The series of stages in the reproductive history of an organism(from conception to production of its own offspring)

Question 13

Diploid

Answer 13

These are cells that contain two copies of each chromosome(46)

Question 14

There are 23 pairs of chromosomes. True/ False

Answer 14

True.

Question 15

Humans have 22 pairs of autosomal chromosomes and 1 pair of sex chromosomes (X and Y). True/ False

Answer 15

True.

Question 16

Homologous Chromosomes

Answer 16

Two chromosomes in a pair

Question 17

Alleles

Answer 17

These are genes, one from mother and one from father

Question 18

Haploid

Answer 18

Only one chromosome(23) in each cell(Gametes)

Question 19

Fertilization

Answer 19

Merging of two haploid gametes to form diploid zygote

Question 20

Sporophyte

Answer 20

Spore producing phase(asexual phase) and diploid phase

Question 21

Gametophyte

Answer 21

Haploid Phase or sexual phase

Question 22

Ploidy

Answer 22

The number of sets of chromosomes in a cell. **Humans somatic cells are diploid(2n)

Question 23

Identical twins have the same combination of alleles. True/False

Answer 23

True

Question 24

Chromosomes are counted by the number of centromeres. True/False

Answer 24

True

Question 25

What are the sources of genetic variation

Answer 25

Crossing Over(homologous recombination) in prophase 1 Independent Assortment of homologous (various combinations of maternal and paternal chromosomes) chromosomes at metaphase/anaphase 1 Random fertilization(not in meiosis but part of process)

Question 26

Recombinant Chromosomes/Cross over

Answer 26

The swapped sections of DNA between non-sister chromosomes.

Question 27

Cohesins

Answer 27

Hold sister chromatids together

Question 28

Recombination happens during the raveled stage of the chromosome (euchromatin). True/False

Answer 28

True

Question 29

Steps to Recombination

Answer 29

DNA strand breaks are made by proteins on non-sister chromatids Synaptonemal complex hold non-sister chromatids together Crossing over occurs Recombination occurs on both sets of non0-sister chromatids

Question 30

Synaptonemal Complex

Answer 30

are proteins that hold the non-sister chromatids together

Question 31

Chiasmata

Answer 31

These are regions where non-sister chromatids have swapped(crossovers occurred)

Question 32

Synapsis

Answer 32

The close fusion of homologous chromosomes

Question 33

The chromosomes are fully condensed at the end of interphase. True/False

Answer 33

False. The chromosomes are fully condensed at the end of prophase 1

Question 34

Prophase 1

Answer 34

Nuclear Envelope breakdown Mitotic spindle forms along with centrosome movement Crossover and recombination occurs (earlier prophase)

Question 35

Metaphase 1

Answer 35

Duplicated homologous chromosomes are aligned at the metaphase plate (this is random) microtubules attached to one pair of sister chromatids

Question 36

Anaphase 1

Answer 36

**Centromeres that hold homologous proteins together detach **Homologous chromosomes separate Cohesin proteins remain together kinetochore stays together

Question 37

Telophase 1 and Cytokinines

Answer 37

Each nucleus has a haploid set of duplicated chromosomes Each chromosome is a sister chromatids No duplication occurs before going into the next stage

Question 38

Prophase 2

Answer 38

Similar to prophase 1 Nuclear envelope breaks down, mitotic spindle forms, centrosomes move to the ends of the cell

Question 39

Metaphase 2

Answer 39

chromosomes are aligned at metaphase plate Sister chromatids attached by kinetochores to a microtubule Because of crossing over the sister chromatids are not identical

Question 40

Anaphase 2

Answer 40

Cohesins are broken down. Chromososmes are moved to opposite poles

Question 41

Telophase 2 and Cytokinesis 2

Answer 41

nuclei form, chromosomes decondense each cell has haploid haploid daughter cells form

Question 42

autosomal and sex chromosome cross over. True/False

Answer 42

False. Only autosomal chromosomes cross over